Startup Issues

Bannon7414 · #1 07-02-2006, 02:01 PM

I have a 1994 5.7L Caprice and she doesn't want to start up for me. Could me needing a tune-up be the reason for her not starting right up and shutting off once started? If not what else could be the reason for all the starting problems.

capriceowns · #2 07-02-2006, 05:51 PM

Maybe some fuel pump issues?

Blue Bowtie · #3 07-02-2006, 06:24 PM

Maybe a little more information would help, like the standing fuel pressure as capriceowns suggested, and if there is spark during the no-start episodes. Any information you can supply would probably help.

Depending on mileage, the OptiSpark is a potential suspect, but that's not a diagnosis, only some information.

Bannon7414 · #4 07-03-2006, 08:08 AM

I had a fuel system flush and a new fuel filter put on not even a month ago, I have never tuned the car up and I've owned it for a year so i dont know when the last one was. I have barely driven the car in the year I've had it I probably haven't put 2000 miles on her.I have also replaced the battery and alternator within the last 2 weeks. Like i said the car only starts when i press the accelerator to the floor and if i dont continue to hit the gas once she turns over she shuts off, but if she starts and I keep hitting the gas for about a minute or so she will run, rough but she runs. And she also hesitates at acceleration after braking.

broughy84 · #5 07-03-2006, 10:14 AM

How many miles are on the car?

Blue Bowtie · #6 07-03-2006, 10:21 AM

THERE'S some information we didn't have before. If you have to floor the accelerator to start the engine, that's an indication of a flood condition. Throttle opening above 80% at startup stops injector pulses (Clear Flood Mode) and admits extra air to allow startup of flooded engines.

The two common possibilities are an injector(s) leaning through or a pressure regulator with a ruptured diaphragm. The injectors are a little harder to examine, so start with the FPR.

Remove the vacuum hose from the FPR and cycle the fuel pump. If fuel spews from the vacuum hose port on the regulator, it is running through the hose and flooding the engine. There should be no fuel present in this vacuum line. If it remains dry, the FPR is probably O.K.

Injector leakage can be diagnosed with a pressure gauge. If the pressure falls off within a minute, the injectors MAY be leaking the fuel into cylinders. If the pressure falls off, clamp off the fuel return line and repeat the test. If the presure still falls off quickly, the leakage is either the injectors or the check valve in the pump. If the pressure remains relatively steady after clamping the return line, the leakdown is likely through the regulator. If the regulator leaks through, that should not be contributing to the hard starts.

If the standing fuel pressure after shutdown remains relatively stable for ten minutes or more, the injectors and regulators are probably intact. That would indicate a problem other than flooding.

Bannon7414 · #7 07-03-2006, 10:36 AM

There's roughly 150,000 miles on here.

Bannon7414 · #8 07-03-2006, 10:48 AM

So what you all are saying is that the minor issue of needing a tune-up isn't my problem. I have had a strong feeling that it is a fuel issue as well but a few of my mechanic buddies say all i need is a tune-up. If the injectors or the FPR is the problem will i need to replace them? How many injectors are on a 94 Caprice?

HLandin · #9 07-04-2006, 03:41 PM

Your '94 Caprice will have eight injectors, one for each cylinder, since your engine uses sequential port injection.

Bannon7414 · #10 07-05-2006, 07:59 AM

I went to start her yesterday and she didn't turn over at all, even with me hitting the gas. If the engine is flooded will i have to get an entirely new engine or is there something else i could do. I'm getting a diagnostic test this weekend hopefullly that will let me know the culprit.

Bannon7414 · #11 07-06-2006, 03:03 PM

I went and put gas in her so I would make it to the diagnostic shop. When I took the cap off the tank I heard a "dry-hissing" sound come out of her. It sounded like whe you open a 2 liter of soda. Is this common or is this a symptom of something going wrong?

CD Smalley · #12 07-06-2006, 07:28 PM

Normal. The system is pressurized.

Bannon7414 · #13 07-08-2006, 08:58 AM

I'm trying to get her to the diagnostic shop again and now she doesnt want to start at all, she just keeps choking but no start up. When I went out the battery gauge was all the way down (resulting in no turn at all), I have a brand new 2 week old battery and alternator, why would she not be getting any juice? Was there something I had to do before putting the new alternator and bettery on? I am really close to giving up on her please help with any info.

capriceowns · #14 07-08-2006, 11:31 AM

PLease dont give up on it, the battery is probably just dead from carnking the engine over, youll only have about 20 seconds till the bat is dead.

Just jump it, or put a charger on it, and go from there., or have it towed to the diagnostic shop

Bannon7414 · #15 07-08-2006, 01:04 PM

Good news, I got the diagnostic test done in my driveway. I know what the problem is. First off I'm in need for a tune-up, BADLY, and she din't have any spark along with "dumping fuel". So I'll be getting a full tune-up, replacing the Core and Module plus a list of other minor things. I had the injectors and FPR checked and they are fine. I will give an update to you guys when I get her back. What the hell does "dumping fuel" mean and how is it resolved?

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