how many cranks?
Elite Torch Red Member
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From: Exit 89 GSP,Lakewood,NJ The Land Of Mojo
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Re: how many cranks? (Pete K)
This post will likely get moved to c4-tech.
Le Mans Master
Joined: Dec 2000
Posts: 7,839
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From: San Diego, Ca
Re: how many cranks? (Vett-eight-nine)
Mine was like that new, when cold, and I watched the salesman crank on it forever before I took it for a test ride. Many years later, I replaced the injectors. No more problems.
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Re: how many cranks? (Vett-eight-nine)
The oil pressure switch is a redundent, back up for the fuel pump relay. Unless there are other problems, the oil pressure switch shouldn't contribute to an extended cranking complaint. I would start checking things with a fuel pressure guage. Good luck. and...
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Race Director
Joined: Feb 2004
Posts: 12,517
Likes: 19
Re: how many cranks? (CFI-EFI)
6 times on camara firebird vette this has solved the problem for me. if switch doesn't see enough pressure fuel pump won't run. This saved my motor at the track when my oil bypass valve cracked and blew all the oil out. Motor shut off instantly. :chevy
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Drifting
Joined: Oct 2003
Posts: 1,594
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From: CALGARY ab
Re: how many cranks? (Vett-eight-nine)
I'm a bit surprised by how long I have to crank the engine before it starts (typically a few seconds) and then it fires up.
Is this usual for an '89? :eek:
Is this usual for an '89? :eek:
Race Director
Joined: Feb 2004
Posts: 12,517
Likes: 19
Re: how many cranks? (korvette4u)
The oil pressure switch is a $15 guess. This has fixed it almost every time for me . The next common fix is to change the 2 maf relays on firewall. In 89 they used the TRW relays. These were also problematic. Buy 2 new ac-delco relays part # 14089936. These 2 relays cost $15 for both. If these 2 things don't fix it you could start getting down and dirty troubleshooting. $30 gamble but odds are with you . Good Luck! :D
Burning Brakes
Joined: Apr 2002
Posts: 1,083
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From: Spanish Fork Utah
Re: how many cranks? (CFI-EFI)
The oil pressure switch is a redundent, back up for the fuel pump relay. Unless there are other problems, the oil pressure switch shouldn't contribute to an extended cranking complaint. I would start checking things with a fuel pressure guage. Good luck. and...
RACE ON!!!
RACE ON!!!
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Re: how many cranks? (sspackman)
When you turn the key, the FP is supposed to energize immediately, right?
I'll go through it one more time, for Pete K, sspackman, and anybody else that cares. All of the following can be verified by reading your factory service manual. When the ignition is energized, after having been off for for more than approx 10 seconds, the ECM grounds the fuel pump relay for approx, 2 seconds. It runs the fuel pump to re-pressurize and prime the fuel system. When you start to crank the car, the ECM detects the pulses from the distributor, to know the engine is turning over. It again, grounds the fuel pump relay, which remains the source of current for the fuel pump until the engine is shut off. The oil pressure switch is wired in parallel to the relay. Once mininum oil pressure (3#-5#) is attained, the contacts close and current is available for the fuel pump in a parallel circuit. The current from the oil pressure switch does NOT go through or activate the fuel pump relay. The oil pressure switch is a "back up" to the fuel pump relay. Any engine that died or quit for a lack of fuel, when the oil pressure dropped, either had a defective relay, ECM, or connecting wiring. Good luck. and...
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Race Director
Joined: Sep 2000
Posts: 17,298
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From: The Top of Utah
Re: how many cranks? (Pete K)
You or someone before you may have set it up that way. Mine is. The fuel pump relay took a dump. When it was hot, with thinner oil, it didn't want to start at all. I now have a manual push button for priming purposes. If you have any doubt as to what I've written above, consult your factory manual.
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Instructor
Joined: Nov 2002
Posts: 165
Likes: 0
From: NORTH WALES PA
Re: how many cranks? (sspackman)
Havw the same problem. The diagnosis is that your fuel pressure regulator or the seal in your fuel pump is bad. When not running the fuel doesnt stay in the lines but rather returns to the tank. Check Those. :smash:
Pro
Joined: Sep 2003
Posts: 670
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From: charlotte nc
Re: how many cranks? (RUSS105)
I have the same problem with my 86. I have changed fuel injectors and same problem. I checked Fuel Pressure and it drops rapidly after F pump shuts off. I blocked the return line to the tank. no change. I suspect the Fuel pump check valve. Probably time to change the pump. :cheers: