xchokex

ok so i did this today this is what i did:

1. unscrew o-ring screws
2. pop that sucka off
3. disconect the wires

ok then i got out the "valvoline synpower carb and choke cleaner" and DOUSED that thang.

of course, gunk just came right off.
and then it looked clean.

i sprayed and shook it up, then sprayed some more, etc. repeat repeat repeat.

before i did this, the idle was really bad and it would die alot.

so i cleaned it out with the carb cleaner and then wiped it up, and reconected it.

of course i then fired it up. it started at 800 rpm or so but then it climbed up to 1200 and then it started climbing to 1600 and then dipping to 1200, etc etc etc.

so now the idle is to high. but!!!!! the power is back!!!! woohoo!!

my question to the hard core q-heads is thus:

did i do anything wrong? and why is she idleing high now? patient is an 86 5ktq

thankx
chris

comp_jas

This topic never seems to go away. I've been doing exactly what you described to my 86 5KCSTQ.

I cleaned mine 2 or 3 times and I'm finally satisfied with the result. Check the ISV temp sensor also.SJM has a picture of the location.

Things I've noticed on mine are:

1)Idles higher if the climate control is on sometimes 300-400 rpm if the outside temp is cold. It was 32F this a.m. Sometimes wanders like you describe but infrequently.

2) If I unplugged the ISV when the idle was high it drops to 800 rpm which to me means that the ISV is being told to control the idle at a higher rpm. Does not imply that the ISV is controlling to the right RPM though. So I kept cleaning.

3) I would think a vacuum leak would make the idle slower (mixture leaner) right? I did find my CO2 test plug was torn open on the bottom. Not sure if that contributes much or not.

4) After reading about the system I/m still not sure how many inputs the CIS monitors to decide what the idle should be. Is it just coolant temperature or does it use air temp as well?

xchokex

where is the temp sensor?

my saab-vw mechanic says that the idle should be 'set' now. but how would that be done?

otherwise car is boosting well....BUT

when i first start it it takes a long time to get going..... sometimes it jumps to 2000 or 3000 rpm....but a quick tap of the gas fixes that.

TIA
chris

comp_jas

sjmautotechnik.com has nice photos of all the sensor locations as well as values in ohms. Facing the car, the sensor is near the front of the engine on the right. Three sensors (ISV, multi-function and ECU) are within inches of each other where a coolant hose exits the engine block. I'm typing this from memory.

DaveN

it is one of the two switches in the housing on the throttle body. The connector to this switch likes to go bad also, all that bending on that short path from the intercooler.