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Car is a 1986. I did a lot of work to it and it ran great. Long story short, had no keys to start it for close to 4 years. Locksmith wanted too much, so I switched out the ignition key cylinder, and bypassed VATS. Pumped out the old gas, and put fresh stuff in there. Car cranks, but does not start.
When I went through resistors to find the right one, I said to myself: "You'll know which one it is when you hear the fuel pump prime". Kit came with 17 resistors...14th attempt was the one, but never heard the fuel pump prime, so looking like that's where my problem is. Going to test for fuel at the rail right now.
Is there a procedure to test circuit...fuse, relay, etc.? After pulling that neck out of the tank of these cars enough, I've seen what they look like when fuel has been in them for years, and guessing the pump itself is probably corroded/rusted etc., but want to test the other stuff first.
I'm a novice, but patient and determined. I do best with simple terms like "put red probe to contact of third terminal from the left, and black probe to bare metal". Just being honest...sometimes the lingo throws me off.
Surprisingly, I am getting fuel pressure at the schraeder valve on the rail. First crank, I got out to look at it it after cranking, and it was at about 20 psi. Second try, I faced the gauge towards the window as best I could, and it looked to spike to about 35psi during initial crank, then dropped down to about 20psi while still cranking. After cranking, it seems to be slowly lowering from 20psi. Any thoughts?
Last edited by racerseks; Aug 18, 2022 at 07:20 PM.
Thankfully the FPs were designed to replace with ease.
This appears to be a classic weak FP.
It could be the diaphragm, filter. Possibly FPR.
Good idea to Ohm out the INJs to make sure they match.
Thankfully the FPs were designed to replace with ease.
This appears to be a classic weak FP.
It could be the diaphragm, filter. Possibly FPR.
Good idea to Ohm out the INJs to make sure they match.
That's what I figured, so I went ahead and ordered a new fuel pump. Ifit turns out to be something else, I'll have a spare. All three of my cars use that same pump anyway, and cost was minimal.
Is there any procedure to testwhatyou'vem,entionedin thew meantime?
That was my guess, and I ordered a pump. Do the pressure readings I get make sense? Also, I tried a test light on one of the cylinders, and it doesn't light up, so maybe I am not getting spark. I plan to test it again today, but I tried the same light on my truck, and it does work...
Know of any step by step "No start" diagnosis procedures? I've done some digging onjhere, but haven't come across quite what I am looking for...
Thankfully the FPs were designed to replace with ease.
This appears to be a classic weak FP.
It could be the diaphragm, filter. Possibly FPR.
Good idea to Ohm out the INJs to make sure they match.
Thanks for your reply. Can you point me in the right direction on how to test the injectors. They are FIC's, with about 40 miles on them...but been sitting a while...
I changed out my fuel pump, but no luck. I could have gotten a bad one I suppose. Can someone direct me to that "pinch the return line" test, and will that tell me whether or not the pump is bad?
I can never hear that pump because I am the only one to turn the key and my ears are as full of c*** as I am. Be advised the fuel pump relay between the windshield wiper motor and the master cylinder is bypassed by oil pressure. The fuel pump can and will also be turned on by the oil pressure switch as the engine turns over. There is a 2 wire oil pressure switch ( and the oil pressure sender with one wire) between the distributor and wiper motor that bypasses the fuel pump relay as a second path for fuel pump power. So with oil pressure you will have back up power to the pump. That 2 wire oil switch is also responsible for a lot (many many) corvette oil leaks.
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Last edited by Vets-Vet; Aug 29, 2022 at 07:30 AM.
Hello, and thanks for your reply. I went ahead and bought both oil pressure switch and sensor...but the pressure drops immediately, before I ever even get a chance to crank it. Could either of these still be the culprit?
Last edited by racerseks; Aug 28, 2022 at 03:36 PM.
I would not think so, the switch is just a path for back up power. In order to replace those two you will have to remove the windshield wiper motor and when you pull it out it gets stuck and then most people yank it and break the case on the windshield wiper. The guys at Mirrok corvette told me it is best to unbolt the arm attached to the motor but I don't think most of us try that. we remove the arms from the wipers and try to manuever the short 3 inch arm on the motor out of the hole which is tough at best.
Fellow member with the same type of problem, do not confuse fuel pump regulator with fuel pressure regulator. What they are talking about is the fuel pressure leaking back into the tank, or the fuel injectors leaking the pressure. Has a procedure of building pressure and pinching off hoses to find leak,
Fellow member with the same type of problem, do not confuse fuel pump regulator with fuel pressure regulator. What they are talking about is the fuel pressure leaking back into the tank, or the fuel injectors leaking the pressure.
What I was trying to say about the oil switch is that a bad fuel pump relay can be overcome by the oil pressure switch providing the second path for fuel pump power.
1986 Fuel pump troubleshooting...
