high idle problems
 

Ok, my car (85 TA LG4 M5) had been idling high (~1500-1750 rpm) since i bought it last summer. I tuned it up (replaced all plugs, wires, new dist cap/rotor, oil change, all filters, new EGR valve, new O2 sensor), and the problem was still there. I replaced the carburetor with a newly rebuilt one, and still had that problem, despite making adjustments to my fast and curb idle screws.

Last weekend, I replaced the choke heater relay, after reading another thread on the boards about someone with a similar problem. This worked, and the idle went down to normal (~700-750 rpm) and was able to drive it around without problems other than the fast idle being a bit low when I started it. Today, I readjusted my fast idle and curb idle to spec, and the TA idled perfectly fine for several minutes, and then it went back to its old high idle of ~1500 rpm. :doh:

One thing I have noticed since I got the car is the oil pressure guage doesn't seem to work properly. It's always maxed out. I can only recall one time when it did work correctly, and then my choke heater fuse blew. Could the high idle be related to a problem in the oil pressure wiring?

I'm convinced that the root of my problem is somewhere in the electrical system - I'm thinking something to do with the oil pressure sender. All input would be greatly appreciated.

The oil pressure sender won't have a switch unless there was an in-tank electric fuel pump installed sometime after it left the factory. Even then, it shouldn't have anything to do with the choke circuit.

I agree it sounds like you've got an electrical circuit issue. Have you verified the voltage at the choke?

Re: high idle problems
 

No, but I have observed the choke butterflying opening from completely shut to completely vertical on cold starts. I can borrow a voltmeter though.

Whats weird is that the oil pressure guage actually worked one day a few months ago, and I didn't seem to have the idle problems that particular day. Could be coincidence, but I just thought I'd point that out. Sorry, I meant sender not switch in my 1st post.

Re: high idle problems
 

The oil pressure sender only operates the gauge. It has nothing to do with anything else, so it's unlikely to be related to your problem.

Re: high idle problems
 

ok, i'm gonna check out the wiring going to the choke heater relay, maybe somethings loose.

although unrelated to the problem, i'm guessing i need to replace my oil pressure sender unit, so my guage will function properly.

thanks for the replies.

Re: high idle problems
 

i noticed that the part number of the ch. heater relay i pulled off is "14039662", and the one i put on is "14089568".

i looked on gmpartsdirect.com, and the original part no. is not valid. does anyone know if the one i put on, "14089568" is the right one? according to the parts tech at the local dealer, it's the one, but i just want to verify...

also, is there any way i can check to that the relay works or not? i haven't been able to work on the ta lately because its been raining pretty bad where i live, but it's a sunny weekend coming out, and i might work on the car.

Re: high idle problems
 

I finally got a multimeter and was able to check this. My voltage at the choke is about 13.5 V, and the resistance is ~6 ohms. This is normal correct?

Re: high idle problems
 

I finally got a multimeter and was able to check this. My voltage at the choke is about 13.5 V, and the resistance is ~6 ohms. This is normal correct?