Another m42 Idle issue thread

[smyleboyd]

My car way running like crap, it wouldnt idle unless i revved (alot) it or drove a couple feet. when the car starts driving it sputters (misfires) and tries to die but if i keep it alive by using the gas and clutch,so it would idle. the car would idle but a check engine light would come on at idle. Stomp test gave me 1222 . So i did the "mess under the intake and got done to have the car do the same thing, i tightened up all the hoses and fixed some vacuum leaks and got the car to start up and idle without giving it any gas. the car continued to run fine until i filled up my gas tank. now i cant even drive it. all it wants to do is die. it wont idle at all. stomp test gave me 1251 (Fuel injectors) could it be the fuel pump? fuel pressure regulator? or the fuel injectors themselves?

EDIT: The problem was the fuel pump. I got this pump http ://www.treperformance.com/FuelPumps/TRE255FuelPumps.html#340
Also had my fuel injectors rebuilt and a refurbished afm. Now my m42 behaves how it should

[Quadrajet]

When was the last time the fuel filter was changed? If you suspect the fuel pump, I'd pull the back seat bottom out and listen to see if it's working or straining. If the filter is plugged, usually the pump will be making a high pitched loud whine.

[smyleboyd]

Thanks for the reply. I took out the back seat and fuel pump doesn't sound like its straining. Im replacing the fuel filter right now(which looks very old). The hose going out of the filter was cracked and when i touched it fuel would dribble out. Now i have to find a new hose! I will post as soon as i test it.

[smyleboyd]

Put in the new filter and the car is running!

[Quadrajet]

Exellent! Glad it was something simple.

[smyleboyd]

When i start the car it runs rough but idles, when i push the gas petal slowly the car revs fine but if i push it down more the halfway it misfires an slows down but when i take my foot off the gas it stops running rough . if i rev hard the car will try to die and a check engine light will come on and it will misfire very rapidly in any gear and any speed until l i restart the car. The car does havee oil in2 of the spark plugs so i will do valve cover gasket in the morning.

[goinstrong]

I have the same issue and am told it is the temperature sensor. Replacing that should take car of everything.

Mine runs like it should when it is started when cold. When it is warm, it does what you mentioned. Turning it off, waiting 5 seconds, then starting it again solves the problem. I think the sensor reads it like it is starting cold even when warm and the engine is flooded with fuel...

Hope this helps you.

Tim

[Quadrajet]

Hmmm good to know. I've been fortunate as the only problem I had with one of mine was attributed to bad plug wires.

[2ndName]

What about the vacuum hoses? Check those, supposedly deteriorating hoses can mess with your idle, intermittently.

[smyleboyd]

I replaced all the vacuum hoses already.I havent gotten a chance to work on my car but I think the problem could be the throttle position sensor or the temperature sensor. i will start testing things and replacing things tomorrow (like the plugs, Valve cover gasket, and maybe some wires) i will update as i work on the car

[smyleboyd]

I replaced the valve cover gasket and found oil underneath a spark plug. would that be because of the bad o ring or a bad piston ring. the car wants to idle more after the gaskets but still have the same problem. im about to test some sensors and take off the intake manifold and check for any more leaks. does anybody know how to text the tps sensor or the temperature sensor?

[smyleboyd]

The door on my afm is crooked and not function properly. i feel that s is the problem. does any body have a good used m42 afm for sale? If so then PM me.

[RAYREY]

Oil in spark plugs

I replaced the valve cover gasket and found oil underneath a spark plug. would that be because of the bad o ring or a bad piston ring. the car wants to idle more after the gaskets but still have the same problem. im about to test some sensors and take off the intake manifold and check for any more leaks. does anybody know how to text the tps sensor or the temperature sensor?

i have been reading your post found similar issues with my GQ (Garage Queen) running rough I found water, not oil on no. 3 plugs greenish i know its not window washer fluid coz my is drained I installed a headlight washing system...anyway i cleaned it up dried it up waiting to see how she run after a few hours about tps another member has a write up on how to test tps on this forum too! I see that your from Livermore, I'm in Tracy...

[smyleboyd]

Just to update the thread i got a refurbished AFM from Greg///M. I took out my fuel pump and that thing was so weak it was on its last leg so i replaced it with one from TRE performance. I also had my fuel injectors cleaned from a member on the site MEPEH. Im waiting for the injectors once i get those i will put my car back together and see what happens.

i have been reading your post found similar issues with my GQ (Garage Queen) running rough I found water, not oil on no. 3 plugs greenish i know its not window washer fluid coz my is drained I installed a headlight washing system...anyway i cleaned it up dried it up waiting to see how she run after a few hours about tps another member has a write up on how to test tps on this forum too! I see that your from Livermore, I'm in Tracy...

Thats no good with water in your spark plugs! Maybe its water from when you washed your car? I had oil in mine. you should make sure you didnt blow a head gasket and if you didnt id do the valve cover gasket with the O-rings and see if that helps.
Hopefully you will see me on the road! (if i get my car running) I dont really go to tracy much and if i do its to get trees from the club!

[RAYREY]

Culprit found!!! It was just water from one of the washes!!! It seemed like it has been sitting there for a while (unnoticed) till it damaged plug wire #2 all i had to do is replace #2 and and she's back to normal..

Yup hopefully see you around once you get your car running....Trees from the club! LOL!