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Discussion Starter #1
Running LEAN...WHY!?!?!

My problems are well-documentes in this forum, but I'll summarize.

Pinging. Serious bog and intake backfire when starting out from a stop. Missing, bucking, and jerking when opening the throttle at less than 2000 RPM's. Shuddering while accelerating on the top end.

Since these symptoms started, I have tried MANY, MANY things to fix it.

New Autolite platinum plugs.

New Ford Racing wires.

New coil pack.

New fuel filter.

New fuel pump.

Fuel Injector pressure sensor replaced.

Last weekend I had the injectors cleaned thoroughly with a pressurized 3M treatment, and reset all the codes. We ran a fuel pressure check, and found a steady 30 PSI at idle, and a 40 PSI spike when blipping the throttle. I was getting a CEL, and the codes were for lean condition, lower O2 sensor, and IMRC stuck open. I checked the IMRC; the butterflies were closed at idle and partial throttle, so I think the IMRC code was a one-time fluke. The lean condition code is a given, being how the thing nearly blasts the filter off the intake every time I take off. The lower O2 sensor has me stumped, because I have a MIL eliminator on that.

To this point, nothing has even touched the problem. I only have a few things left in the fuel delivery system that have not been replaced: injectors, MAF sensor, and IMRC.

I don't think the IMRC would give the shuddering top-end acceleration as well as the low-end intake backfires, so I'm pretty much ruling that out.

I have thoroughly cleaned the MAF; although if it is truly bad, that wouldn't fix it. Maybe.

My most likely candidate is a bad injector or two, not giving a strong enough pulse when the throttle opens. So I'm getting ready to replace these.

Before I incur the expense, does anyone (DanG, I'm looking in your direction) have any ideas about what could be leaning this thing out? Would a bad O2 sensor cause this kind of trouble? Would a weak battery cause it (I think my battery might be compromised since my last alternator failure a while back, and the cold weather is axascerbating it)?

How about the timing chain tensioner? I guess a loose chain would affect the timing, but wouldn't it make a racket? Is there an easy way to tell if your timing is off?

Sorry this post is so scattershot. I'm just running out of ideas (and, not to mention, money)...

Any thoughts, opinions, or help are MUCH APPRECIATED.

**Fix in the last post...**
 

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RE:Running LEAN...WHY!?!?!

Im not really sure.. but could it be a vacumm line? It sounds like you covered most other things already. On the low end i bad IACV might be adding to the bogging, but i think that would make it run rich. If all else fails trade it in to a poor unsuspecting dealer :)

Have you physically removed the injectors? If they were built up enough, the pressurized cleaner might not have got them all the way clean. I have used a cleaner called chem-dip (i think) to clean copper jets for carburetors and it works great. You just soak them for a few hours and everything falls off.
 

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RE: Running LEAN...WHY!?!?!

A bad 02 sensor could DEFINITELY cause your issues.

Get an auto tap or some form of obd-2 scan tool and watch all 4 o2 sensors cycle.
My guess is you have a slow or o2 coming to the end of its life.
 

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RE:Running LEAN...WHY!?!?!

Bennet,

I've used the obd-2 tool from http://www.obd-2.com... pretty useful, and I think I'm just scratching the surface with it. Might be worth picking one up as CougarGT suggested. You would need a laptop, or a really long cable.... but laptop is for SURE best, because you can go out and drive around, and it'll track what you want it to track.

Another suggestion... maybe that 3M injector cleaner did not clean other buildups in your car? If that were the case, maybe you have a lot of carbon buildup or something else that is causing higher compression, detonation, etc... I know the OBD-2 tool can plot your O2 data over time, but not sure about air/fuel mixture. If the O2's are faulty, obviously it will show you their wrong readings, which might just throw you off track.

Massiv.
 

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Discussion Starter #5
RE:Running LEAN...WHY!?!?!

Oh, here's another tid-bit;

After we cleaned the injectors and reset the codes, it ran TERRIBLY. WAY worse than before. Opening the throttle AT ALL caused it to go into spasms. Then, as soon as the CEL came on, it smoothed out considerably. The problem did not go away, but it went from "all through the powerband" to only the low and high end problems I have right now.

I gather that the CEL causes the ECU to richen the fuel mix, which makes sense if the lean condition is causing the problems.

If I open the throttle GRADUALLY, it's just fine. It's only when I open the throttle quickly, or a lot, that it has problems. The times when I let in a lot of air and it needs a lot of fuel QUICKLY to balance it out.
 

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RE: Running LEAN...WHY!?!?!

Bennet,

Someone else on here must live near you. Why not hookup with another Cougar owner and swap the easy to swap stuff. MAF, plugs, wires, ignition coil, TB if you want. Then see how you're doing. If you want to drive to Toronto (4-6 hours for you I think), you're welcome to swap all your parts with mine... This way, you might be able to track down which part, or parts, are the cause.

Massiv.
 

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RE:Running LEAN...WHY!?!?!

I agree with CougarGT. O2 sensor. Even tho you have a MIL eliminator on it, that just keeps the light from coming on..it doesn't make the sensor work correctly.

Mike
 

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RE:Running LEAN...WHY!?!?!

Are you getting a flashing CEL?

A failing or failed injector would more than likely cause a misfire, which would be seen by the misfire monitor. Once this happens the CEL will flash.
 

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Discussion Starter #10
RE:Running LEAN...WHY!?!?!

Originally posted by: CougarGT
Are you getting a flashing CEL?

A failing or failed injector would more than likely cause a misfire, which would be seen by the misfire monitor. Once this happens the CEL will flash.
No. I have a steady CEL.

I replaced the offending O2 sensor today, and it still pops at takeoff, so it's not fixed - yet. I did reset the computer, so maybe after it "learns" the fuel maps again, it will settle down. I'll know more after tomorrow's commute.

Oddly, I had the codes read at Autozone yesterday, and had 2: one for the O2 sensor again, and one for the idle speed actuator...

Exactly what is this, and what does it do?
 

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RE: Running LEAN...WHY!?!?!

Idle Speed Actuator = IACV Idle Air Control Valve

It is possible that your MIL Eliminators are on the fritz. Pull them and verify the circuitry.
What is the exact o2 code?

We'll get to the bottom of this!

Matt
 

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RE: Running LEAN...WHY!?!?!

Not sure what the code was EXACTLY, but it was something like "Oxygen Sensor Circuit Malfunction, bank 1 sensor 2".

I was thinking about switching the MIL eliminators from front to back and back to front, and seeing if the bank 2 sensor goes off. If the code comes back again, that's what will happen.

I have those sweet MIL's from CTA Motorsports (or maybe SP Motorsports - can't remember), which seem to be VERY well sealed.

Update: the CEL came back on first thing this morning, and nothing has changed.

I'm getting new injectors. I don't think one is "dead," but posibly losing its resistance and not delivering the volume it should. Like it doesn't vary its pulse speed and volume with the changing MAF and TPS readings, and only has one "setting," so to speak.
 

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RE:Running LEAN...WHY!?!?!

Originally posted by: Bennett9000
Not sure what the code was EXACTLY, but it was something like "Oxygen Sensor Circuit Malfunction, bank 1 sensor 2".

I was thinking about switching the MIL eliminators from front to back and back to front, and seeing if the bank 2 sensor goes off. If the code comes back again, that's what will happen.

I have those sweet MIL's from CTA Motorsports (or maybe SP Motorsports - can't remember), which seem to be VERY well sealed.

Update: the CEL came back on first thing this morning, and nothing has changed.

I'm getting new injectors. I don't think one is "dead," but posibly losing its resistance and not delivering the volume it should. Like it doesn't vary its pulse speed and volume with the changing MAF and TPS readings, and only has one "setting," so to speak.

Get a DVOM and test the resistance of each injector.
 

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RE: Running LEAN...WHY!?!?!

Not sure what a DVOM is...but I think it's a multitester?

I did check the resistance of each injector with a multitester. Cylinder 1 was reading about 14.7 Ohms, whereas cylinders 2-6 were reading about 15.0 to 15.1. I have heard that anything within .5 Ohms is still in spec. which this IS, technically...but anyway. I got a deal on a set of green SVT injectors that are going in this coming weekend, hopefully.

And Massiv, yeah - I think I'll try out someone else's MAF sensor and take it for a test drive and see what happens there.

What about the retarded timing? Has anyone ever had a timing chain tensioner go bad? I hate to imagine that, but it's nagging away at the back of my mind all the time...
 

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RE:Running LEAN...WHY!?!?!

Originally posted by: Bennett9000
Not sure what a DVOM is...but I think it's a multitester?

I did check the resistance of each injector with a multitester. Cylinder 1 was reading about 14.7 Ohms, whereas cylinders 2-6 were reading about 15.0 to 15.1. I have heard that anything within .5 Ohms is still in spec. which this IS, technically...but anyway. I got a deal on a set of green SVT injectors that are going in this coming weekend, hopefully.

And Massiv, yeah - I think I'll try out someone else's MAF sensor and take it for a test drive and see what happens there.

What about the retarded timing? Has anyone ever had a timing chain tensioner go bad? I hate to imagine that, but it's nagging away at the back of my mind all the time...
Adding 19lb injectors to a car that is already running bad is just going to complicate things. I would hold off on installing the 19's until you are positive it is the injectors at fault.

What are you going to do to compensate for the larger injectors? MAF(those generally cause a CEL)? SAFC? Chip?

You are comparing two differnt forms of timing. There is static timing - the mechanical relationship between the cams and crankshaft. Then there is ignition timing - the relationship between spark and piston location.
 

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RE:Running LEAN...WHY!?!?!

yea it's bad idea to run larger injectors on a car with a stock MAF or no calibrated chip. First swap out the MAF with somebody and see what happens. As for the IACV, it's possible that yours could be bad, as many cougar-owners have had to replace them before, but I've never heard of the IACV causing the problems you're having.

Mike
 

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Discussion Starter #17
RE:Running LEAN...WHY!?!?!

Originally posted by: 99CouGSweetRide
As for the IACV, it's possible that yours could be bad, as many cougar-owners have had to replace them before, but I've never heard of the IACV causing the problems you're having.

Mike
I thought so, too. And I have already replaced my IACV once already for moosing, about a year ago.
 

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RE: Running LEAN...WHY!?!?!

Hey Bennet...

Has the recent warm streak helped the problem any? Two thoughts:

First,When I did all that other cleaning, then reset the computer, I mentioned I had a pop after. Haven't had too many since, even on starts where I try to produce them. I think the computer is relearning the cleaned maf, and crankcase ventilation actually attached to the PCV (if that actually causes anything). Things are getting smoother.
Second, with this 32-34F weather, the car is very smooth down low... MUCH better than it was. I have to wait until we're back to -20C (5F) to see if it comes back.

Massiv.
 

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Discussion Starter #19
RE:Running LEAN...WHY!?!?!

NEW UPDATES.

So tonight I went out and bought some electrical parts cleaner and went to work. I took off the MAF and sprayed it out thoroughly. Cleaned out the IACV. Took off the TPS and knocked around on that. Went out for a drive, and it was just terrible. So, having nothing to lose, i pulled off the road, and UNPLUGGED THE MAF ENTIRELY. Besides not idling properly, the car ran PERFECTLY. No popping on takeoff, a good strong pull all the way to redline; everything.

So I'm going to trade MAF's with another Ohio NECO member in my area, and the truth will be known.

Predicting the solution - does anybody have a stock MAF they want to unload? Fordpartsonline lists them for $144, and on top of all the other crap I've bought for this thing in the last 2 months, I don't really want to incur that kind of expense just yet...
 

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RE:Running LEAN...WHY!?!?!

Originally posted by: Bennett9000
Not sure what a DVOM is...but I think it's a multitester?

I did check the resistance of each injector with a multitester. Cylinder 1 was reading about 14.7 Ohms, whereas cylinders 2-6 were reading about 15.0 to 15.1. I have heard that anything within .5 Ohms is still in spec. which this IS, technically...but anyway. I got a deal on a set of green SVT injectors that are going in this coming weekend, hopefully.

And Massiv, yeah - I think I'll try out someone else's MAF sensor and take it for a test drive and see what happens there.

What about the retarded timing? Has anyone ever had a timing chain tensioner go bad? I hate to imagine that, but it's nagging away at the back of my mind all the time...
DVOM - Digital Volt/Ohm Meter....??

Some of the engine codes may be misleading. When my IAT went out I pulled 3 or 4 different unrelated codes - clutch switch, cam sensor circuit, etc. After I replaced the IAT they all went away. Maybe you could check the resistance on the IAT. I don't remember what it should read at room temp. though. Maybe someone else knows.
 
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