92 Cutlass Ciera cold idle problem

Hi all: I've got a 92 Cutlass Ciera that, since undergoing a recent major tune-up, has been exhibiting a cold idle problem described as follows: About a minute, or so, after a cold start, when the initially rapid cold-idle speed normally ratchets back to warm-idle speed, the engine starts to sputter and then dies. If the engine is forced, with the accelerator pedal, to idle at a slightly higher speed for another minute, or so, the problem disappears and the engine will then slow-idle normally. If the car has been operating normally and is then parked with the engine shut off for an hour or so. the same problem is experienced immediately on restart. In all other respects the car seems to be running perfectly normally and no other problems are noted. So the problem seems to appear only within a very narrow range of relatively low operating temperatures, but the GM dealership that did the tune-up has so-far been unable to isolate the cause of the problem. Any suggestions re. possible/probable casuse(s) of problem described above would be greatly appreciated. Thanks for your replies!

Reply to
pe
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What kind of engine is in a 92 Cutlass Cierra? Do the usual: gap plugs (did they do that during the tune up?)

The rest is not normally done during a tune up: check wires when hot clean and check: tps, egr (none on 3.3), iac, maf look for vac leaks at intake/head surfaces, hoses, etc. clean throttle body

Reply to
=?x-user-defined?Q?=AB?= Paul

Reply to
Shep

It's the v-6 with front wheel drive. I'm not an auto tech expert, but it seems to me, logically, that if the problem was attributable to any of the causes you suggest (vacuum leak, etc.), then I'd notice rough running at all engine speeds and temps, whereas, as noted in my message, it happens only at idle and within a narrow range of low operating temps. What am I missing?

Reply to
PE

You still have not told us which engine. They are NOT all the same. Everything we said applies mostly to cold engines, not hot. Your logic is ... illogical.

With very few exceptions, things expand when they get hot. They shrink when they get cold.

Shep: "scan it and check for proper coolant temp sensor readings." Are those readings within spec for all temperatures? A bad sensor sends the wrong signal to the ecu. Me: check wires when hot: what are the ohm readings? High ohms are an indication the wires are bad. Bad wires often leak when cold and damp. Is it damp in your part of the world in the mornings?

EGR: Could be clogged partially open. However, without knowing what engine is in your car any discussion about that is a waste of time. TPS: could have a worn spot at the idle position. What are the ohms/volts readings? IAC: could be clogged or worn out so that it does not allow the right amount of bypass air into the intake. MAF: could be covered in carbon gunk. Carbon gunk makes a good insulator. MAF thinks its some other temp than it really is and feeds bad data to ecu. VAC and coolant leaks: mating surfaces contract when cold and may not seal well. When things get hot they expand and seal holes. Applies to hoses as well. THROTTLE BODY: carbon gunk holds the TB partially open allowing more air then the engine's other sensors say. Ecu does not know what to do. If your O2 sensor is original, it is shot and sending the wrong signal to the ecu.

It sounds like your car may be in need of basic maintenance.

Reply to
=?x-user-defined?Q?=AB?= Paul

Paul, thanks for the elaborate response. I see your point! Where would I find the information that would adequately identify the engine?

Reply to
pe

Check for a sticker in the engine compartment, or a number on the intake.=

Its got to be a 3.3 or 3.1 but I'm not sure which is in that model. They are really different engines and look quite different. The 3.3 looks very similar to the 3.8.

Reply to
=?x-user-defined?Q?=AB?= Paul

Pop the hood, and look at the engine. It usually will say what it is. From what I can find, an Oldsmobile Cutlass Ciera "SL" Model would have the 3.3L V6, whereas the "S" Model would have the 2.5L 4 cylinder.

Reply to
80 Knight

It's a Ciera SL, and it's got the 3.3L V6 fuel injected engine.

Check for a sticker in the engine compartment, or a number on the intake. Its got to be a 3.3 or 3.1 but I'm not sure which is in that model. They are really different engines and look quite different. The 3.3 looks very similar to the 3.8.

Reply to
PE

Ok. The maf is on the side of the throttle body. Look for gunk on the thermistor and cracks on the case. Careful - it is fragile. There is no egr. Torque down the intake. I forgot what the in/lbs are. Its in a Chiltons/Haynes/Motors. Torque the TB as well. All the other items still apply.

Reply to
=?x-user-defined?Q?=AB?= Paul

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