Rough Starting

[crookshanks]

In the mornings, or if I let the car sit for a few hours, when I go to start it, it acts like it has no fuel. I replaced the fuel pump and filter the other day and it is still doing it. Once the car gets fuel, it runs fine. Any other ideas as to why this is happening?

 

[MichiganTeddyBear]

check to see if the fuel pump is 'priming' the system when you turn the key to 'on' (not all the way to start). it should run for a couple of secs without the engine running. if it does not run, there is a relay (can't remember exactly where) that may be bad. the EEC turns the pump on for a sec via one circuit to prime, then when engine is turning over (signal from distributor), it energizes pump via a 2nd circuit.

also, the fuel pressure regulator could be leaking and letting the accumulated fuel pressure bleed off to the tank when the ppumps not running for a long time.

which filter did you replace?? the sock in tank, or the one in the fuel line??? the sock only keeps the big chunks that will hurt the pump out, the one inline takes care of the rest that will hurt the injectors

 

[crookshanks]

I replaced both the filters, sock and the inline filter.

The pump is priming as well.

 

[crookshanks]

I had scanner hooked up to the car and it seems that there is more wrong. The RPM's are the most noticable as they jump from 16 to over 15,000 in one second intervals.

This all started when I had the exhaust done last week. After I had it done the check engine warning would come on and go off all the time. So I took it to the shop and discovered one of the O2 sensors was left unplugged by the exhaust guy. So when I plugged it back in and drove the car some more, the light still came on. Next when I replaced the fuel filter, the fuel pump died as well.

So where I am at now, the computer is still telling the car the the RPM's are crazy, it has a new fuel pump. I thought maybe the dash was causing the problems as the RPM's run through the dash, so I took it out and tried running it and it worked for awhile but then the RPM's went crazy again. I have tried another computer as well and that does not seem to fix it.

Any ideas on this one?? It is pretty serious. Thanks!

 

[MichiganTeddyBear]

the rpm's don't go thru the dash to the best of my knowlege. the EEC feeds the dash all the engine related info (other than oil press, water temp, and voltage).

I would guess you got a distributor problem causing your rpm jumps... either worn, or PIP problem (profile ignition pickup).