95 Q45 engines stumbles after hot soak

[3Q Jay]

tps would need to be way further off to throw a code. like 0V or 5V, and pretty much in between will 'pass' the idiot lite.

0.40 hot idle (important!!) should be close.0.44V is the preferred NICO setting, but it's sometimes hard to dial in exactly.

AAC setting is fine.did we establish your timing?

[GseaQ]

Thanks Jay. The timing was set by a light to 15* BTDC (I think) months ago. I will have to check it again, but the NDS shows it fluctuating from 45*-48* and, if I recall, we have to subtract 30* from that. It spends most of it's time at 45* or very close to it.

I don't think I'll mess with the TPS looking for the other 0.04 volts. The 0.40 was a hot idle. I didn't even plug in the consult cable until it was hot and all readings were at 88*-92* C.

I'll keep you posted. I really appreciate all the feedback from you guys.

Glenn

[Q451990]

Remember that the timing number you see with any of the consult software (or Consult) is what the ECU is trying to do... not always what's actually happening. In other words it's the target, but to know what's actually happening you have to look at the timing with a timing light.

Heath

[Q45tech]

The 15 BTDC is nothing other than the ASSUMED number. The CAS is the master clock for ecu and ecu always assumes it is set correctly at 15.

The point is unless the CAS is set correctly the Consult numbers will never be correct...............unlike OBD2 there is no ZERO back up to check the intial timing............the timing light is KING.

The other problem is chain stretch in that CAS references the exhaust cam on driverside so the banks can be off 1-2 degrees with age from each other and the crank especially in acceleration vs deceleration.

[GseaQ]

Thanks Dennis. I'll get the timing dhecked/adjusted with a light this week sometime. Today is out as we're getting a copious amount of our famous liquid sunshine!

BTW, can you tell me which wire to hook the timing light pickup on? The old '92 had an ignition box on each valve cover and we used a wire from it, but the '95 doesn't have those boxes.

Thanks,Glenn

[3Q Jay]

look at the (search for) the 'method B' post (search post titles, can't remember if it was the Q45 forum or IoM).

[GseaQ]

Thanks, Jay. Method B it is. After doing the search you suggested and reading the only resulting thread, I went through the FSM. Sure enough, page EF & EC 34 has the details.

Cheers,Glenn

[GseaQ]

So, update.

I did put the timing light on it. It's set at 15-16* BTDC, so the 45* shown by NDS is right.

IAC is still right as I set it last summer/fall.

The MAF was fine after the "re-soldering" until about a month ago. Then it started doing the same old stumbling thing. I took it off again and re-soldered it again, but this time I added some new solder to the contacts. Seems to be like new again.