1999 SL2 Wont Start/Hard to Start in Hot Weather

[BlueOgre]

Ok, this is a really annoying problem and i cant seem to put my finger on what is causing this. About 2 weeks ago, when the weather started getting hotter, my car started giving me a lot of problems starting. Its a 1999 Saturn SL2 w/DOHC. When i go to the car in the heat of the day, i hit the key, the car will crank/turn over, but it will not fire and start. Most times when the temperature is reasonable outside, but not always, if i let it sit with the ignition off for a few minutes, around 4 mins or so, i can go back to it, try again, and it'll generally start right up. However, if the temperature is in he 90s i can take me upwards of 30 mins cranking on and off to get it started. I thought perhaps i had a sensor going bad, so i plugged my OBDII scanner in and 99% of the time i get no errors, even when the car wont start. Twice, when it first started doing this, i got 2 errors, both reporting Cam Shaft Position Sensor, but i havent gotten any errors since. Anybody have any ideas?

[madpogue]

Your car doesn't have a cam position sensor, so when you get codes related to it, it actually means something wrong with the ignition system (coil packs, spark plug wires, often it's just not grounded well).

The no-start you describe is a classic crank position sensor story. Two quick tests to try whenever you have a no-start:
* Poor-man's fuel test - Turn off the radio, blower, etc. and turn the key to RUN (but NOT to START). You should hear a "whirr" of an electric motor behind you, for about 3 seconds, followed by a "click" from the inside fuse box. That's the fuel pump priming. If you don't hear it, you'll have to start diagnosing the fuel pump relay, fuse, wiring, the pump itself, etc.
* Poor-man's spark test - Remove the #1 and #4 spark plug wires at the coil pack. Have someone turn the key to START for a few seconds while you observe under the hood. You should see a spark jumping between the exposed coil towers. If you don't, first suspect is the CPS.

[2001sl1]

I want to thank you for that reply, because I am having the exact same problem with an 01 SL1.

[auxmike]

I've owned both a '93 SL1 and now have a '97. They both seemed to need two trys to get the engine fired up hot. In my '97 I give 2 short bursts of starter knowing full well it won't start first try.
BTW: I keep a real nice spare Valeo OEM starter in my trunk...just in case....

[madpogue]

Auxmike, your '97 probably suffers from the classic '97 fuel pump problem. Pump works fine, but fails to hold stored pressure when the car is parked. Rather than cranking (and prematurely wearing) the starter an extra time, try this: turn the key to RUN, and listen for the fuel pump to prime. Then turn it back to ACC, and to RUN again, and let it prime again. THEN, try to start the engine. If that works, then you've got the classic problem. Permanent fix is a new fuel pump; SPENDY! Best "workaround" is the "Wolfman method" (well, until he traded it in...) - turn the key to RUN, fasten seat belt as pump primes, turn the key to START.

[auxmike]

I'll give it a shot. I hate sitting there waiting for the pump to prime though...
Patience, patience!

[BlueOgre]

About a year ago i put a new fuel pump and filter on the car. When i turn the key on i hear the pump prime and kick off, yet still sometimes the car will not start. I've had to put 2 crankshaft position sensors on the car before, this was, i'd say, about 6 and 9 months ago. I didnt think that would be the problem again, but as that is the simplest thing to replace at this time, i'm going this morning to get another one, maybe 2, one to replace and one to keep handy. I'll keep you guys informed of what we find, maybe it'll help someone else with a similar/same problem.

[fdryer]

madpogue's post #2 is about as succinct as it can get; definitely perform his instructions first before buying another cps. It's a mystery if you have to go through more than one cps to correct the same problem repeating itself every few months.

[auxmike]

Funny thing is my car starts right up first thing in the morining stone cold. But if you drive it, go into the mall for an hour, come out THEN you have to crank multiple times.
I just changed my fuel filter after 55k of use.

[BarnOwl]

Fix the code and you'll probably fix your problem. This is about the best guide I've seen for diagnosing those codes.