Thanks for all of the help over the last year.
I have a 1990 L98 with 25k. The car for the most part is a garage queen.
The car runs great except that it cranks for some time before starting. I don't
mean that it cranks for 30 seconds, but probably 5 seconds. I have replaced
the wires and cap with MSD quality replacements and I run the bosch platinum 4 plugs. I have cleaned the injectors in place and run a good quality fuel. Fuel rail
pressure is where it should be. Also I have a modified air cleaner with a K&N filter. My cars in the past usually start on about the second revolution. Not this one. Has anyone had the same problem? Thanks

 

Have you replaced your fuel pump? If so, GM or aftermarket or ??

I just replaced the fuel pump on mine and began experiencing the same symptoms.

Was told by a friend and guy that does a lot of the work on my vette (when I can't/don't have time), that there is a valve or ? in the pump that allows it to build and hold pressure after the system is shut down.

Check your fuel pressure after the car has been off for a while and see if it's holding.

If I leave the car for a short while (1/2 +-), then try to start it, it just turns over but can't seem to get enough fuel pressure to start. I stop, retry immediately and it starts. Seems like it has to build up pressure. Even after it starts it still runs a little rough for a few moments.

Hope this info helps.

Good luck :cheers: :seeya :flag


[Modified by STREETKNIGHT, 11:54 PM 10/12/2002]

 

Thanks for the reply. I tried a few times turning the key and leaving it on for a few seconds before I tried to start it. This I thought would bring the fuel rail up to pressure. It had no effect! I'm stumped.

 

I do the same thing and it doesn't seem to help. I actually have to let the engine turn over a few times, stop, then try the restart again to get it started.

It's like turning it over increases the fuel flow until it build enough pressure. Just letting the pump do it's thing just isn't enoug. Try this and see if it helps. Please let me know. A buddy of mine is going to show me the problem and a way to fix it without having to buy another pump.

By the way, is your pump a GM dealer part or?

:seeya :flag

 

My pump is the original. Also, I have noticed the same behavior. If I crank it
a couple of times, stop then try again- It starts on half a revolution.

 

check your coolant temp sensor on the front of the manifold, under the TB. Mine was loose and not making a good conection. It was getting the symptoms as you until it came loose completely and the car would not even start at all!!!

I plugged it back in and now it starts on 1/2 a crank, first hit of the key.

 

Adding to Gus's post, does the crank time change if the car is warmed up? Does it typically start harder when cold than hot?

dlmeyers 90 coupe zf6 3 speed shocks

 

It starts right up when cold. The problem shows itself when you shut it off and let it sit for awhile. If you shut it off and immediately restart it, there is no problem.

 

Check the c4 tech tips for this problem I guarantee it is one of the three things listed for Hard starting problems. All fuel related.. Check it out. I posted it a few weeks back.

 

I searched the tech/perf forum and came up with 2 other postings. They spoke
briefly about injector leakage. You spoke of three issues and I couldn't find
any reference to them. Also if it is injector leakage, is that somthing that is
serviceable or do I have to trash them? Thanks

 

I checked today myself and see it isn't there either, Strange. Ok I had the exact same problem you are having. This is the GM test for the fuel system to find a leak if indeed you have one which it appears you do.. Get a fuel pressure guage remove your fuel pump fuse start your car and let it run till it dies. Then turn it over a few more times. (don't worry if it never started that probably means you had no fuel pressure which is suspect here anyway) Now connect your fuel pressure gauge to the schrader valve on the fuel rail. Oh yeah you will need to have a couple of vise grips to pinch off the feed and return line (rubber hoses) near the tank under the gas cover.. The way the test works is this first turn your key on and off a couple times to prime the fuel system.. It should put your pressure around 38-40 PSI then watch the guage odds are the pressure will start to drop immediatly. If it does prime it again and try pinching off the return line the lower right hose if the pressure stops dropping you have a bad fuel pressure regulator. If it doesn't remove the grips and prime the system again this time clamp the feed line *upper right hose If the fuel pressure holds It is a problem behind where you crimped the line IE fuel pump, Fuel pressure dampner, or a hole in the metal line in the tank between the hose and the pump which was the case in my car. If the pressure does not stop dropping clamp both the feed and return line and If the pressure continues to drop you have a bad fuel injector. Hope this helps.

 

Eric,
Thanks for the information. The next two weeks are quite busy for me and I
won't be able to get at it. First chance that I get I will run the test and let you
know the results. Thanks again
Charlie