JhStephens

Hi, fairly new to engines and brand new to corvette forum.

A short summary...

After sitting in a garage for the better part of 4 years, after replacing the battery some old spark plugs, the fuel injectors would not "fire" or "spray" (please let me know correct terminology) so I pulled out the fuel pump set up to find that it was gunked up and destroyed from sitting in old gas... (didn't know this could happen) So I clean out the gas tank, replace the fuel pump, and try to start it again...

Now the fuel pump don't work unless I physically engage the fuel pump relay, so I know I need to replace that also,,

When I engage the relay and let some fuel pump flow through the fuel injectors will spray when I turn the key. The car will start and Idle for roughly 3 seconds then die because other than the initial spray when I turned the key, the fuel injectors will not spray any more to allow the car to idle.

Any suggestions?

Sorry for my lack of knowledge, if I left any required information out, please let me know and I'll find out whatever you need.

terry82

http://www.crossfire.homeip.net/index.php?act=idxdid you replace the fuel filter on the frame rail passenger side?there is a fuse[fuel pump] on the fuse block that needs to be checked .

JhStephens

Fuel pump is working.. and the injectors are spraying the initial spray when the key is turned, although if it's still a possibility that those are causes for the injectors not to spray afterwards, then I will replace them both.

terry82

can you keep the car running by[i use a spray bottle of gas spraying fuel in?see what happens.iwant to see why the injectors stop spraying.one the computer thinks there is enough fuel pressure or the low oil pressure switch is turning it off.

autimous

I could be offering a dumb suggestion, but a similar thing happened to me because a wire came loose on the distributor cap, so no signal was being sent to the injectors/pump.

JhStephens

Thanks for the suggestions. I'll let you know what happens.

jdp6000

What you see when you first turn the key is the prime pulse. Its suppose to do that. It should continue to spay afterwards. there are a ton of things that could be causing what you see.

Does the fuel pressure climb while cranking...what does the guage say? Its a cut off.

Check the wires to the distributor as suggested. If the two on the driver side are not connected it will not start.

Follow the wires from the injectors back to the box on the firewall. Remove the box cover. Check the big connectors in there.

Check the injector fuses...there are two.

Check the fuse by the battery, it for the ECM.

Do you hear the fuel pump buzz for two seconds when you first turn the key? I know you said you replaced it but if its not connected right it won't work. It has to buzz. This charges the system. Yo may just be getting enough for the prime pulse.

hugie82

As long as you are sure you have oil pressure??? I would spray the fuel in to keep it running. It could be the oil pressure switch, distributor signal, ecm, ect... all of which may start working if you can keep it running a minute or two.

Crossfires are pretty durable and it doesn't take much to keep them going IMO Even though they have a bad rep from years ago when no one had a clue how fuel injection worked

tnovot

You might also want to ask question(s) on the C4 Forum. 1984 used Crossfire as well with an almost identical setup except for air intake. There is a crossfire forum which may be of some help.
I had an '84 with Crossfire and found it to be reliable and fuel efficient when tuned properly. Low performer when compared to today's FI engines but state of the art in its day. Still had plenty of power for me with the manual 4+3 transmission. You have to be or find an old timer to tune it right. New techs may not have even heard of the Crossfire TBI system.
Terry

JhStephens

Okay all, sorry for the delay. My job and the distance between my home and where the vehicle is currently being stored is making it difficult to find time to work on it.

I've replace the fuel pump as stated above. Also replaced the timing chain and sprockets; and have the car fairly close to time. The day I replaced the timing chain (about a month ago) the injectors worked... When I turn the key, the injectors sprayed once then continued to spray when idling, and even increased in volume when I hit the gas.... now, a month later, I fix a gasket leak on the water pump and when it's all put back together I'm face with my original issue again. The fuel pump will not initiate on its own, but if I manually engage the fuel pump relay (which I've also replaced) then the fuel pump activates and sends fuel.. so I let go of the relay, it stops, I turn on the key, the injectors spray the initial spray (if I don't manually engage the fuel pump relay, this will eventually cease due to lack of fuel), I then attempt to start the car, it keeps cranking but nothing happens since the injectors will now not fire. (Added note, when the fuse in the battery area behind the drivers seat is taken out and put back in with the key turned on, the injectors will spray the initial spray, but still nothing when I try to start the car. Don't know if this means anything or not)

As always, your suggestions would be appreciated -

Also, anything that I should check,, please guide me on how to check that item since I'm still pretty new to all this (such as the oil pressure switch* or sensor*.)

jdp6000

Bizzar problem. It almost sounds electrical. Eliminate the obvious. Check both injector fuses....just replace them actually.

I assume you had to disconnect the wires to the Coolant tmep sensor when you fixed the water pump leak. Maybe a problem in that wiring somewhere. Follow the wires back from the injectors to where they go through the firewall. Open the box on the fire wall. Clean all the big connects. See if that helps.

Make sure the two connectors on the driver side of the distributor are on good and tight, I don't remember which of the two but I know if one is not connected the injectors will not fire. One of those wires sends the distributor pulse signal to the computer which activates the injectors.

As for the oil pressure sensor. If its not working or sensing oil pressure the injectors will not fire. No or low oil pressure signal will shut off the injectors. Look at the guage as you crank....I think you need to hit a minimum of 12-15 psi.

When you replaced the fuel pump did you replace the rubber hose in the tank between the pump and sending unit?? It goes (leaks) and just spills gas out back into the tank. If not enough gas gets to the driver side TBI the regular can not create pressure to send to the injectors. The injectors will not fire if the pressure is below 6 or 7 psi. Its a primative test but the only one I know of short of removing the fuel pump again or buying a fuel pressure test tool. Fill the tank to the neck and see if the problem goes away. this test doesn't always work but its worth the try.

Jim

Jim

Jim

JhStephens

Waking the dead on this one I know... but the issue here ended up being a bad ECU. Replaced and the car ran fine for almost 3 years Now I have new issues in a separate post. lol.