Engine dies when warm and throttle is pressed

[etsalisb]

I have a 1993 SL2 I bought to fix up a couple of weeks ago. It needed a new radiator and tires, so I put those in as well as coolant and trans fluid, and then I was able to drive it around for that day, and it ran great other than the engine light coming on when I pressed the throttle, then disappearing after I let off.

I tried some auto parts stores to try and get the code read, but nobody had an OBDI scanner, so I just drove it home and changed the oil. The oil change went smoothly (Other than a intensely stuck on oil filter), and I started it up after, and it ran so much smoother with the new oil in it. However, when the engine started to warm up, it stalled out. I checked the oil level, and it seemed that I accidentally put in slightly too much oil (oops).

I drained the oil until it reach the proper level, but it still wouldn't run! My buddy suggested it was the battery, so I had the battery tested - toast - and replaced it the next day and it started right up. Tested the alternator, it was good. Then, the engine warmed up and I put it in gear, then it stalled out. I did some research, and found that the crankshaft position sensor is a common problem and has that same symptom of stalling the engine when warm, so I replaced it, started the engine, and it idled even when it was at operating temp.

So I thought that had fixed it, however, as soon as I touched the gas pedal, the engine sputtered and died immediately. Trying to restart it is useless, and can result in backfire. I have to wait for the engine to cool all the way down for it to start.

My current suspects are the throttle position sensor, idle control valve, ignition coils, ignition control module, and possibly (hopefully not) fuel pump and filter. What could cause the engine to run fine all day, but then die and refuse to start again when the gas is touched?

[marko16]

Since it runs fine, I'd rule out the ignition system for now. Since its temp related how about temp sensors.

[fdryer]

Try using a paper clip and this; http://www.differentracing.com/tech_...diag_info.html.

Until more background info is given, guessing on worn out parts is next. Fuel pressure is the only way to determine whether or not the pump is worn out. Fuel filter clogged? Rubbers used everywhere for sealing against intake manifold leaks may suffer dry rot; map sensor and its grommet, vacuum lines, vacuum brake boost vacuum hose and its grommet, etc.. Dirty throttle body, faulty idle air control valve, someone meddling with the throttle stop screw that isn't supposed to be meddled with and altering how the EFI system manages idle rpm, original two wire coolant sensor never replaced with the flat nosed brass one, a leaking TBI injector if this engine has TBI before side draft throttle bodies became the better solution with cylinder injectors........

[etsalisb]

I fixed the problem, now my Saturn is running perfect, ready for another 100K.
It ended up being the ignition control module, even though it seemed to idle okay until it was warm and the gas was pressed. Coils, wires, and all sensors were fine. Brand new, the ignition control module is over $100, however I picked one up from my local junk yard for $20, and it has been working fine. I just thought I would post what the solution was for anybody who is having a problem similar to the one I described in my original posting.

[marko16]

So much for my help. When mine have gone, I get no start right off the bat.