1984 Corvette no fuel problem
 

Stored car for the Winter and it was fine. Took it out and it wouldn't start...no fuel being injected, and it had 3/4 of a tank. Checked fuses...OK.....A friend came over and helped change the fuel pump. It turns out the other was fine, so it looked like a electrical problem. He started testing the assembly and touched the wrong wire when testing the sending unit and zapped it. Now the gauge reads full all the time...finally started pulling fuses again and had noticed the injector fuses looked a little oxidized...I took some emery cloth and cleaned them up and the car started....I drove it to my driveway, shut it off and later tried to start it and no fuel again. Went to the auto parts store on Tuesday and bought new 3 amp fuses and replaced them. Car was running again and I was checking tranny fluid because there was a leak during the Winter. While testing the car died......wouldn't start. I left the door open so the sun couild shine on fuse box but still wouldn't start....This morning the car started and I ran it for about 15 minutes then shut it off...I vacuumed it out and went to start it again...no fuel...all day long it just wouldn't start. This morning went out and it started up ok. Shut it off and won't start all day...No fuel being injected. Do you think the zapped sending unit may have something to do with this problem? Also, will a sending unit from a 1991 C4 work in my 84? Thanks for any help someone can give me.

Wait til our resident dawg chimes in. Frizzie is our "Crossfire Expert" and right after he solves your problem, it'll only cost you a small bag of kibble and bits:D

Just a couple things untill the dawg arrives. Did you replace the fuel sock when you replaced the fuel pump? Have you checked the in-line fuel filter under the passenger-side floor pan? Have you tried tapping the fuel pump relay while it is trying to start?

Leaving work now....will post reply when I get home.

Intermittent problems are the worst....

Soooo....that being said, what I need to know is this: During a no-start event, is this an issue of insufficient fuel pressure due to a fuel flow problem, or is it an electrical issue that the ECM is not firing (ie...grounding) the injectors? You will have to troubleshoot it during an event....

First thing to do is measure fuel pressure during an event. Not simple on a TBI setup, but not difficult...just takes some setup beforehand. You will need a low pressure (preferably 0-15 psi) gauge, some rubber fuel injection line, and a "T" fitting. You will find the fuel lines running under the passenger side. By the front wheel, you'll see the fuel filter. Attach a T fitting in the PRESSURE (larger) line just forward of the filter, and run this line to your gauge.

You can also have a fitting welded into the crossover tube between the throttle bodies. I did this and had a corresponding fitting put on my low pressure gauge. Cost $30....BEST mod I ever did....made checking fuel pressure a snap.

http://forums.corvetteforum.com/pict...ictureid=43935

You should get 9-13 psi at key on without cranking the engine. Unlike a port injected motor, fuel pressure on a Crossfire should fall to zero immediately after the 2 second prime signal from the ECM. This is normal. If you don't get any fuel pressure, run a 12V wire from the + terminal on the battery to terminal G on the ALDL connector....

http://www.neilkline.com/Tech%20Tips/images/alcl.gif


this energizes the fuel pump full time. Now tell me what you have on your gauge. If you still have zero, we have a flow problem....pump or wiring.....if you have fuel pressure (9-13) but no injector pulse, we have an electrical problem, probably ECM related......but we'll cross that bridge if / when we get to it.

Check it out and report back. This one should be an easy fix.:cheers:

I didn't check out the filter because the car has side pipes and impossible to get under at home....No didn't replace the sock but the old one looked good....I have to locate the relay and try that. This morning...AGAIN, I cranked it and it started right up....When it was shut off, it would not start all day long....Thanks

Hi Frizlefrak, Haven't been able to try your fix yet, it will be difficult for me especailly since I have Rheumatoid Arthritus. I have a couple of questions for you if you don't mind. Will a Fuel sending unit from a 91 Corvette work on my 84? I was told that there might be a pressure problem.....not sure I understand that, but was wondering since my sending unit was zapped with a 12 volt surge by a friend who was trouble shooting, would that have anything to do with the fuel getting to the injectors? I know it may sound stupid because I thought it only transmitted to the fuel guage, but I thought I would ask....Car wouldn't do its morning startup today...Just turns over and over...Thanks and I appreciate your help...Wayne

Wayne....the sending unit will work just fine. You don't even have to change the pump.....the TPI higher flow pump will work good with your Crossfire. The pressure regulator built into the rear TBI unit will keep it at 13 PSI.

Solved?
 

Hello, was this problem ever solved? I have been working on a 84 xfire with similar issues. Got it out of the barn after winter started right up gave it a bath and drove about 30 miles and it just lost all power. Would start then die couldn't keep it running. Trailered it home checked cap button rotor, they needed replaced so I did and nothing. Cleaned the iac's, nothing. If I feather the throttle fast I can keep it idling, full throttle dies instantly. Any thoughts on my next move? Thanks Darren

This points to a fuel problem more than an ignition problem. Have you checked the fuel pressure before the fuel filter(located under car on passenger side) and after the fuel filter? Should be about 13 to 14 psi.

You must have read post #5. Try following that...

Who are these "strangers" I haven't seen here in quite a long while -cat and dog??? That old rat is always around -- can't even get rid of him with D-Con!
:D

I was amazed when this four-year old thread resurfaced!

And where are these guys with 84's coming from?

BTW, I smoke D-Con every day... :seasix:

And that old rat knows all about pressure. He has buildup everyday and has to release gas!!!
:rofl:

Thanks
 

I was actually surprised my self to see a reply on such an old post. Turns out after checking the fuel pump several times, it was being sneaky! I would check it and have 15 but I finally caught it at 1lb :shots: I have checked almost everything dealing with fuel on this car except (stupid me) the fuel pump. Did find the map is only putting out 2.32v. Anyway thanks for the info I'm sure I'll be visiting the barn often considering I seem to have one of those "problem prome" xfire c4

Good job!! :seasix:

The Crossfire is just a throttle body injection and was first used on the 1982
Collector Edition Corvette. TBI was used for years in GM/Chevy trucks, Astros and
my 1988 S-10 Blazer too. They were /are strong and dependable but as it was new and
replacing carburetors and was managed by a computer, it was treated like a mystery and
gained an unfair rap when inexperienced mechanics dorked it up. 'It's never the mechanic's fault...'

:southpark: