I've got a list of random things wrong with my car.....haha It was running an obd1 single cam civic ecu, when i put in a gsr ecu it threw check engine code, for intake temp sensor, and crank position sensor....well turns out my timing was also off a few degrees, so we fixed that, cleaned up the sensors and put the gsr ecu back in. Throws the check engine, now for the knock sensor.

Any who here are the two big things my car does and any ideas as to why will rock.

When i first start it, if its cold out especially, it just dies, I need to keep it revved to about 2k for 5-10 mins or it just dies.

After I drive it a while the idle bounces from 1k down to almost dying, that may be an idle control valve, but I'm not sure what'd cause the first issue.

Both things happen with either ecu.

I should be pulling the whole motor here soon to just fix everything( it's also got a hacked wiring harness and they kinda just half assed the motor install it seems) But until then if any one can help me with any ideas towrads why it's doing it would be great

Thanks
Nat

 

as fas as your idle goes i would adjust the idle control valve. are your cams lobing after the car is warmed up for the 5 to 10mins?

 

Do you have an aftermarket ignition set up? My 98 gsr dis that when my distributor cap/rotor was falty.

 

You can start with cleaning your IACV (Idle Air Control Valve). You can use carb & choke cleaner, or brake parts cleaner. Why is your harness hacked up? Was the motor swapped in?

Is there anything done to your engine internally, that requires a tunable ecu?

 

Are you looking to replace the fucked up wire harness too? You could have some shorts or some intermittent signal sending issues.

 

Everything is stock as far as I know, and actually the only thing I didn't replace when I first did a tune up when i first got it was the distributor cuz she gave me the wrong one at the parts store.

And He blew the old motor he told me so he had this one put in by a shop here in portland, but I don't believe that after seeing it. And I dunno why it's hacked up, I think it may have been an ls harness that he wired to use or something?


also- what do you mean by the cams lobing? I also didn't know you can adjust the idle control valve I thought u just had to replace them when they went bad- if it's not too much trouble could someone hint towards how one would do that?

 

Remove the IACV, and spray the inside of it with brake parts cleaner. Let it dry out, and replace. Brake Parts Cleaner evaporates rather quickly, so it shouldn't take long.

To set the idle:
Remove the wire clip from the IACV, on the back of the Intake Manifold.
Remove the EVAP Purge Sel. Connector, Next to the MAP sensor on the TB.
Start the car, and hold the accelerator at 1500 - 2000 RPM's (It will throw a CEL)
When the engine is warm, slowly let off the gas and allow the RPM's to stabilize.
There is a flat-head screw on the Throttle Body, facing the Fuse Box. It might be covered in a silicon type material, just scrape it away and adjust the idle in 1\4 turn increments. Use the VECI labe under the hood to find the proper idle speed. For me, its 750 +/- 50 rpm's.

When you get it set correctly, shut the car off and replace all electrical connectors. Then remove the 7.5 amp fuse from the fuse box under the hood, for a minute or so. Replace, and start the car.

This is also a good time to make sure your ignition timing is set correctly. Good luck!

 

Wow thanks a ton that was super helpful- I'm gonna have to try that tomoro when I'm off.

 

Heres a link to download the factory service manual. Its a big file, but save it on your computer. Should answer every question you have.
http://tech.hybridgarage.com/tech/ma...e%20manual.pdf

 

The IACV might be fine, it could be you fast idle thermo valve. forget exactly what its called but its close to that. I think it is on the front of the throttle body, it easy to find because it has coolant tubes running to it.

You probably know this but there are two valves that bypass the the throttle plate to allow the motor to still get air. the IACV is controlled by the ECU the other one is mechanical; it is supposed to be open when the coolant is cold, but im not sure if it completely closes when its warm.

the best way to diagnose idle valve issues is to pull off the the intake to where you can see the two holes for the two valves. you can just stick you finger in them one at a time while the engine is running and see if it affects the idle. If blocking one off has no effect that valve is not working.

your idle is surging so that is ECU trying to stabalize the idle so your IACV is somewhat functional.

usually if your idle is off, it is for a reason, adjusting the throttle plate just covers the underlying problem, although if your motor has been swapped that could just be the problem.

If the idle valve seems OK It could also be your PCV valve

Im not sure about the knock sensor, except I think it has a green plug.