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84 cutlass supreme. Bought it and drive it an hour home. Died once after putting in gas and took 30 minutes to start up again. Made it home, now it won’t stay running. Idles then dies, or is shifted into reverse or drive.
when I get a used car I change out all filters, including the one in the gas tank. cars sit a lot, and the crud on the bottom of the gas tank gets sucked up while driving.
ethanol gasoline doesn't help either. might be worth a carb rebuild by someone who knows their stuff and uses an ultrasonic cleaner and other nasty solvent stuff.
Hard to diagnose on the interwebs with all that information. I'm going to assume the engine is stock and in otherwise good repair. Does it do ok off idle? Driving down the street, does it hate life or things seem to work ok? My money is one too many vacuum leaks. Fuel filters could cause that issue, as mentioned, but normally that rears its ugly head at higher rpm, but not always. Either cracked/broken/disconnected vacuum lines or loose carb, any/all of the above. Not uncommon for cars that are nearly 40. Very unlikely the torque converter clutch is engaged but then again, stranger things have happened.
Additional thought, timing chain? How many miles? The timing chains have nylon gear teeth on an aluminum cam gear and over the years the teeth break off and end up in the oil pan, and the timing chain is loose as a goose really retarding the cam, or could jump time.
Do the easy and free things first. Check ALL your vacuum connections for cracks and being unconnected. There's a mile of spaghetti on these cars, so plan to be there a good while. Make a list of sizes you need (sometime's the sizes are marked) and replace them all if you plan on keeping the car. CHECK the tightness of the carb mounting bolts (1/2" headed bolts). Check the tophat of the canister vent TVS on the passenger side front corner of the intake. They get old and brittle and the spring has been known to blow the top off of these. The canister control disc valve right between the carb and TVS connected to it sometimes develops a diaphragm leak so check that too.
Another semi-common vacuum leak area that can drive you nuts that hardly anyone ever checks on these cars is the HVAC control head vacuum port selectors. If you hear constant hissing from the dash, some work is ahead of you. To temporarily elminiate it, there's a hard tube connection (pinkish to violet color) behind the carburetor on the intake line. Remove that and plug the intake side port when checking for leaks if you hear the dash hissing at you. If the hissing stops, then an HVAC head rebuild may be in your future. Don't forget to plug that tube back in, that's the vacuum supply for your HVAC. Those port pods in the HVAC head unit are held together by plastic clips and sometimes they come loose or simply give up and break. And they're made of unobtanium.
Or- it could be something else entirely. Good luck, we're all counting on you.
^^^ What Joe is explaining is, if the torque converter clutch solenoid has failed and the converter is stuck in lockup mode, when you put the car in gear the converter has no slippage and the full load of the drivetrain stalls the engine. This usually triggers a "check engine" light. Is the light on?
Try this. Disconnect the battery cable for a minute or so. This clears out any fault codes in the car's computer and resets everything to factory defaults. Reconnect the battery, start engine and try putting the car in gear.
Stoopit **** like this is one of many reasons I despise computer-controlled cars, or anything else. I am dreading the day my analog appliances die and I'm forced to get something with a motherboard.
I appreciate all the feedback. 85k miles on it. When running it runs smooth and shifts smooth no slipping. Got it up to 50 on the back roads a little over an hour drive. As soon as I stopped for gas it wouldn’t start back up. Took 30 minutes to get started then got back on the road for another 40 minutes. Got it home parked it, started it an hour later and it would just die. Got it idling for 5 minutes then it would die. Reverse seems to be the only gear that it wants to try and die in. Got it started today an it idled rough for 5 minutes, put it in reverse and it almost died. I had to immediately press the gas to back it out of the drive way without it dying. Drive it around the block and to the nearest shop where they’ll be able to take a look at it on Tuesday.
It's also possible that it could be an ignition module. Those mostly fail all the way, but sometimes they start acting up similar to the way yours is acting.
If you're taking it in, hopefully they'll be able to tell you more, hopefully. Not all mechanics are well-versed in carbureted OBDI cars. You may get lucky.
Cranks fine. Just stalls out shortly after whole idling.
Well, unfortunately there are about a bazillion possible causes, from leaking float to excessive fuel pressure to problems with the CCC system to incorrectly adjusted carb to leaking vacuum line to problems with the A.I.R. system (which can fool the O2 sensor into a false air/fuel reading). You can measure the float level with the engine running to see if that's the problem.
Never knew of that float gauge, Does it just float on top of the gas and you read it??
It sits on top of the float. The gauge is light enough that it doesn't change the level of the float. There are different ones for different carbs. This lets you check the float level with the engine running.
There's a slot to access the top of the float (see blue arrow in pic below) but the GM-supplied measurement reference to go by is either 11/32 or 14/32, +/- 2/32" depending on the carb number. 17084256 and 17084258 are the only 84 Q-jet carbs to have 11/32" float levels. All other 84 Q-jets use 14/32" as a float level. The measuring tool needed is either J-34935-1 or the one mentioned above, BT-8420A. Either will work as specified in the CSM. Finding one, though, proves to be the trickier part.
From the 85 Olds CSM. 84 is same procedure, it just doesn't give the measuring stick part numbers.
If the float level is greater than 2/32" off, the float may need adjusting. The proper way to adjust the float level per the CSM is static only with the float weight, a straight edge and ruler, or T-scale and bending the float arms with the carb top off. That loop handle sticking up in the picture is the tool for bending the float to the proper level position. You don't have to have the specific carb tools, but they sure make it easier.
The Y engine (flat tappet) for 1984 has a rich stop and a lean stop. Roller engines 85-up have a built in rich stop so there's no need to check it since it's pre-adjusted.
Checking primary jet plunger travel- (has nothing to do with float level but does use the float gage)
Rich stop reading
Gently press down until plunger stops moving on the Lean stop. This reading is- 4/32", aka 1/8" total travel. Perfect.
Good luck, we're all counting on you.
