DTC's came back

[Gorman]

Hi Guys; i've been datalogging and in the ecu memory were two DTC's. P0171 and P0174. Long term Lean, banks 1+2. I cancelled them but within 36 hours they returned. I don't think i have a vacuum leak. With SVT lite and headers, would this indicate the 17lb injectors are over 80% at high RPM ?. Any advice would be appreciated...I'm reading 160 grams per second air volume, read by MAF at about 6500 rpm..G.

[cpapashley]

Hi Guys; i've been datalogging and in the ecu memory were two DTC's. P0171 and P0174. Long term Lean, banks 1+2. I cancelled them but within 36 hours they returned. I don't think i have a vacuum leak. With SVT lite and headers, would this indicate the 17lb injectors are over 80% at high RPM ?. Any advice would be appreciated...I'm reading 160 grams per second air volume, read by MAF at about 6500 rpm..G.

So what is your air intake temperature at the moment??

I doubt it would be maxing out though at that, Just one thing did you reset the ecu since you have put on the SVT intake?

[Gorman]

Hi A. the intake temperature is ...well last night it was 1 to 5*c and during the day...9 to 15*c. I have an airbox fitted behind the fender ...so it scoops up alot of air. The faster i go, the lower intake temp is. SVT stuff has been on months and months, gonna reset everything again and see...Anyone specifically know if 160grams a sec. is over 80% duty on the injectors. I have the 19lb injectors ready and the down time over christmas..chitty chitty bang bang and mary poppins can wait 'til next year !! G. Oh! happy christmas A. Hope you and yours have a great time....in the blazing sunshine ..you lucky people.

[jaged]

is there any kind of chip or tune in the equation. ive been running svt lite and headers for years now, but i have a chip in there to even thing out

[Gorman]

is there any kind of chip or tune in the equation. ive been running svt lite and headers for years now, but i have a chip in there to even thing out
Hi J. what power do you get from your setup ? i don't have it chipped or remapped. I was thinking of waiting 'til the cams go in to do that...i don't have a flash tool, just a logging interface tool ..otherwise i would have an intermediate mapping flashed on there. G.

[Gorman]

...well i reset the ECU and within 24 hrs the long term lean codes came back again. Please, can someone spell out the implications to me..oh and the best course of action..thanks G.

[cpapashley]

Hi A. the intake temperature is ...well last night it was 1 to 5*f and during the day...9 to 15*f. I have an airbox fitted behind the fender ...so it scoops up alot of air. The faster i go, the lower intake temp is. SVT stuff has been on months and months, gonna reset everything again and see...Anyone specifically know if 160grams a sec. is over 80% duty on the injectors. I have the 19lb injectors ready and the down time over christmas..chitty chitty bang bang and mary poppins can wait 'til next year !! G. Oh! happy christmas A. Hope you and yours have a great time....in the blazing sunshine ..you lucky people.


Hope you have a great christmas as well, always a special time of year reflecting on the birth of Christ.

Wish I new a little more on these calculations, I know Tom (aka warmonger) has some great worksheets that do these types of calculations. 160g/sec is probably in excess of 80% duty as well I would think, maybe up round the 90%. From memory it went something like 17lb injectors are around 17lb/hr of air which is around the 130g/sec. Might be wrong there as these calcs are a bit new to me. But I think I am learning. :confused:

Here is that link for Tom's great page with lots of excel spreadsheets to keep you busy until next christmas. ;)

Tom (http://www.rumodded.com/warmonger/index.htm)

Sorry I cannot give you a definitive answer, it seems most of those on the forum have gone very quiet....

[Gorman]

..thanks for that A. 130g of air for 17lbers gives somewhere to start from. Maybe i should reload the program and choose imperial. Worth a try i suppose. G.

[cpapashley]

..thanks for that A. 130g of air for 17lbers gives somewhere to start from. Maybe i should reload the program and choose imperial. Worth a try i suppose. G.

I did find a great page for converting all that stuff.

Just in the middle of Christmas eve, with all the kids....

will check back after christmas...maybe I can find that link for you.

[cpapashley]

here tis.......


FUTEK Conversion Calculator | Unit Conversion Calculator | Online Conversion Calculator (http://www.futek.com/conversion.aspx?calc=fm)

[Gorman]

Hi A. thanks for that.. using FUTEK Conversion Calculator | Unit Conversion Calculator | Online Conversion Calculator (http://www.futek.com/conversion.aspx?calc=fm) and Stealth 316 - Air/Fuel Flow Calculators (http://www.stealth316.com/2-air-fuel-flow.htm) from these two calculators it seems your 130g a sec is spot on. (80% duty 17lb ers etc). Just plugged in 19 lb injectors and they need 146. 21's are 158 !! Looks like my airbox is really packing in the air. Good job i left an exit for excess air pressure...could have fried the engine with a very lean mixture !! Anyone care to run an eye over this to see if i have made an obvious mistake..if anyone has numbers for a wheel well CAI for comparison..please post. cheers G.

[cpapashley]

Hi A. thanks for that.. using FUTEK Conversion Calculator | Unit Conversion Calculator | Online Conversion Calculator (http://www.futek.com/conversion.aspx?calc=fm) and Stealth 316 - Air/Fuel Flow Calculators (http://www.stealth316.com/2-air-fuel-flow.htm) from these two calculators it seems your 130g a sec is spot on. (80% duty 17lb ers etc). Just plugged in 19 lb injectors and they need 146. 21's are 158 !! Looks like my airbox is really packing in the air. Good job i left an exit for excess air pressure...could have fried the engine with a very lean mixture !! Anyone care to run an eye over this to see if i have made an obvious mistake..if anyone has numbers for a wheel well CAI for comparison..please post. cheers G.

My only thought is what is the voltage?? just in case something wrong with the reading. Now I know it is not linear, but should be able to interpolate in some way to get a pretty good indication if something is a little out in the calcs.

So what Maf voltage were you running at?

Maybe a couple of figures would be good to work out if it tracks the same as mine or not.

[cpapashley]

Found a good thread with a couple of rates for various cars.

looks like svt is around the 160 g/sec or 21 lb/hr



flow rates (http://www.contour.org/archive/showflat.php?Cat=&Board=UBB6&Number=208019)

What is interesting is using that stealth calculation page, means that if my temperature is 9C as opposed to my current 30C I would flow 7% more air....No wonder the car feels so different in those cool spring/autumn evenings.

What amazes me is with a simple change of the SVT intake, the vehicle can flow 20% more air. I know there are lots of figures out there but that is a serious difference with something as simple as an intake. Certainly backs up so much what spook says about velocity/intake configuration.

Would just love to get a custom plenum done, or even better, just take the top of each end of my current 2.5l intake and somehow enlarge it 30% and see what sort of difference it would make to air flow. Wish I new more on this area.

[Gorman]

I haven't logged the MAF voltage yet..do you know what the max air volume for the stock MAF is ? The route i'm exploring is ram air system...volume of plenum is less important 'cos there is plenty of air coming in under slight pressure. I take it you can't see anything wrong with the numbers we figured ?.. You could always take a hacksaw to a spare UIM. Confirmation about the meaning of the long term fuel trims would still be appreciated thanks G.

[cpapashley]

I haven't logged the MAF voltage yet..do you know what the max air volume for the stock MAF is ? The route i'm exploring is ram air system...volume of plenum is less important 'cos there is plenty of air coming in under slight pressure. I take it you can't see anything wrong with the numbers we figured ?.. You could always take a hacksaw to a spare UIM. Confirmation about the meaning of the long term fuel trims would still be appreciated thanks G.

Must have missed your point on the ltft will check that tomorrow.

I will post up a pdf I have logged, seems to show interesting changes especially round the 5800rpm mark, wondering if some sort of reversion is occurring?? or is the cam profile useless??

[Gorman]

.. driving home everything began to make sense. I was reading that a rich mixture is good for torque at WOT. It also said slightly lean is good for power at part throttle. I remember posting after putting on my p+p 'ed 65mm TB that my throttle works well to half way...but going full throttle makes very little difference. 19 lbers are going on....hoping to make enough progress that i need 21's !!.. G.

[cpapashley]

.. driving home everything began to make sense. I was reading that a rich mixture is good for torque at WOT. It also said slightly lean is good for power at part throttle. I remember posting after putting on my p+p 'ed 65mm TB that my throttle works well to half way...but going full throttle makes very little difference. 19 lbers are going on....hoping to make enough progress that i need 21's !!.. G.


Sounds great, are you able to post up a list of mods. I am in the midst of choosing my future plans for the MPV, seeing there is this new product called sniper that may be able to directly tune the factory pcm, without the need for a piggyback. I am especially hopefull, seeing they boast that it will work with all eecv pcm's :cool:

Might not have to go greddy at all. It would work out similar cost if I connect up emanage and tune, as opposed to this "sniper option".

I would love to see some datalogs of your engine, and see the airflow vs mine, to see where the change in various mods have made a difference.

You can pm me the data, I am happy to do graphs....;)

[cpapashley]

Just on that lean code, about halfway down there is a nice little snippet of info on those codes from the mpv manual.

http://forum.mpvclub.com/viewtopic.php?t=6149&highlight=p0171

[Gorman]

mods wise; i have SVT lite with mustang TB. A set of headers, optimised y pipe and stock cat, (for quietness) and my airbox behind the fender. I feel it has lots of potential ( some hinted at ). I haven't put the optimised 34/35 LIM on or port matched anything yet. Gonna whip the cam cover off when i do the injectors and new harness, (old one's gonna get spliced for the 21 lb returnless injectors i have) just to check which cams i have....my car revs round to rev limiter far too quickly for me to change up sometimes... hoping someone put SVT cams in ( well you can always wish). If not, it's on the list for next year. Now i've got the data logging going, i can really see what works and what is imagined by my butt dyno. When i get the data logs worked out i'll send you some data...gonna need to work that out for a tune. I've wondered if you can flash with a logging tool...hoping it's the software, since you can cancel DTM's you must be 'talking' to the ecu. I'd love to see a pic of your headers..you must be the only one on NECO that has them !! Hope you had a great christmas and thanks for posting and keeping me company...G.

[cpapashley]

mods wise; i have SVT lite with mustang TB. A set of headers, optimised y pipe and stock cat, (for quietness) and my airbox behind the fender. I feel it has lots of potential ( some hinted at ). I haven't put the optimised 34/35 LIM on or port matched anything yet. Gonna whip the cam cover off when i do the injectors and new harness, (old one's gonna get spliced for the 21 lb returnless injectors i have) just to check which cams i have....my car revs round to rev limiter far too quickly for me to change up sometimes... hoping someone put SVT cams in ( well you can always wish). If not, it's on the list for next year. Now i've got the data logging going, i can really see what works and what is imagined by my butt dyno. When i get the data logs worked out i'll send you some data...gonna need to work that out for a tune. I've wondered if you can flash with a logging tool...hoping it's the software, since you can cancel DTM's you must be 'talking' to the ecu. I'd love to see a pic of your headers..you must be the only one on NECO that has them !! Hope you had a great christmas and thanks for posting and keeping me company...G.


Have you checked out sniper?? I am hoping it will work for me over her in Australia. Now that I have managed to get some datalogging.

Which system were you using for datalogging again??

[Gorman]

..i read the sniper thread a while ago, don't remember which device it requires. I'm using an ELM 320 pass thru logging tool and several free OBD 11 programs....none of them as comprehensive as SCT stuff. G.

[cpapashley]

..i read the sniper thread a while ago, don't remember which device it requires. I'm using an ELM 320 pass thru logging tool and several free OBD 11 programs....none of them as comprehensive as SCT stuff. G.


The ELM320 system will only read, and not write. The sniper writes, as does the SCT. The good thing about the sniper is that it works with all eecv systems, and they seem prepared to make some effort to provide tuning support. They have a simple template they can sell you so you can tune yourself. I have a tuner coming up to Brisbane soon from down south Melbourne. He is happy to see if we can get something working. The fact you can read through the elm320 means that sniper should work for you too. I would find out if there is someone close to you that is a dealer.

I do have some pictures of my exhaust somewhere.....

ahhh here is the thread....:biggrin:

http://www.newcougar.org/forums/2-5l-duratec-performance/101329-mazda-mpv-00-a-2.html

[SpookSVT]

Must have missed your point on the ltft will check that tomorrow.

I will post up a pdf I have logged, seems to show interesting changes especially round the 5800rpm mark, wondering if some sort of reversion is occurring?? or is the cam profile useless??

Check the calibration first but the header priamary/secondary lengths could be wrong. Looks more like a calibration issue though.

[cpapashley]

Check the calibration first but the header priamary/secondary lengths could be wrong. Looks more like a calibration issue though.

So I check the calibration by....???

Sorry for the newb like question but being able to datalog is all so new to me. Checking the calibration sounds like something i would need a piece of equipment for, or can this NGS system do that in some way??

always happy to learn new skills...;)

[SpookSVT]

Calibration and tune are synonymous to me...

See if you can datalog the A/F ratio and check if there is a dip/spike in the fuel curve. That might be causing that loss of power around 5800RPM.

When you go to tune and it seems your throwing large amounts of fuel at it to get the curve back in shape, this could be an indication of over scavenging. There is an over abundance of low pressure present at the exhaust port at exhaust TDC/overlap. Decreasing overlap or changing pipe lengths to tune a different RPM would remedy this.

Did your fabricatior build to fit or are these tuned to a specific RPM? Pipe lengths and diameter would help as well.

[cpapashley]

Calibration and tune are synonymous to me...

See if you can datalog the A/F ratio and check if there is a dip/spike in the fuel curve. That might be causing that loss of power around 5800RPM.

When you go to tune and it seems your throwing large amounts of fuel at it to get the curve back in shape, this could be an indication of over scavenging. There is an over abundance of low pressure present at the exhaust port at exhaust TDC/overlap. Decreasing overlap or changing pipe lengths to tune a different RPM would remedy this.

Did your fabricatior build to fit or are these tuned to a specific RPM? Pipe lengths and diameter would help as well.


Tune...I wish, hopefully soon though, at the moment only datalogging. Will be getting a wideband when I finally get the ability to tune.

As far as the headers, I specifically requested that they be best throughout the rev range especially peak torque on to redline. Now I know that he requested engine size/combustion chamber size to work out the size of the individual primary pipes. Now he also worked out the equal length secondary pipes based on the same information. Not too sure how he did all that really, at that point just paid the money for the guy that came most recommended as able to construct a set of headers to suit my vehicle. His only comment to me was that with v6, he found the best gains were had with equal length primary and secondary pipes. He felt it was vastly superior to just a set of primary pipes.

If you can direct me to somewhere as to what formula he is likely to have used that would be great.

Keep in mind at the moment I still have the standard CAT

http://img.photobucket.com/albums/v202/arcruiser/PICT0031mod.jpg

That huge thing and the rest of the exhaust is standard. Which will be getting updated with a hi flow metallic cat and a straight through exhaust.

I am hoping that if it is problems it is caused by the rest of the back pressure in the exhaust. What do you think??

Will clean the MAF, and have another run in the next week to see if I can see something. I will also log the MAF voltage, part of the problem is the speed with which it updates, but will reduce the number of inputs to see if I can get a better picture.

Really appreciate your input spook.

[SpookSVT]

I'm sorry, I thought you posted a power curve. :banghead: That won't be the case then...

There is quite a few formula. Temperature of the medium in which the wave passes through will have a significant effect on the speed of the wave and thus the length of the tube. There's the ones I have from 'Scientific Design of Exhaust and Intake Systems' which are a bit complex and I don't have access to tools to get some of the required information (EGT, contents of the exhaust gas, etc..).

So to simplify the ordeal I have a header design program which is in the 90+ percentile in accuracy. There are some more basic formula available.

Also, an incorrectly tuned priamry length can return a positive pressure wave at overlap which can hurt cylinder filling.

You can try dropping the exhaust system after the y-pipe and then datalog to see if that dip clears up. Then you would know if it is indeed backpressure.

[cpapashley]

I'm sorry, I thought you posted a power curve. :banghead: That won't be the case then...

There is quite a few formula. Temperature of the medium in which the wave passes through will have a significant effect on the speed of the wave and thus the length of the tube. There's the ones I have from 'Scientific Design of Exhaust and Intake Systems' which are a bit complex and I don't have access to tools to get some of the required information (EGT, contents of the exhaust gas, etc..).

So to simplify the ordeal I have a header design program which is in the 90+ percentile in accuracy. There are some more basic formula available.

Also, an incorrectly tuned priamry length can return a positive pressure wave at overlap which can hurt cylinder filling.

You can try dropping the exhaust system after the y-pipe and then datalog to see if that dip clears up. Then you would know if it is indeed backpressure.

Found this on line

Principles of Exhaust Header Design - HCP - Pontiac Forums (http://hardcorepontiacs.com/forum/1636-principles-exhaust-header-design.html)

So I will check out the primary's and see if they follow this formulae at all.

If you have anything different, maybe just pm me with the formulae. When I get under the car to change the o2 sensors in the next week, I will take some measurements of what I have. I guess in a way it is all after the fact, but at least I can confirm if the extractors are hurting or helping.

As far as dropping the exhaust, only just over a week until I get the rest of the exhaust on, i think I will wait till then, the neighbours will appreciate...;) my patience.

[Gorman]

http://www.newcougar.org/forums/2-5l-duratec-performance/101329-mazda-mpv-00-a-2.html[/URL]Hey A. nice job. Have you thought about a true dual exhaust system using two stock cats instead of one sports cat ?,, G.

[cpapashley]

Hey A. nice job. Have you thought about a true dual exhaust system using two stock cats instead of one sports cat ?,, G.

;)

Sorry to hijack the thread there G, interesting thought, but for me I think in australia that would cost easily double what I am proposing. I am just happy that I can get this for around the $500aud. Standard CATs cost the same as the hi flow I am getting. Two silencers etc etc just would blow out the cost for me.

I am pretty sure with the 2.5l the 2 1/2" single should be fine.

[Gorman]

...sorry i meant using another stock exhaust system fabricated to make dual pipe system...G.

[cpapashley]

...sorry i meant using another stock exhaust system fabricated to make dual pipe system...G.

You are full of good ideas G. That was actually the way I was heading in some ways, was going to get a second hand system of the local Ford's. It was when I realised that someone I knew had an exhaust shop close by that I thought I would go this way.

Something for me to think about if I upgrade some time to a 3.0l :biggrin:

[Gorman]

... Ok back to the thread. I fitted the 19 lb injectors, a new engine harness (injector plug broken on the old one) and port matched the UIM to the lower. I put on the plug wires i bought from cougarguy939 (thanks the're great). I've reset the ECU..so now we wait to see if the P0171/4 codes come back...G.

[cpapashley]

... Ok back to the thread. I fitted the 19 lb injectors, a new engine harness (injector plug broken on the old one) and port matched the UIM to the lower. I put on the plug wires i bought from cougarguy939 (thanks the're great). I've reset the ECU..so now we wait to see if the P0171/4 codes come back...G.

I want to know if you are flowing more air at all?? Be so good to look at some datalogs, anyway you can send me some files at all. Surely the pc can spit out some csv files or something. Just send them direct to my email if you like. I will find the time to graph etc etc....:)

[Gorman]

csv... i'll have to look that one up. 48 hrs+ and no codes at all...:biggrin: G.

[cpapashley]

csv... i'll have to look that one up. 48 hrs+ and no codes at all...:biggrin: G.

I think usually two driving cycles, you should also be able to check pending codes as well, in this NGS system I have it has a FD prefix for the item. Not too sure if that is available on the ELM system or not.

[Gorman]

..ok csv, comma separated values. I've just got the software for datalogging...and my floppy has decided to go on strike :mad:. Anyhow...72 hrs+ and some spirited driving later...no codes at all :biggrin:. Not sure if i had a problem which was corrected during the work...but peace of mind with the injectors and having an UIM ready ported for a GB max extrude is great.. G.

[gamiller]

I haven't logged the MAF voltage yet..do you know what the max air volume for the stock MAF is ?

I'm coming late to the party, but Joey of Nautilus Performance (a.k.a. BurritaSVT) told me that the OEM MAF maxes out at 35 lbs/min. If you've done the rest of the SVT conversion, it sounds like the 19 lb injectors will work nicely. Good luck!

[cpapashley]

Hi, G

notice in that other thread there was a bit of heat on the codes, the 19lb wont work unless there is something to tune with. With the MAF having so much capacity it means to me that something like a greddy/safc would work fine as an interim, if you don't have a means to flash the pcm.

I will say though you need to make sure that there is no intake leak, and that those oem o2 sensors are all good, also that the MAF is ok. But from memory you checked all that.

Just check all those intake spots with a spray of brake cleaner to see if there is any leaks at all??

[Gorman]

Hi, G

notice in that other thread there was a bit of heat on the codes, the 19lb wont work unless there is something to tune with. With the MAF having so much capacity it means to me that something like a greddy/safc would work fine as an interim, if you don't have a means to flash the pcm.

I will say though you need to make sure that there is no intake leak, and that those oem o2 sensors are all good, also that the MAF is ok. But from memory you checked all that. Well A. it's over a week and the codes have not come back. I only said that there may have been a leak..the car showed no symptoms at all of an air leak when i had those codes It did 140mph..it would not go that fast with an air leak.. I believe my sensors are ok..they tally with the readouts i get from emissions tests. The 160g / sec equals 24lbs a min of air..maf goes to 35lbs , no prob there then. The car runs OK now but only reaches 110. So.. it runs very smoothly, idles fine..but does need a tune/injector constant table update... I think what you said about open loop and closed loop running is proved by this. Personally i prefer to have to drive slowly for a while with the 19's than have the 17's and the risk of overheating and engine failiure when overtaking at high rev's in 3rd...G.

[cpapashley]

:eek:

where did you get to drive at 140mph.....

I think I would like to come and visit...:)


I think it may be time for a tune, but seeing you are already going down the path of doing a lot yourself, why don't you get a wideband hooked up and get one of the less expensive alternatives for tuning, and DIY. I know all the rage on here is to go to a dyno, but you definitely seem like someone who would have a good time tuning. Lots of help in various places to tune correctly etc.

I have had a chance to go and get some more airflow info after getting the exhaust in.

Interesting how the airflow has smoothed out significantly all through the rev range now, and significantly improved in the lower revs. Will have to take some time to log some lower revs, just haven't been bothered as they have been so erratic, seem so much smoother now. Interesting.

Bit more airflow as well than before. I have obviously reached the peak of this manifold. But interestingly at peak torque I am up around 95% Volumetric efficiency, and I am above 90% v/e between low revs and 6150rpm. Sounds like everything is running quite well in there. It would be so good to compare some info from yours. I realise that temperatures are so different, and I know a 10C difference for may makes a huge difference. So I am at 28C when I have been doing the tests. I am sure it would not be to hard to factor in your details and compare apples with apples. should be able to adjust for the difference of temperature, afterall it is only a calculation.

[Gorman]

Hi A. since this is a public forum, i can't say too much on certain subjects. What i can say is, i remember reading that sighting an air filter in the wheel well is a poor choice. It said that this was a low air pressure area. It meant the engine was sucking air in from a vacuum..effectively. Try turning your air intake round and face it into the wind...( just like an F1 and WRC cars do) $1 says your airflow chart will look a little different !! If you design your scoop so water is forced down and out of a drain no water should reach your MAF. A vortex is another way to separate water and debris from the air...let playtime begin..G.

[Gorman]

Well A. it's over a week and the codes have not come back. I only said that there may have been a leak..the car showed no symptoms at all of an air leak when i had those codes It did 140mph..it would not go that fast with an air leak.. I believe my sensors are ok..they tally with the readouts i get from emissions tests. The 160g / sec equals 24lbs a min of air..maf goes to 35lbs , no prob there then. The car runs OK now but only reaches 110. So.. it runs very smoothly, idles fine..but does need a tune/injector constant table update... I think what you said about open loop and closed loop running is proved by this. Personally i prefer to have to drive slowly for a while with the 19's than have the 17's and the risk of overheating and engine failiure when overtaking at high rev's in 3rd...G. ok quick update. the 19's have been in for two whole months. The car runs very smoothly. Top speed is now easily reached. The ecu does not seem to have a problem coping. Foot down acceleration in 5th is as responsive as it ever was. That said..i have now bought an ecu from an svt and i'm going to fit it and see if it makes any difference to the running of the car. By the way; the lean codes have not come back since christmas. Make of that, what you will..(no point getting brow beaten again)...cheers G.