Reposting my CEL and idle problem! ahhh!

[ber55ber55]

Alright, so many of you have helped me with my CEL and idle problem. OR i should say, have tryed to help. I appreciate it all dont get me wrong. The old post has just gotten so confusing that I thought I would start a new thread and try this again...with less confusion

What I have replaced:
Spark plugs
Muffler
O2 Sensor
intake manifold gasket

What I have clean:
MAF or AFM whatever you wanna call it
ICV - with wd-40, brake cleaner and r/c car cleaner
throttle body
airfilter
plugs

What I have checked:
ICV - shock it around and the little thing inside moves ( you can hear it)
Check if o2 is in all the way
CHecked spark plugs - all good
injectors - ran injector clean like 3 times already - should be clean by now
Vacuum leaks - sprayed gasoline on the engine (seals leaks very well - dangerous though - actually how I found out the intake manifold gasket was bad) saw no problems NOTE: must spray off with water afterwards

SYMPTOMS:
CEL - in neutral or rolling in neutral or at a stop about 10 seconds to CEL pops on. I turn a/c on...goes off... i know why though. Also goes off if i tap the throttle or give throttle, but comes back 10 seconds later again.

BAD IDLE: when the car is cold starts fine and idles fine. when the car is totally hot also idles fine. Problem comes when the car was driven, got hot, stopped, started again about 15 min - hour after, the idle goes between 300 and 1200. But after given gas a little bit, and driving, it goes away...

OTHER NOTES TO CONSIDER:
No oil leaks
NEW MUFFLER - i have a new cat but havint installed it - dont really think thats the problem since the car doesnt choke or have a lose of any sort of power
Whn the thottle is just slightly taped in neutral by pedal or manually, the car almost dies
The exhaust coming out is very pulsy and sort of erratic
Car is barely passing smog, so cat will need to be replaced, but i doubt it is the reason for my problems
Idle is pretty rough overall
Some times the CEL doesnt come on at all
Always a lot of oil by the plug for the ICV (at the bottom) but not in the plug...just around it
Engine pulls strong, and gets good gas milage....between 19 and 24 mpg (ivew been gettin 22.6 lately- normally around 19.8 ish)

I have done the stomp test - code 1222
Bavauto diagnotic tool - read lambda control
Did shogun reset - did nothing

I am going to recker/junkyard on sat - let me know what I should buy

ALSO : I have been told to check the purge valve - dont really know what that is....
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I have restored the interior - fixed the ceiling, the door panels, reglued and redied everything, restored the paint and windows and religiously cleaned an maintained this car. These are my final problems before I sell this car and buy a 1994 540i. Pleaser help!

[Ross]

Still sounds like ICV.
Do a compression test. She may just be tired.
Check for clogged cat by hooking vac guage and holding revs at a constant
speed, if vac drops off exhaust is restricted. This is very unlikely to be your trouble.
You can just plug the line to the purge valve to see if you have trouble there. DON'T plug the one to the tank.

[632 Regal]

first guess...vacum leak somewhere! (I know but thats what it sounds like)
second...fuel pressure, tap the line at the fuel rail, get a gage and check it.

[ber55ber55]

I have done a compression test....shes 100% fine...all cylinders are the same...wet and dry they were all alike....

I have heard about this "purge valve" I went to oem...and couldnt find it....
Alternate name?
Or can you describe what it looks like and where it is on a m20

[ber55ber55]

first guess...vacum leak somewhere! (I know but thats what it sounds like)
second...fuel pressure, tap the line at the fuel rail, get a gage and check it.

Is there a procedure or something to just "tap" into the fuel rail?
Where would I be able to "tap" it?
What kind of gage (fuel pressure gage i assume) but from where and how much will that ish cost me?

[Rus]

I'll second the fuel pressure check. A dying fuel pump in my 535i caused the CEL to come up with 1222 code whenever the engine was allowed to idle for a bit (about 10 seconds as you are describing). New fuel pump solved this issue.

[ber55ber55]

I'll second the fuel pressure check. A dying fuel pump in my 535i caused the CEL to come up with 1222 code whenever the engine was allowed to idle for a bit (about 10 seconds as you are describing). New fuel pump solved this issue.

This doesnt make sense though.
In my opinion, either the fuel pump works or it doesnt, right?

If i do replace it....would it fit from a 530, or 535 e34?

Basically, is there a universal fuel pump?

What tools will i need to remove it, and where is it located? (in the trunk under the mate?)

I will be making a trip to the junk yard for a vaccum line, sprayer nozzles, rubber boot, radiator level sensor, ICV, and now a fuel pump!!!!! hahaha and possible doorpanels if i find some nice ones.....anyone else need anything they want me to pick up why im there?

Im in the LA area

[ber55ber55]

Any other takers on the subject.....anyone else thinks its the fuel pump? just seems a little far out to me, because if it was the fuel pump I would assume I would have more problems then a check engine like coming on when im in idle

[Ausmpower]

Tps......tps>>>>>>>>>>>> tps!!!!!!!

Your Throttle Position Switch is giving an intermittent throttle closed (idle) signal....... CHECK THAT FIRST!

Sick fuel pump would give a miss fire at full throttle high RPM......

[Rus]

This doesnt make sense though.
In my opinion, either the fuel pump works or it doesnt, right?

If i do replace it....would it fit from a 530, or 535 e34?

Basically, is there a universal fuel pump?

What tools will i need to remove it, and where is it located? (in the trunk under the mate?)

I will be making a trip to the junk yard for a vaccum line, sprayer nozzles, rubber boot, radiator level sensor, ICV, and now a fuel pump!!!!! hahaha and possible doorpanels if i find some nice ones.....anyone else need anything they want me to pick up why im there?

Im in the LA area

Please do take into consideration that we have different engines installed. However, the pressure that my pump created was nearly half of the required pressure for normal engine operation. My best explanation for the 1222 code is that at idle the fuel pressure was too low, not enough fuel entered the engine, thus causing a lean condition which triggered the 1222 Lambda 1 Control code. I rigged up a fuel pressure gauge for about 30 dollars using a gauge kit from autozone and a t-fitting. The fuel pump can fail completely, or as in my case fail to generate enough pressure. Check www.realoem.com for the correct fitting fuel pump. They may be interchangeable. Good luck!

[Ausmpower]

Please do take into consideration that we have different engines installed. However, the pressure that my pump created was nearly half of the required pressure for normal engine operation. My best explanation for the 1222 code is that at idle the fuel pressure was too low, not enough fuel entered the engine, thus causing a lean condition which triggered the 1222 Lambda 1 Control code. I rigged up a fuel pressure gauge for about 30 dollars using a gauge kit from autozone and a t-fitting. The fuel pump can fail completely, or as in my case fail to generate enough pressure. Check www.realoem.com for the correct fitting fuel pump. They may be interchangeable. Good luck!


Usually a weak fuel pump shows up at full throttle not idle as the injectors are flowing 10 x the amount of fuel at WOT compared to idle.


535's are know to suffer voltage drop at the pump when at idle are you sure this wasn't your problem? changing the pump out may have just helped because the pump power terminals would have been moved around.

[ber55ber55]

Yeah i highly dont believe it would be the fuel pump, no offense rus, but hey, you may be right. TPS i dont know either. Its not the same as on a m50 .Mine only has open, half, closed....its not variable like on a m50. But im sure i could find a cheap. ill try it....

do you think this could be the problem for both...the idle issue and the CEL?

from the beginning i have had thought about TPS or ICV....i just dont want to spend money on something when im not 100% sure.....

[Ausmpower]

Yes........ I reckon both conditions are caused by the TPS not signalling when the throttle is closed (idle positon)or is signalling idle intermitently.

Here's why:

Condition 1 Idle: the DME will hunt around for the correct mixtures at any throttle setting above idle, because gas flow through the manifold is under high vacuum with the throttle shut (but TPS off idle) the dme adjusts as it normally would in cruise mode. But because the gas flow is so slow at idle the dme will overfuel then under fuel is cycles hence your idle issue.

Condition# 2 CEL:

Because the dme is trying to work out the correct a/f ratio for a light engine load (cruise) at idle instead of running in the proper 'Idle mode', the DME will log an O2 fault because of the delay between adding fuel and getting a response from the O2 sensor caused by the closed throttle induced high vacuum. Basicaly the DME adds more fuel and waits for a response from the O2 sensor. After a period of time hunting up and down the fuel map without 'in sync' responses from the O2 sensor the DME will log the lambda fault code.

P.s I have an M30 535 which runs exactly the same AFM, TPS, ICV etc setup as your M20 (which is essentialy an M30 minus 2 cylinders!)

HTH

I just thought of a simple check for you to try (works with manual trans so should work with an auto).

When you are rolling along at say 60 kph and take your foot completely of the throttle (but stay in gear) does your economy meter ALWAYS swing to 0 mpg??

If not it is definitely your TPS as the DME cuts all fuel to the motor on over run when the throttle is closed (ONLY if the DME get the throttle closed signal from the TPS) above 10 kph.

If the gauge IS always going to '0' then we need to look elsewhere...... Post back here or PM me with your findings on this.

Ross

[dukester]

Hi, I just went through a similar sort of problem with my M20. When I changed my TBelt, I developed a similar bad idle, cutting out, totally random problem set. Turned out that I had inadvertantly broken the inductor pickup on the #6 plugwire that syncs the injectors. Changed it and runs fine now.
Give it a look, they get very brittle with age and are surprisingly easy to break.

[ber55ber55]

alright so the TPS wasnt broken. It was just not adjusted correctly, so the switch was sending the wrong message. The idle is completly fixed, but the CEL is randomly coming on. I didnt get a chance to read to codes tonight because it was too late, but tomorrow morning i will see what up now, because it took way longer then 10 seconds for the light to come on. The throttle gasket is bad, so maybe that is way. I will replace some maintaince parts on thursday that i purchased from BMA which include washer nozzles, vaccum hose, clips for the interior, readiator level sensor, rubber connector for the ICV, and tiny interior caps. I will post pics of the car when im done re-dying and glueing the interior and the engine is running 100%. By the way, the idle speed is around 650 now, which as far as I remember is the right speed. The overall idle is smoother, the car runs better, and Im getting better gas mileage. All because the TPS was misadjusted. can you believe that?? by like 5 cm, and the car feels like a whole different car. BMW......very sensitive, yet very reliable, unlike women...haha...thanks for all the help guys!!!!!!!

[Ausmpower]

alright so the TPS wasnt broken. It was just not adjusted correctly, so the switch was sending the wrong message. The idle is completly fixed, but the CEL is randomly coming on. I didnt get a chance to read to codes tonight because it was too late, but tomorrow morning i will see what up now, because it took way longer then 10 seconds for the light to come on. The throttle gasket is bad, so maybe that is way. I will replace some maintaince parts on thursday that i purchased from BMA which include washer nozzles, vaccum hose, clips for the interior, readiator level sensor, rubber connector for the ICV, and tiny interior caps. I will post pics of the car when im done re-dying and glueing the interior and the engine is running 100%. By the way, the idle speed is around 650 now, which as far as I remember is the right speed. The overall idle is smoother, the car runs better, and Im getting better gas mileage. All because the TPS was misadjusted. can you believe that?? by like 5 cm, and the car feels like a whole different car. BMW......very sensitive, yet very reliable, unlike women...haha...thanks for all the help guys!!!!!!!

Where's the: "thanks AusM you nailed the idle issue for me!"

I told you the TPS was on the dodge......:D

CEL could be from the TPS fault..... or have you already reset the DME ?

[ber55ber55]

No for sure AusM, thank you for real. I was just giving a general thanks. By the way....BMA had the TPS for $55...those guys are awesome.....and they know my dad really well cuz hes down there all the time. anyway, thanks a bunch for real. IF your ever in california ill have my brazilian wife hook you up with some broads haha....just playin....unless you want em

BTW...reset the DME......you mean the shogun reset thingy...correct...?