idle/startup stuff

[pepe m42]

Hi!

Problem: at each startup ( cold/hot ) the RPM. is low and hesitate ( it's feels like it want to stop, bust it jumps back to normal affter about 30-60 sec. and then it's perfect, its okay until the next startup.)

Even if i stop the engine for only a sec. and then start it again, it does the same thing for abou 30-60sec. And is the same for cold start too.

Things i've done/change:
-idle control cleaning
-ALL vacum/fuel hoses change OEM
-oxigen sensor change BOSCH
-injectors change BOSCH
-AFM change (TO A USED ONE)
-Measured the Ohm of the spark plugs/coils (fine)
-spark plugs changed OEM
-fuel pump changed BOSCH
-fuel filter changed OEM
-carbon filter changer OEM
-prunge valve changed OEM
-DME changed ( TO A USED ONE)
-all fuses changed
-throotle body and intake mainfold cleaned
-throotle position meter chacked (fine)

I know it's a lot of things here been changed, but i had this problem even before having these things changed. After the oxigen sensor it got better but the start up is the same, after the injector and vacum and fuel lines, it got better but the start up is same, after the AFM the idle got fine but the start up is the same( so the idle is crap at start up, but affter 30-60 sec its goes fine ). after cleaning of the idle control it stayed the same.-(if i unplug the idle control while its wants to stall , nothing happens,.. and if i unplug the idle control when "she" runs fine, then the RPM goes up .....to about2000-2500

Idea:automatik Chooke is fucked................BUT i dont know where is that and how its functioning.

-its like this about 8mouths ago and its just the same as since i remember. No white/blue/black smoke from exthaust. And compression is 13-14bar at each cilinder....

Sorry for my shitty english!

Any suggestion is welcome!!!!

Thanks guys

[achtungE30]

Makes 3 members on this board with the same issue. I've also replaced o2 sensor, tried a different used AFM, cleaned out my ICV and old AFM...was thinking about swapping DMEs and ignition switch.

What I do now is just let the car warm up 2 min then drive it and it won't hesitate. Before the o2 replacement, my car hesitated in the upper gears with substantial load. Now it just does this when warming up.

[pepe m42]

it was the DME.
Now, its like new!

[badboypolar]

I had the same problem you both are describing until I replaced the AFM to a new one (rebuilt). It's like a brand new car now.

[achtungE30]

well i just bought (used), AFM, ISV and FPR...we will soon see. I also bought an inline fuel pressure gauge, but since the parts were so cheap, ill just try each one individually to see if it cures the problem...lately its very intermittent, will stumble in 1 out of every 4 starts.

[KenC]

well i just bought (used), AFM, ISV and FPR...we will soon see.

Keep me posted.

Where did you get your AFM?

[achtungE30]

theres a guy on r3v parting out 2 M42s, I'll PM you his sn.

[mlangbauer]

I am having the exact same thing happen. It sputters and spits for the first couple of minutes then smoothes out and runs fine.  

Thanks again for all your help on these cars!!!!!


Matt Langbauer

[badboypolar]

Buy a rebuilt AFM. Used AFM is like putting on used tires. Might last or not.

If you don't want to buy the MAF conversion this is your best bet to correctly repair the problem.

[mlangbauer]

Also, what is a DME?

[badboypolar]

DME is another accronym for the ECM (or ECU).

[mlangbauer]

cool, thanks!