Hybrid96EK

This isn't like most idle issues you read about. Here are some details. Freshly built B17. New pistons, rings, gaskets, etc. When the car is first fired up, the fast idle shoots up REAL high, like 4,000rpms or so, then drops down after about 2 seconds. It holds fairly high and doesn't seem to gradually drop down like it should, but eventually winds up around 1,000rpms. Here is where things get interesting. The idle will sometimes, not always (but most of the time) bounce from 1,000rpms to around 1,300rpms. Really small fluctuation. Sometimes, without doing anything, it goes away and holds 1,100rpms... Then comes back, again without doing anything. I have changed the intake manifold gasket thinking it was a vacuum leak. Same results. Put a whole other intake manifold on it also, same results. Checked all vacuum lines, they look fine. Far as I know, all smog equipment is hooked up, all lines are run correctly. I have also tried 4 different IACV's, same results. Tried a stock P61, same results. Tried spraying carb cleaner around everything, no change in idle. Installed a completely different TB, same result. Changed the MAP sensor, same result. Its driving me insane. Does anyone have ANY suggestions that I have not already covered?

Edit: Some more interesting facts. If I drive the car, when you push in the clutch as in to come to a stop, the idle sits high... Say 2,000rpms... When I come to a *complete* stop, it will drop down to 1,100rpms, but never unless I come to a complete and entire stop. Make any sense?

poison

damn. You've covered a lot of the issues for having a decent idle.

I would recommend you adjust the fast idle valve diaphram underneath the TB, and also make sure there is NO air bubbles in the water system.

burp the system, and clean the fast idle valve. also make sure your MAP sensor readings are good as well (having good vacuum and clean). At times, the MAP sensor will not throw a code, but has shitty vacuum readings and makes the car idle like ****.

HTH.

Hybrid96EK

The map sensor has been replaced, the hose to it has been replaced as well with a brand new one. The system has been bled several times. The current intake manifold does have a FAIV, but the other intake manifold I was using did not. Keep in mind I had the problem with both manifolds..

Something else to add to the fire here..


This engine is sitting at about 11.0-11.5:1 compression. I am in cali, so I am using 91 octane. I failed the 15mph emissions test, NO was out the roof. Its fine at 25mph. My understanding is NO = cylinder temps are too high. I checked the coolant temp sensor and get 176ohms. Its supposed to show 200-400 when up to temp. This again tells me my car is running hot. On the dyno, I didn't see any signs of detonation and when I dynoed, it was 95 degrees. I run a Del Sol dual core radiator and a brand new Napa special thermostat. I am pretty sure, but not 100% that it is the correct stat. I noticed today the fan was coming on a lot while I took my readings and the car was idling... Temp was around 85-90. I fear the pistons might be too much.

If anyone who reads this has a high comp engine, would you mind taking the OHM reading off the coolant temp sensor on your head for me? I would be interested in seeing what temps you are showing.