Starting Problems-sometimes

93SCGal

Registered User
Hey guys! I haven't been hanging out on the boards much lately. I thought my problems would just go away if I ignored them!! LOL! I'm going to try and explain what is going on. My car sometimes will crank fine. Others it won't. It can be cold or hot. I can drive a mile down the road get back in and it won't start. When I'm trying to start it, it turns over fine, the fuel pump is running, but it ACTS like it's not getting fuel. You can push the pedal to the floor and it does nothing. Then it will lope so to speak (very rough) and die. You have to stay with it for a while but it will eventually crank. But when it does Wow, it just billows smoke! And smells awful! Then it's fine. Any ideas? Don't know if it's related but it seems to be idling high (sometimes when cold) and you can't "get a go gear", it's like you shifted in to neutral, but the idle will come down and the gears will catch and you can go. I haven't had my mechanic look at it yet, but I like to have some idea before I do-he's not a SC'er! Could possibbly be transmission has 219K on it! Had it checked out about 10K ago and everything was fine but....Oh and if anybody remembers the vibration- still there after new rear rotors and u-joints! I'm almost at wits end! Just can't stand the thought of selling her! Any help would be appreciated or if anybody know of a good SC mechanic in the vicinity of Shreveport, LA let me know!
 
I bet it's a bad cam sensor. Next time when you go to start your car, see if the upshift light comes on as you crank it. That should tell you if it is bad or not. I'm thinking that's what it has to be.

Thomas
 
What he meant to say was crank sensor. The uparrow lit while cranking the engine during a no-start indicates the crank sensor signal is missing. Neither the cam sensor or crank sensor will throw a code. The cam sensor can cause a no start, but its symtoms are usually a bucking and wavering idle tach.
 
Similar problem

I had a similar problem with my 90' SC it would give a hard start every once and a while then it would start fine 2 seconds after cranking it the first time. I also had rough erratic idle and every once and a while a small pulse in the RPMs at any range of throttle position. I checked all my connectors and ignition wires and traced it to my cam sensor. I replaced that at $25.00 and haven't had any problems yet. I sure hope the problem does'nt come back cause i cant stand driving my brother-in-law's 85 Camaro! :mad: Hope this may help you in figuring out whats bugging your SC.
Good Luck, Greg
 
I had an intermittent hard starting problem accompanied by lots of smoke when I finially got it started. After replacing nearly every sensor on the car, I found that the fuel pressure regulator was leaking gas thru the vacuum hose.

A simple test for this is to hook up a fuel pressure gauge on the rail and see if it holds pressure after turning the engine off.

If it's not holding pressure, it's either a bad regulator or a leaking injector. Either one can cause the hard starts, rough idle and smoke your getting. If it holds pressure, change the cam sensor as others have suggested.

David
 
The awful smelling smoke is unburned fuel. By cranking it and priming it by turning the key on and off, the cylinders are filling with fuel. Then when it runs not all of it burns up and gets blown out the exhaust valves and through your pipes. It could be a cam or crank sensor. Usually crank sensors cause the car to stall. The rough idle could either be a vacuum leak or a dirty IAC (idle air control valve mounted on throttle body next to your TPS (throttle position sensor) the IAC can be removed and cleaned).

As for the vibration after u-joints and new rotors, are your tires set at close pressures? You sure you don't have a wheel out of balance? Is your wheel bearing bad (jack up car and see if wheel wobbles top to bottom). You may have just lost a weight from your wheel.

Also when the u-joints were changed did you have the driveshaft balanced?
 
Well it has a new crank sensor on it! Maybe its bad. Don't know. As for the driveshaft-yes it was balanced. It has new bearings, the pressures are correct and the wheels are balanced. Thanks guys!
 
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