Full Version: 74 1.8l L-Jet Question
So I have this annoying problem after about twenty minutes of driving my car. The first twenty minutes it idles at around 900rpm and after warm up it drops off to around 100 or less. A lot of the time the engine idles so low that the car dies. It always starts back up but it's a pain to try to manually idle at every stop light. Some research I've done proposed it could be a head temperature sensor gone bad. Could this be the case? Any help would be appreciated. Thanks, Eric
I had a similiar problem. After a hard excel the car died when I came to a stop. I could only start it if I kept the pedal down (manual idle). This happened twice.
I found the air vane in the Air Flow Sensor was sticking at a higher than idle setting. A tap with the knuckles loosened it.
I eventually took it out and cleaned up the inner chamber (without disassembly) with steel wool to knock off any surface corrosion.
No problems since. Hope that helped.
I found the air vane in the Air Flow Sensor was sticking at a higher than idle setting. A tap with the knuckles loosened it.
I eventually took it out and cleaned up the inner chamber (without disassembly) with steel wool to knock off any surface corrosion.
No problems since. Hope that helped.
you can measure the resistance of the head temp sensor to check if it's bad. upon warm-up, the car should idle higher than warmed up idle. you might up your hot idle speed, should be about 900 rpm.
As a 1.8 L-Jet owner, I've been down this same road. There are several possibilities. Fist thing is to make sure all those hoses that connect to the plenum, throttle body boot, and oil filler are not giving up any vacumm. Check the Pelican Hose diagram and make sure the hoses are correctly attached.
QUOTE(jim_hoyland @ Jul 26 2008, 09:08 PM) 
As a 1.8 L-Jet owner, I've been down this same road. There are several possibilities. Fist thing is to make sure all those hoses that connect to the plenum, throttle body boot, and oil filler are not giving up any vacumm. Check the Pelican Hose diagram and make sure the hoses are correctly attached.
And also check the oil filler cap (NO, I am not smoking anything). There are 2 seals on the oil filler cap, and if either of them are bad, the car will suck air around them and it won't idle. There is a big, flat rubber seal, and an O-ring.
The problem with vacumm leaks is they can be difficult to detect. I finally installed a vacumm gauge in line with one of the small hoses going to the plenum. It's mounted in the engine compartment where the targa top holder nuts are.
As you tweek or replace hoses, you can see whether the vac changes. When you get it running right, you will have a reference vac for future issues.
As you tweek or replace hoses, you can see whether the vac changes. When you get it running right, you will have a reference vac for future issues.
I would agree with everything above.
The two overlooked vacuum leaks (aside from the hoses and oil cap)
Injector seals
Poorly adjusted valves.
Rich
The two overlooked vacuum leaks (aside from the hoses and oil cap)
Injector seals
Poorly adjusted valves.
Rich
Well, it looks like I have a little work ahead of me. I do appreciate your input. Eric
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