Hi Folks, I feel like a complete n00b for posting this, but I havn't seen any posts directly related... I'v recenty been having trouble setting my idle. Just to get it out of the way, this is what I do:
Warm up completely, blip throttle a few times, let idle for a min.Shut off, disconnect TPSStart, adjust timing.
Now, this is the first place I run into trouble. My timing oscillates back and forth, by about 1-2*. It advances for about 1.75sec, then retards for like 0.75sec's. I set the timing at roughly 19* TDC to be safe. My idle is also raising/lowering just enough to see it on the tach, and hear it in the engine bay. If I lower the base idle even more, the oscillations seem to get wider(more advanced/retarded)
I set the idle to 900rpm, shut the car off, and reconnect my TPS.
Now my idle is solid, but it dips to 5-600 on decelleration(closed throttle), and with heavy alternator loads(ie power window limits, etc). It also dips down 100rpm with heavy braking at idle.
I really don't understand why my idle/timing oscillates in base-map mode. Shouldn't the ECU relinquish control over the AAC valve? This is just a hunch, but I'm pretty sure my timing fluxuating is just the result of my oscillating idle. FWIW the ECM shouldn't be advancing/retarding timing either.
This was even after I ran 1/2 can of seafoam through the intake.
I have gone over every single one of my vac connections and seals with tons of carb cleaner, I can't find any sort of leak.
Any thoughts?
1992 240sx trouble setting idle
Re: (180fan)
No I haven't considered that. My idle is really pissed off now after that seafoam. When I started it for lunch, the idle bobbled up and down around 1-2k, and ran like crap. I'm going to look at the MAF after work tonight, because that's the only other thing that might be making it act up.
I'm buying an IACV to dissasemble and inspect before I install it also. I just hope it isn't the FICD, that's the one that's a PITA to get to...
Cheers,Jamie
I'm buying an IACV to dissasemble and inspect before I install it also. I just hope it isn't the FICD, that's the one that's a PITA to get to...
Cheers,Jamie
Re: (slipnfall)
Ok well some good news, I fixed my crazy idle. I had an intermittent connection on the ground side of the TPS connector, thus bumping my idle up/down.
Second was my base timing. This might not make sense, but setting the idle via disconnecting the TPS and using the CONSULT interface did NOT yield the same results! Bear with me here: if I set my idle/timing using the TPS, I had to screw the idle adjust in pretty far. My AAC valve control value was ~40 in this 'base' mode.
Now, when I tried to use the CONSULT interface to do my idle, I couldn't even start the car!!! I backed the idle screw out, and tried again. This time I adjusted the screw out to give me a proper 750rpm. Also my timing did not oscillate as it would when using the TPS. Now in base mode my AAC control value is around way lower, like 8. Also I noticed my timing was now about 4-5* retarded.
Car run beautifully now... I don't understand the difference between the two idle/timing adjust modes, but the TPS method didn't seem to work right.
Jamie
Second was my base timing. This might not make sense, but setting the idle via disconnecting the TPS and using the CONSULT interface did NOT yield the same results! Bear with me here: if I set my idle/timing using the TPS, I had to screw the idle adjust in pretty far. My AAC valve control value was ~40 in this 'base' mode.
Now, when I tried to use the CONSULT interface to do my idle, I couldn't even start the car!!! I backed the idle screw out, and tried again. This time I adjusted the screw out to give me a proper 750rpm. Also my timing did not oscillate as it would when using the TPS. Now in base mode my AAC control value is around way lower, like 8. Also I noticed my timing was now about 4-5* retarded.
Car run beautifully now... I don't understand the difference between the two idle/timing adjust modes, but the TPS method didn't seem to work right.
Jamie