Car has spark, will start on starter fluid, pump isnt priming at all.

Going to replace relay 1st. I cant find it! Another member sent me a pic, put I dont have anything like that under my hood!


I took some pics of the area where the relay was in the pic I was sent. I also took a pic of the relay they said was for my car.

PLEASE HELP ME!! I havent been able to drive the vette for a week now!!

edit...click on the pic of the car to see the album

 

I not positive, but I don't think the FP relay is in the same location on the 90-91 as it is on the 84-89. I think I have read before that the relay is under the passenger side dash. Perhaps someone can verify or disconfirm that. The pic I sent was from my 86 which is by the windshield wiper motor.

If you have tried to start the engine, as long as the oil pressure switch is good and you can achieve ~4 psi oil pressure while cranking....the fuel pump should run. Again not sure about the 91, but on my 86, you can use a jumper wire from the positive side of the battery to terminal G of the ALDL (all the way to the left bottom terminal) and it will run the fuel pump continiously until the wire is removed. You can remove the gas lid and rubber boot and test the fuel pump connector above the tank with a test light or voltmeter to see of you are getting signal.

Also, if you are quick and without the jumper wire, you can use a test light on the fuel pump fuse. Turn the key "on" and within 2 seconds touch the fuse with the test light to ground. If the relay is good the test light will light up and then go out....within 2 seconds.

Last test is to remove the fuel pump and supply a direct 12v source and a ground to the pump. If it is good, you will hear it.

Check the fuel pump fuse also. By spraying starter fluid in the intake while cranking and the engine starts....this pretty much tells you that you have a fuel problem. A fuel pressure gauge is handy in this situation.

 

That was on the pre-90 cars, doesn't apply to your 91.



I pulled up the parts book, shows the relay sticking forwards out of the harness, part number 14100455 should be on it. Looks like it could be up front, maybe near the throttle body.

 

Just to be safe I pulled the panel under the glove box and it isnt there. Central coaster, I dont know of any wiring like that near the throttle body. I stood out in the pouring rain trying to fix this, surely someone has a pic or can give me the exact location.

Thank you.
Devon

 

Should be same as '90.

Under dash , group of 3 square Bosch relays in a common holder.
Have loom out of car but relays are approx 1 foot to left of fuse box.
At the same location, several other looms exit main loom including wiring to RH door , passkey box and another 2 seperate similar relays

 

It's not under the hood, it is located under the passenger side kick panel inside the car. When you remove the carpeted peice, there will be a strip with 5 relays running horizontal to the firewall, the fuel pump relay is the one in the middle.

 

Found the group under the glove box. There is a set of three then a set of two. I replaced the middle one in the set of three. Still hear nothing from the pump and nothing comes out of the schrader valve.

 

I believe the fuel pump relay for L98 is under the dash behind the right hand side of the instrument panel.

The fuel pump #1 relay under the passenger side dash is only used if you have a ZR1.

 

The relay is probably good...and you fuel pump is dead. Try the tests above.

 

My only concern is, I've never had a pump just "go bad". there were always signs leading to it. Oh well. I will see how it goes when I get home tonight.

 

This test still powers the pump through the closed contacts of the fuel pump relay. So if the relay connector is bad or shorted, or the relay is destroyed internally, this might not work.

 

Might not...that's why I listed a few ways to test the fuel pump and circuitry.

 

Well I'll jump in.... My 91, the fuel pump just quit on me this Wed. A.M. with no warning signs what so ever. Fired right up, drove it about 2 miles, stopped for 5 mins. Got back in put the key in turn and no noise from the fuel pump before the engine turned over. It started a few times, but coffed and sputtered like it had run outta gas. It's now in the shop and it's definitly the fuel pump and they might have to replace a sending unit as well from what they're saying.

 

I tried all the relays. They appear to be ok. I bought a new pump today. I cant get the rear cover off the tank though. Looks like the screws are stripped. Oh, well. Off to a shop to get screwed over I guess.

 

There are 4 philips head screws that hold the gas lid assembly down. Try and pull up on the lid as you unscrew them. Once that is off you need to take the gas cap off to get the rubber boot out. Make sure to clean everything good before taking the cap off and again before taking the pump out, if so.

First try and apply 12v and check the ground on the assembly. You can test the fuel pump while in the tank as long as the connections at the pump are good. If it does nothing, then remove the nine bolts. Each one should have a o-ring around it...inspect and replace if needed. If the rubber gasket seal looks bad replace it too.

 

Woo Hoo!! Just went ahead and replaced the pump. Car runs like a champ!!!!

Thanks to everyone!

 

 

By the way I did go ahead and order the full 3 volume fsm from Helm as well!