Mustang5090

Hey guys hows it going, recently been having an issue with my car, when i start it in the morning sometimes it drops to a really low idle and stalls, as soon as its warmed up its fine but than when i stop at a light and have it in neutral or the clutch in the revs jump to 1500 or soo and than hanger there than drop to 1000 and than to the normal idle i have set around 800, its a 90 lx 5.0 with a t5 conversion, ive cleaned the maf, ive changed the iac, brand new tpms sensor, all plugs wires cap rotor are recently new, just trying to narrow it down cause im not too sure what it is, hope you can help and let me know if you need anymore info on the car

AdderMk2

you need to do a proper base idle reset, and check that your TPS is within the proper range.

.99v is wrong. Try to keep it between .8v and .9v

Mustang5090

hey adder do you have a good write up url on a proper reset? cause ive done it before with no results, and i just wanna make sure im doing it correctly

scottybaccus

I have one that has a lot of carbon build up in the intake. I had to change the EGR because it was just too fouled to be reliable. Now with the new EGR installed, I still get an issue once in a while where the idle goes way up an hangs there, or even stalling because of a bad vacuum leak. What's happening is pieces of carbon are coming loose in the EGR passages and getting drawn into the pintle of the EGR valve. If luck plays dirty, the debris prevents the valve from closing when I take my foot off the gas, keeping the EGR open. In a minor case, this is just enough of a vacuum leak to raise the idle a bit and it usually is pretty rough since it's exhaust gases with unpredictable amounts of oxygen. In a bad case, the debris is so big it creates a huge vacuum leak, stalling the engine at idle. Putting my foot on the gas raises engine rpm enough to dilute the leak, masking the issue, and it also opens the valve, usually dislodging the debris. Then my normal idle returns and I have no clue what just happened.

Message: If you have some miles on your car and the EGR is still there, it may be your very frustrating and highly variable issue. This might throw an EGR code, but not always.

wydopnthrtl

I too would like to know the proper procedure for a 5.0L.




For a OBD2 ford its:
- Clear the KAM (battery disconnect, lights on, lights off, reconnect battery)
- Let idle up to proper operating temp
- AC on for at least 30seconds
- AC off for at least 30seconds
- AC on & automatic transmissions in gear for at least 30seconds
- AC off & automatic transmissions in gear for at least 30seconds

The key is to get it up to full operating temp. Also, this is just a quick way of making it learn. If you don't do anything.. in time it will hit each of those situation and re-learn.

Regards,
Rich

AdderMk2

That doesnt help at all, because his car is NOT OBD2! You seriously need to do more research before you keep posting.

OP, google Mustang Base Idle Relearn.

The part where it says to "set the idle to the RPM you'd like"... Don't do that. Set the RPM's to about 650-675 RPM with the IAC disconnected.

wydopnthrtl

You "seriously" need to **read** what I wrote. Instead of jumping down other peoples throat in nearly every post, have some love for your fellow man.

Look, this is a car forum. I'd suggest to you that most of the readers here drive OBD2 cars on a daily basis. Learning about cars.. all cars doesn't stop just because your on one forum or another. Have you ever gained knowedge from one forum that helped you on another model of car??? We all have!
I have a wealth of knowledge about cars. Depths to which will never be known by most.

Yes I'm out of tune with pre-96 models. But having car related knowledge and sharing it is important to me.

Chill out and help others instead of throwing around insults. Love is the first and greatest command. Look it up.

Regards,
Rich