87 corvette conv.
Thread Starter
Heel & Toe
Joined: Jun 2013
Posts: 19
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From: Lexington ky
87 corvette conv.
I have replaced the fuel pump, fuel relay, filter and car still won't start. Checked the plug and has lots of spark. Going to check the fuel pressure tomorrow. Has anyone had the fuel injector regulator cause the car to not start. It will hit once and after that it just cranks.
Race Director
Joined: Dec 2000
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From: El Paso Texas
You replaced all of these parts BEFORE checking your fuel pressure? Yes, a bad regulator can cause a no-start condition, but test your fuel pressure before carpet bombing it with parts. Troubleshoot, don't guess.
Race Director
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Thread Starter
Heel & Toe
Joined: Jun 2013
Posts: 19
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From: Lexington ky
87 corvette conv.
You're right I should have checked the fuel pressure first. Didn't have the gages available and thought these were the most likely culprits with 94000 miles. The cars sits a lot and sometimes it would start and run like new then other times it just turns over and won't start. I also noticed when I checked on the regulators that you get a diaphragm kit instead of the whole regulator. I understand these are set for the proper pressure at the factory and don't take the top off. Thanks for your answer.
Jim
Jim
Race Director
Joined: Apr 2002
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From: Anaheim CA
There is no adjustment. If you want to replace just the diaphragm you will need a "security" Torx T-10 bit to get the cover off.
Thread Starter
Heel & Toe
Joined: Jun 2013
Posts: 19
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From: Lexington ky
None of the parts stores here had the complete regulator just the diaphragm. Just wondering since the car won't start will the fuel pressure show up on the gages while it isn't running.
Le Mans Master
Joined: Sep 2009
Posts: 6,332
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From: Vermilion OH
the system is pressurized even with the engine not running. when you turn the key to the "on" position you should hear the fuel pump kick on and it will pressurize the fuel system. you should then be able to check the fuel pressure at the fitting on the fuel rail.
Slingshot
Joined: Dec 2001
Posts: 3,817
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From: Charlotte NC
Start with this test. If you don't hear the pump kick in when your first switch the key on AND you don't have fuel squirting out of the Schrader valve when you press it, you have a pump electrical issue.If this is the case, make sure your fuel pump fuse is not fried AND is properly pushed in and seated.
Next, make sure that you have the wires properly connected on the pump. I had a similar no-start problem once and it turned out that my connecting wires were not properly snapped in place. I seated the connectors properly and it fired right up.
Check it out....
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Race Director
Joined: Apr 2002
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From: Anaheim CA
When you start cranking the engine the fuel pump should come on again and the pressure should come up and stay up. Even if the regulator is in full bypass mode it should have SOME pressure.
Please describe exactly what you did when you measured the fuel pressure.
Slingshot
Joined: Dec 2001
Posts: 3,817
Likes: 24
From: Charlotte NC
Also, keep in mind that the wiring on your Corvette is well over 20 years old and has become somewhat brittle. As such, you might have a broken wire or connector.
Check these things out before you charge off and start changing more parts....
P.
8th Gear
Joined: Oct 2012
Posts: 8
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From: Denver Area Colorado
I had the same problem after replacing the pump in my 86 Pace car. the issue was hard starting, had to crank for 30-45 seconds before starting or no start at all. Turns out not all fuel pumps are the same..... The factory unit had a valve built into it that prevented the fuel pressure from bleeding out via the fuel pump when the car is turned off. A lot of the pumps sold today do not have this valve built in so when the pump pressurizes the system for start-up and turns off all the pressure blows back out via the pump. Also the there is that lil device between the pump and the fuel line ( I forget the name of it) this is very prone to failure also. Go for the Walbro GSS340M 255L/Hr HP pump + Racetronix custom installation kit. This pump has the valve and it eliminates the device between the pump and the fuel line.
Remember.... if the engine's not screaming.... it not running...
Remember.... if the engine's not screaming.... it not running...
Thread Starter
Heel & Toe
Joined: Jun 2013
Posts: 19
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From: Lexington ky
Found out the problem with the occasional no start problem. Had the car towed to a master corvette mechanic here in Lexington, KY. The vat system was bad. You could move the tilt wheel in different positions and cause it to start or not start. He put a by pass kit in the vat system and it works fine. On the way home the brakes started to bleed off sitting at a light. Had a new master cylinder installed last fall. I'm going back to Mopar's never had these type problems. I have a magnum rt with 18k. I have the magnaflow exhaust and k&n air filter set up and 20" inch wheels. This is one of the fastest cars I have ever owned. So I'm going to sell the Vette that has had $15000 invested in restoration from the guy I bought it from. I traded him a 72 Olds 442 that was a big mistake.