starting problem fuel related

[derhells]

Originally Posted by derhells

This is such a intermitent problem, (no start) today I get home from work, have not started it for about 24 hours first turn of the key and the thing fires right up like nothing is wrong. I have had it running in the driveway for about two hours, thing is running like always. I have shut it down and let it sit for about ten minutes and it still fires right up. I am going to let it run for another couple hours and then pull it back into the garage and let it sit all night and see what tommorow will bring. Could it be that I just have a bunch of shit in the fuel line and that is why it will only not start when the stuff is in the way? I had just put a bottle of injector cleaner in the tank the first day it really gave me the no start about 30 turns of the key and some of that with a jumper box attached, wonder if the cleaner is starting to take effect. I know that sounds like wishful thinking but wierder things have happened. I will let you know what the fuel pressure reading is when I take it in the morning if I still have a no start. Thanks again Derek

So I got my hands on a fuel pressure tester and tested the pressure and got low 50's. This was with the car starting. I think if I was still getting a no start the pressure would be lower. I would turn the key and the gauge registered about 52-54 so I got back in and turned the key the rest of the way and got a hard start. So now I am thinking the problem is with the fuel pump and I am not getting enough fuel to the engine for the proper start. Does this sound right? Any feedback would help as I am not looking forward to dropping the tank, but would rather do that then have to put in new cpi. Thanks Derek

[zonie77]

I went through this with my 95 Blazer 4.3.

If the fuel pump gets worn (the inlet filter or sock split on mine and pieces of it were going into the pump) the pressure will drop and you will get starting. Mine was down to 42 and it would not start without starting spray. It should be about 50 which yours is. That should be supplying enough fuel.

The "spider" or CPI uses nylon hose. It cracks with age and leaks fuel into the intake. The top of the intake actually comes off pretty easily. If you have standing fuel puddles the CPI needs to be changed. There is a connector piece, nylon line of course, that should be changed at the same time. Mine went bad shortly after the pump. With the leak you are not directing the fuel to all cyls. This is probably what's wrong with your car.

Some intakes have a plug about 1 1/2" diameter that you can take off and look inside for fuel puddled. Don't run it with the cover open.

If you do this yourself it may be worth it even on a vehicle with high miles. I'd check rockauto.com or gmpartsdirect.com for prices. Autozone may carry it now. I got a deal at that time and paid about $250 for the CPI and $50 for the connector.

[krazi]

try the ingition control module

[RayzHell]

Try a crankshaft sensor. It's on the right side of the engine under the plastic plate that covers the oil filter.

Ray

[Chris Stewart]

It would be more info if you could check for plug firing and fuel pressure during the no start cranking.
The fuel pump runs for a few seconds after you turn the keyswitch on then the oil pressure has to be normal before it'll come back on....normally a coupla seconds after the motor starts.