sport532

I have a 1989 corvette that has a problem starting if it sits for about 2days. It acts like it is not getting fuel. You can crank it over and over and still it won't fire. If I give it a shot of ether it starts right up and keeps running. Once I get it started it starts easy all day.
I don't know if it has anything to do with this but when you tun the key on without the car running the fan starts up and runs, the engine is cold.

rithsleeper

Hmm. Prob some stupid switch is jamming like oil pressure or something. First thing I'd do is go past auto zone, borrow a fuel pressure tester and see what that is doing.

I'm more inclined one of the safety mech is locking out the fuel pump though.

Personally I got so sick of all that garbage I bypass anything that goes wrong. If I were you I would jumper the FP relay (green/black) wire to an ignition wire. Problem solved if the pump is indeed not turning on till the car is running.

The fan coming on could mean the comp thinks the car is warm so it leans out the mixture at startup. If that is the case then it could be the sensor but more likely the wiring. Iirc it is the coolant sensor on driver side head with the single pig tail. Not the one on pass side with the green plug. Those coolant sensors hardly ever go bad but it can happen.

Cliff Harris

Does your fuel pump come on for 2 seconds when the ignition is first turned on?

The ECM turns on the fuel pump relay for 2 seconds when the ignition is first turned on to prime the fuel rails for starting. It then shuts off the fuel pump so that it won't run continuously if the ignition is turned on but the engine is not started. If the relay has a problem, then the oil pressure switch backup will turn on when the oil pressure reaches 4 PSI. That takes a bit of cranking, which explains why there is a delay before the engine starts (not necessarily your problem, but a common symptom of a bad fuel pump relay).

The cooling fan coming on as soon as the ignition is turned on could be several things. The most likely is that the cooling fan cycling switch on the AC high pressure line is bad or the connection to it is open.

The coolant temperature sensor that the ECM uses is located on the front of the intake manifold under the throttle body. It (or the wiring) would have to be shorted to ground for the ECM to think the coolant is at a high temperature.

Some people install a manual switch to run the cooling fan(s) under the mistaken thinking that they are smarter then the engineers that programmed the ECM. For example, the ECM turns off the fan if the vehicle speed exceeds 35 MPH because the turning fan blocks the airflow through the radiator. Do you think the people with the switch will remember to turn it off when the speed is above 35 MPH?

sport532

I don't hear a fuel pump running to prime the fuel line.

sport532

I have had a Chet dealer replace 2 relays by the battery.

Vic'89

I had to replace my Fuel pump relay last week. It was on the Firewall , drivers side.

Vic

rithsleeper

those are mass air flow burn off relays. The Fuel pump relay is next to windshield washer motor. Has a big power, ground, and a green/black wire. If the relay was bad though it wouldn't run period, not just the prime.

Rig it with the ignition. So easy, never have the problem again if you test to see if the prime isn't happening….

Vic'89

I think I have to disagree with that statement.
My FP relay was bad, it was not priming the fuel pump, it took a few extra seconds to start the car.

Vic

sport532

I'm going to replace the fuel pump relay!

sport532

I replaced the relay. It did not fix at all, it still just turns over. It is still not getting fuel. Help any other ideas

jtc44

I must ask Have you checked for power and grnd. at the relay?
Have you checked for power and gnd. at the pump during the prim and during the crank? Have you checked for power and gnd at the pcm? Have you jumped the pump at the relay to check for fuel? Hae you looked at a FSM to see how it is wired?
Safe to say pump is ok it does run so what is missing during crank? I am thinking that wiring needs to be checked very close
Best of luck.
PS Cliff has it right!

cv67

x2 would check these two things out

Seems common on 89s the cold start takes a little longer mine did
Shoulnt have to crank and crank though.

Bandit1200

I have the exact same issue with my '89. I've checked out a few things and the one issue that I have noticed is that I'm losing fuel pressure very quickly after the car is shut off. Unfortunately I haven't had time to go much further with it, but check yours too as you may have a leaking injector. I have jumped the fuel pump to let it run for a minute or so before starting the car but that makes no difference. All I can think is that the injectors, or at least one of them, are leaking and flooding the car. Once it starts it's perfect all day, but when it's cold I have to crank it for a long time before it starts to chug and eventually will start. Sometimes it takes me about 5 minutes of cranking and waiting, cranking and waiting...

It would be interesting to know if you're losing fuel pressure when the car is shut off too.

sport532

I have had new Bosch injectors put in it makes no difference. I can get mine started if I give it a shot of either.
Mine seems to be more of a problem of no fuel. It starts real good all day once I get it stared. I'd say it starts in 1 to 2 seconds.
Could you explain to me how you jump the fuel pump, I don't want to use any more either to get it started? but I do want to check all my connections to see what electrical problem I may have.

sport532

I found the problem, car starts right up now!
Behind the battery there is a post with about 6 connections. All of the terminals were corroded. I sanded all of them and now it starts right up!

Tom400CFI

^That is wrong.


Car will still start and run, with extended cranking, b/c of the oil pressure switch that also, in parallel with the relay, sends power to the pump.