Rough idle

PR8urvtec · Post by **PR8urvtec** » Wed Nov 18, 2009 3:55 pm

Hello,

I just put my LS motor in a crx and I am having some issues. I put a stock LS tune on the ECU. I have RC 310cc injectors. I went to OBD1 obviously and the injectors are saturated. The motor only idles rough before it's warn. I don't think I have a vacuum leak. I did a datalog just to see if anyone could find something.

I went to the fuel trim setup under parameters and put the new injector size in the box. Is there anything else that I need to do? I didn't change the fuel pressure at all.

I have two check engine codes. One is the water tempeture sensor. I am going to change that out. The other is electrical load detector. I have read this could be alternator problems as well.

Any help would be appreciated.

Post by **Spunkster** » Wed Nov 18, 2009 4:37 pm

You need to fix what is causing the error codes and then get it properly tuned.

ELD may need to be disabled if the car never originally had an ELD.

BLKACK1 · Post by **BLKACK1** » Wed Nov 18, 2009 4:52 pm

What year crx, chances are there is not a ELD present in the car so just disable it in the smanager program

PR8urvtec · Post by **PR8urvtec** » Wed Nov 18, 2009 5:01 pm

It's a 89 crx HF.

BLKACK1 · Post by **BLKACK1** » Wed Nov 18, 2009 5:39 pm

Are you using a P28 ecu? just disable it and fix your other code and you should be good on that issue

PR8urvtec · Post by **PR8urvtec** » Wed Nov 18, 2009 5:44 pm

No I am using an LS ECU. Thats what I did. The car is idling high though until warm it levels out. Now I just have the water temp sensor. Would throw my idle off? I know it uses coolant to open valves at the throttle body but im not sure if the CEL is causing the idle or the injectors.

OSracer · Post by **OSracer** » Wed Nov 18, 2009 8:21 pm

ECT Water temp helps the Idle Air control valve to adjust the amount of air bypassed around the throttle body until the engine warms up as it does that the IACV starts to close up and the fuel leans out as you run rich during warm up.

colder the car temp the more fuel is dumped and idle is controlled. Hence possible reason why you idle rough how rich does the car run? Im running into the same problem only opposite my IACV is stuck open and cold idle is fine then I run lean when warm. With a surging idle at 120 degrees F or higher... from the coolant temp.

Anyone got a IACV? cant get to the junkyard till next week !:(

PR8urvtec · Post by **PR8urvtec** » Fri Nov 20, 2009 5:08 am

Thanks. The previous shop just used but clamps to hold the sensor together. I must have missed it but I soldered everything up and it works find now with no codes.

I have another problem though. It's seems like my car wants to idle high when I am in closed loop and when I go to open loop it sits at 1000rpm fine. It is a stock engine with a stock tune. The only thing I have upgraded was the injectors to 310cc from stock. I thought maybe a vacumm leak but I checked everything. Any ideas?

Thanks,
Ryan