[rss560]

I have a 98 Deville that cranks but won't start. It may run fine for a day or two then won't start. The dealer said to replace the crank sensors, so I replaced them and no luck. It also, at times died and was told to change the EGR valve as well and did, but it still died cruising down the road. I'm trying to help my parents, as a shade tree mechanic already over-charged them on a fuel pump and ignition module. Any ideas?

 

[Caddyshack100]

You first need to run codes, both history and current, this will point you in the right direction, ignore the P1599 code, stall or near stall, I think you got that one figured out. It could be several areas, even a plugged fuel filter, a bad FPR, or a plugged Cat. Without codes though, this is just shooting in the dark, post back with the codes, on top of the page you will see a sticky on how to check with your car.

 

[rss560]

Thanks...The current code is IPC U1255
There are plenty in the history
PCM P0603
IPC B1552
TCS C1255
TCS C1276
TCC U1255
PZM B1552
" "B1982
" "B1983
" "U1255
RFA U1255
RFA U1300

While I was checking, I was able to start it after it struggled for fuel, but it's never consistent. Thanks for your help!

 

[ewill3rd]

You have to have 3 things for an engine to run.
Spark, fuel, and compression.
Those are the basic places to start, it sounds like someone has you running backwards here.

I usually start with fuel. Make sure you have fuel pressure. There is a pressure tap on the fuel rail for a gage. The best thing to do is install the gage and crank the engine. If the pressure shoots up to 30-40 psi then the next thing might be to look for injector pulse. A long screwdriver or mechanic's stethoscope would be good here. Have an assistant crank the engine and hold whatever you have on an injector, you should hear it clicking pretty good while the engine is cranked.
If that is good move on to spark. Go to any parts store and get an ST-125 spark tester. Clip it on ground and pull one of the plug wires out. Connect it and crank the engine, you should see a spark across the tip of the tester.
If that is good you can do a compression test to make sure you aren't up against a mechanical issue, but my guess is after the other tests you won't even get that far.

You could have a bad fuel pump relay, no gas in the tank (even if the gage says you do), or some sort of wiring issues. These tests should point you to at least the right system.