Cranks 20-30 times before starting

[LIGHTEMUP]

1987 GN, 40K miles. When I bought the car it would take 20 to 30 cranks before it would fire, after it was warmed up, 2-3 cranks and it would start. But if it sits for longer than an hour or so, again...20 cranks to get it going. Once it is started it runs great. It had everything original so I updated the chip, new injectors, plugs, wires, Walbro pump, hotwire kit, cam sensor, oil pressure sensor, crank sensor. It still takes 20-30 cranks to get it going when cold. But.....if I put the jumper on the hotwire kit to manually run the pump and then go to start...2-3 cranks and it fires right up. So, looks like it is not getting enough fuel. Under normal conditions (no jumper), when I turn the key, I can hear the pump prime for a few seconds then shut off. My mechanic checked the fuel pressure and it looked OK....any ideas ???

 

[garyk1970]

1987 GN, 40K miles. When I bought the car it would take 20 to 30 cranks before it would fire, after it was warmed up, 2-3 cranks and it would start. But if it sits for longer than an hour or so, again...20 cranks to get it going. Once it is started it runs great. It had everything original so I updated the chip, new injectors, plugs, wires, Walbro pump, hotwire kit, cam sensor, oil pressure sensor, crank sensor. It still takes 20-30 cranks to get it going when cold. But.....if I put the jumper on the hotwire kit to manually run the pump and then go to start...2-3 cranks and it fires right up. So, looks like it is not getting enough fuel. Under normal conditions (no jumper), when I turn the key, I can hear the pump prime for a few seconds then shut off. My mechanic checked the fuel pressure and it looked OK....any ideas ???

sounds like the fuel pump relay (the oem one on the pass inner fender) is bad and the oil pressure switch is energizing the fuel pump after some oil pressure is monitored....replace the relay.......

 

[tom j]

F/P while cranking?

 

[LIGHTEMUP]

Not sure, I thought that since the pump primed when I turned the ignition on that the relay was giving it power to run while cranking but that's a good question and something I'll check next. If it is not running right away during cranking, is the relay to blame?

 

[pajo]

fuel

it sounds as if is fuel related -- is there a fp gauge on the rail ..

 

[gndrager]

does it hold fuel pressure after u shut it off?

 

[LIGHTEMUP]

There is no fuel pressure gauge on the rail, My mechanic hooked one up once to check it when the car was cold, he said it was fine (45 psi?, I forget what it read). After I shut it off, it holds for awhile but like I said above, beyond a couple hours and it takes 20 cranks to get it going.

 

[LIGHTEMUP]

The sure fire way to get it going is hook the jumper hotwire bypass to run the pump constantly, then it fires right away..every time.

 

[pajo]

fuel

it would be essential for you to install a fp gauge on the rail so you can see the difference between your regular start up and "hot wire"..

 

[LIGHTEMUP]

Thanks, good suggestion. I'm also going to "borrow" a relay to see if that solves the problem.

 

[mtocrs1]

pump isolator

If I was a betting man I would put my money on the fuel pump isolator in the tank. They let the pump lose their prime.

 

[bison]

Thanks, good suggestion. I'm also going to "borrow" a relay to see if that solves the problem.

Just turn the key on and send 12v to the fuel pump test lead. Its the grey one behind the alternator coming out of the corner of the harness on the left side valve cover. If it starts after you prime it for a few seconds its def a relay problem

 

[vacuum 6]

If I was a betting man I would put my money on the fuel pump isolator in the tank. They let the pump lose their prime.

Agree. If you don’t have an isolator then the tube/clamp came loose.

 

[joe_schindler]

Doesn’t the computer reset after a certain number of start attempts (to reset the trouble code)? What is that number?

 

[vacuum 6]

I dont think so...maybe this will help ya http://www.gnttype.org/maint/malf.html

 

[LIGHTEMUP]

Yep, that was it...bad fuel pump relay. Replaced it and now she fires right away, every time. Thanks everyone for all your help !!

 

[garyk1970]