bdazzler

At wit's end with this thing. I'm going to attach a video link, if anyone wants to give an opinion. Getting error codes 24 (intake air temp. sensor signal) and 31 (air flow meter signal). Things I've done of late:

• Changed rotors & distributor caps
• Changed spark plug wires
• Changed oxygen sensors (had them wired incorrectly but good now)
• Changed engine coolant temperature sensor
• Changed thermostat
• Changed coil packs and spark plugs about 6 months ago
• Did an ECU exchange about two years ago (but maybe the problem?)

I did the test to check the MAF, unplugged it but still ran w/out it as you will see in the video. Also changed it to one I bought online about a year ago. No change with the two. Undid the vacuum line to see if the IAC is stuck or not, got air suction so don't think that's the issue.


Any opinions are highly appreciated!

dicer

How many miles ? How much do you want to spend?

djamps

Assuming you've got a good MAF, I'm guessing it's wiring or ECM related. Air temp signal and air flow signal come from the same sensor (MAF) and harness (usually, at least... not 100% sure about the LS) and are probably passed thru the same part of the ECM's circuits, so either a bad harness or maybe a cap has leaked and broken some traces in the ECM. I'd start by testing the wires going to the MAF and make sure there's good power and ground, then test for continuity to the ECM. Follow thru with a ripple test as explained in the big ECM thread.

djamps

And FYI at least on my 98 if I unplug the MAF like that it immediately dies. After restarting it it's in a 'fail safe' mode with some kind of pre-programmed MAF assumption and runs like crap, I assume yours is in that mode.

bdazzler

A bit over 150K. Not a lot to be honest. Got any ideas?

bdazzler

Thanks! I have a feeling this might be ECM related as well. That the company I used to rebuild the caps didn't do the right thing, i.e. used the right capacitors.

bdazzler

I took off the fan shroud, didn't realize it before but it had some small cracks in it which caused the fan to slightly hit it. So the video above is new without the annoying clicking sound which resembled a sticky valve noise.

dicer

And like I said in the PM its difficult to sit at a PC and troubleshoot. It sounds like a vacuum leak, though I'm not there to know for sure, I kinda hear it, I think.

IzzyFlexus

did you ever get it figured out, having the same problems and throwing the same codes

bdazzler

Sorry for late reply...guess I didn't notice the email was for this thread....it was the ECM. The clowns who rebuilt it was useless. Be careful who you use for that.