'98 Olds 3800, tries to die at idle, no MIL

Ours was an '87 Celebrity wagon 2.5 Iron Duke/Tech 4. It did the same thing, first it wouldn't restart hot but was OK if left running then it started dying. The shop fixed it and part of the fix was a new TBI fuel injector, some time later it would start, run for a few seconds, and die. If the alternator was unplugged it would run flawlessly so I hooked up a battery charger and noted that when the voltage went above 14 it would die, It turned out that the new injector was defective and was shorting out under load and tripping the ECM's protection circuit (it ohmed out fine). I confirmed this by hooking a resistor in series with the injector and noted that the engine stayed running at full operating voltage with the alternator plugged back in. I had the new injector replaced under the 1 year warranty and it ran fine again.

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The 3.1 LIM is harder to do than the 3800. Just more crap to move out> of the way.

Thanks for the tool tip, I may need it as I have 2 OBDII Luminas with the

3100, a '96 LS with Cal. emissions and the aforementioned '97 base Fed. emissions. Both have bad turn signal switches currently and the '96 has bad tires. Why can't all cars have separated stop and turn lamps like my GF's '91 Tracker 4x4?

FWIW I now understand the sentiments of those who say that they will never buy another automatic trans car, I put a newer engine (a '94) in the Tracker and it is the first manual trans car I have ever driven and I already love it, granted I have been driving farm tractors for a couple years now and can rev match shift some of them without the clutch, but I didn't think driving a manual without an engine governor could be so easy or fun. I haven't killed it yet but she killed it twice in a row when she forgot to release the hand brake LOL.

Reply to
Daniel who wants to know
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I bought a Delco crankshaft position sensor and went to change it out, but decided I wouldn't be able to get the harmonic balancer off, as my puller probably wouldn't fit right to pull it. Figuring that the labor wouldn't be that much with the correct puller, I took it to the GM dealer (I was right -- an hour labor to change.) They said they would rather diagnose it themselves to ensure they weren't changing the part that didn't need it, and I gave them the go-ahead. They diagnosed it using a tech 2 and said everything points to the MAF. My Innova scanner said the same thing.

HOWEVER, after MY scanner had indicated the MAf, I unplugged the MAF, and the engine still cut out, flared, etc. aferwards. I n other words, it exhibited the exact same problem in open loop without the MAF even in the equation.

SO... Should I just have them change out the Crankshaft Position Sensor, like I originally was going to have them do anyway ( since it has 175K on it and is probably due -- plus the engine dies ect. without the MAF plugged in, thus indicating something other than the MAF)?

OR... just change the MAF myself, which costs $200 and might not change the problem?

In other words, if scanning it with both my Innova, AND a Tech II by a pro, and they both indicate the MAF -- but the engine still acts up without the MAF even plugged in... What would you do?

Reply to
blowout preventer

I would change the MAF!

Why? Because if you unplug it and NOTHING changes then it isn't working.

Reply to
Steve W.

I second Steve's opinion. Change the maf. If maf is plugged or unplugged and it does the same thing, then that means its not working at all. Especially after two scanners say the same thing.

Reply to
Paul in Houston TX

"blowout preventer" wrote

I'd expect that if it was not working.

If your TV, toaster, or washing machine don't work, do they act differently if you unplug them? If not, you'd have to assume what?

Reply to
Ed Pawlowski

Yep, there is the correct diagnosis, and three cheers for the dealer who suggested more diagnostics were in order before replacing parts that may not fix the problem.

Reply to
PeterD

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