Have a 2002 SL2. Have owned car since 2010. Battery 2 years old, plugs less than 5000 miles. Car has aftermarket remote start that I installed 4 years ago.

car turns over but will not start. Pops and almost backfires but will not start. Will run if you spray starting fluid in intake. plenty of fuel pumping after fuel pump and at fuel rail. Is there something that shuts fuel rail/injectors off? Or what could be the issue?

 

If it will run on starting fluid does it quit when you stop spraying or continue to run? Can you touch the injectors on your car while running it on starting fluid? They should click and you can feel it.

 

Right off, I'd suspect either the fuel pump or the pressure regulator. The regulator is about $90, so don't just go get one without further testing. I'd grab one from a junker first and test it that way.

 

It stops running when the starting fluid is stopped.

I need to run more tests, but it has been -15 degrees for the past week and the car is in a parking lot.

This is the 4th time in 7 years this car has done this. Has not really been a real solution or fix in the past yet it started running in the past after time.
First time I cleaned and replaced a coil pack. Second time it sat for a week then started, third time (last summer) tried the key from the remote start under dash and it started and has ran since while using both keys. this is the 4th time and looking for answers. or an idea
Has anyone else had a similar situation....cranks, pops and almost backfires, but will not run, runs while popping some starting fluid in fresh air intake.

 

here is some more detailed info.

The more I think about this it seems to happen in extreme weather - hot and cold.

The first time this same issue happened was before the remote start was installed. 5 years ago in summer same issue, I read that a coil pack grounding can cause this. I dropped the coil packs cleaned the area and replaced them. Car started and ran for a few years until it happened again. This time in cold weather (-0) At that time I replaced the coil packs again, but it did not solve the problem. Towed it to a repair shop. They pulled the plugs let the car warm overnight, replaced the plugs car started. Third time, summer of 2016, hot out 90+. Checked fuel pressure at pump and rail and was good, changed plugs, NOTHING. sprayed stating fluid in fresh air intake and it would run until you stop spraying. Towed to repair shop. It sat there for 3 days. They ran diagnostics and no codes. At that time I told them to grab the key from the remote start module under the dash. The car started right up with the key. Forth time is now and I have not even started to troubleshoot as it is -15 out. My thought was to ask if anyone had any ideas before I dug into it. I have many things to try and I hope the weather warm so I can work on it. I will post what I find. If it gets to 30 degrees outside and it starts, I'm throwing my hands up and label it a a phantom issue.

I should add that all 4 times it has had the same symptoms. Turns over, at about every 3rd engine revolution, it pops like it will start, but does not. Forgot to mention that if you push the pedal to the floor, it will start to, what sounds like, a small backfire at the intake.

 

cyclicly pump the pedal to the floor two or 3 times and then hold it down. I think it is a flooding issue. My S cars do this every once in a while,. If you don't get it running on the first or second try, too much gas accumulates and you have the equivalent of a flood. Holding the pedal down clears it. It''ll take like 8 seconds but if you torture your starter and hold the pedal down , it will sputter, spit, boom and rock, but when it starts, there will be a huge plume of fuel rich smoke out the tailpipe.

THe fact that you say it happens in temperature extremes also leads me to believe your ECTS may have failed and is reading -40 all the time to the PCM, so the mixture is always wrong. THis will be a super rich mix all the time but will have the most effect when it is really hot out (WAY too rich) and way cold out. Still too rich even for -15. Plus on those cold mornings it is very easy to run your battery down trying to clear the flood so hook up jumpers till a running vehicle.

Even with a functional ECTS, I was unable to start my 97 SC2 at -22 F because it did nit want fo fire on the first try, then I flooded it, then I killed the battery. Once hooked up to jumper cables, I did the flood clear above and after a fight it started.

 

How would that explain when spraying starting fluid in the fresh air intake it runs and then goes back to not when the starting fluid is not used? Thanks

 

did you try my suggestion?

I'm GUESSING the reason is that it runs with starting ether because the A/F needed for it to ignite in the cylinders is much less critical than the gas/fuel Aire/Fuel ratio.
Once you ignite the either, the fuel delivered to the cylinder will burn. It will burn non optimally but it will burn nonetheless.

Given that this seems to happen at the temperature extremes really leads me to believe your ECTS or the connector is bad or the wiring for the circuit is damaged. When this happens, an open circuit ends up telling the PCM that the coolant temp is continuously -40. Always. When it's -15 out. When it's 110 out.
Probably the most common failed part on an s car.
The A/F mixture is overly rich in both scenarios and can lead to hard or no start conditions. Very common on the S cars.

Inspect ECTS and connector after removing the squeeze connector. The connector terminals should be free of corrosion, orange stuff, green stuff. The sensor should be pulled (catch the coolant, do it on ice cold engine). You should find a fully brass tipped sensor. If you find a resin tipped sensor, I will almost guarantee you it has failed -- they ALL did.

I would replace it even if it is brass tipped.

Source the parts from a GM Dealership and replace the connector pigtail too. $45.00.

 

I'll give it a try tomorrow morning. It's still 9 below zero now and suppose to be in 20's tomorrow

 

I'm amazed at how many problems the frigging ECTS can cause on these cars. You can find the parts you need at most Saturn friendly GM dealerships. I had to order mine, but that cured the problems I was having.