Really low idle and running rich

[skimdilk]

Hey all, I searched best I can but I'm stumped on this issue with my 88 lxi 5spd.

After the car is warmed up and I pull up to a stop the idle will drop as low as 400-450, this is accompanied by vibration (though I'm hesitant to blame the motor mounts as they were replaced roughly a year before I bought the car). My car is also running very rich with my exhaust smelling like straight spilled gasoline, not sure if this is normal. One last detail, sometimes as the idle drops it is sometimes accompanied by a bump that seems to be in time with one of the cylinders. When I say bump I don't mean a knock, just like when you suck something solid through a straw and it *pops* through.

I've put some Fuel system cleaner on my last fill up and have started using 89 octane gasoline, it seems to help but I feel like its just a band aid.

Any pointers would be appreciated, my old 3g lude did something like this and I never quite figured it out. I'll also add that there is no loss of power and anyone who says you can't scoot around with a 4cylinder sohc engine is full of sh*t, she feels fine when in motion ;>

[Oldblueaccord]

You can look at the ECU under the drivers seat and see if there is a error code. There is a sticky on it in the EFI section.

Fuel injection it should n0t be running so rich you smell gas.

[87rustbucket]

I have no idea if this could be but could one of your cylinders be dead, no spark.

[skimdilk]

I have no idea if this could be but could one of your cylinders be dead, no spark.

I've driven cars where this has happened and in my experience its way worse than what I am experiencing. However maybe it only happens at idle? I'm not sure, I wonder if this isn't somehow an electrical issue. I know my alternator is not functioning at full capacity so that may be the problem


You can look at the ECU under the drivers seat and see if there is a error code. There is a sticky on it in the EFI section.

Fuel injection it should n0t be running so rich you smell gas.

Just checked it and it wasn't throwing any codes, maybe my ECU is faulty? But I'm guessing it would be running a lot worse if that were the case, it's only noticeable at stops.

[5 Speed Speeder]

you can adjust the idle screw and see if it changes anything. it's on the throttle body right above where the intake U meets the throttlebody. turn the screw counterclockwise with a flathead screwdriver to raise the idle

[Dr_Snooz]

Leaky injector?

[skimdilk]

Leaky injector?

Possibly, hopefully I will be getting a job at a shop that rebuilds diesel engines soon. I was told that if I start working I will be able to use the shop for my own rebuilds ;> Its frustrating that this problem is so minor but so difficult for me to diagnose. Thanks for you help.

[Oldblueaccord]

Possibly, hopefully I will be getting a job at a shop that rebuilds diesel engines soon. I was told that if I start working I will be able to use the shop for my own rebuilds ;> Its frustrating that this problem is so minor but so difficult for me to diagnose. Thanks for you help.


Your fuel mileage must be terrible I would guess.

Try unhooking the battery for a few mintute to reset the ECU anyway and see if that helps.