fuel pump on operation. can someone explain
Thread Starter
Instructor
Joined: Nov 2011
Posts: 147
Likes: 0
From: Florida
fuel pump on operation. can someone explain
The car takes a long time to start in the morning.
Then after the first start it is great.
No real leak down during the day only if it sits for 12+ hours.
When I turn the key to the run position several times I am not hearing the pump run.
If I go to start it will run and build pressure and then start and continue to run after you release the key.
Thanks
gary
Then after the first start it is great.
No real leak down during the day only if it sits for 12+ hours.
When I turn the key to the run position several times I am not hearing the pump run.
If I go to start it will run and build pressure and then start and continue to run after you release the key.
Thanks
gary
Le Mans Master
Joined: Jan 2006
Posts: 5,621
Likes: 206
From: Orlando FL
If you suspect fuel, put a fuel pressure gauge on it.
Put a meter on the voltage input to the pump. Then you can determine if the pump is getting voltage. If it does and it does not run, the pump is probably bad.
But on that year car the biggest thing that leaps out off the paper at me is injectors. I hear more complaints about running, starting and idling. After the injectors are replaced people say it's like a new engine.
Injectors may not be the problem but something to consider.
Does the 86 have a cold start injector?? Maybe is does not work properly properly.
Put a meter on the voltage input to the pump. Then you can determine if the pump is getting voltage. If it does and it does not run, the pump is probably bad.
But on that year car the biggest thing that leaps out off the paper at me is injectors. I hear more complaints about running, starting and idling. After the injectors are replaced people say it's like a new engine.
Injectors may not be the problem but something to consider.
Does the 86 have a cold start injector?? Maybe is does not work properly properly.
Last edited by pcolt94; Jan 1, 2014 at 07:41 PM.
Safety Car
Joined: Jan 2004
Posts: 3,556
Likes: 13
If the relay is faulty you will not get the 2 sec prime and have to wait until the oil pressure switch operates to power the pump once
you crank the engine over
As the switch and relay are wired in parallel , the pump may only be running off the OP switch alone .
The residual pressure held in the rails allows a instant start after the 1st long crank to build pressure
Thread Starter
Instructor
Joined: Nov 2011
Posts: 147
Likes: 0
From: Florida
Exactly what I was looking for, Thanks
If the relay is faulty you will not get the 2 sec prime and have to wait until the oil pressure switch operates to power the pump once
you crank the engine over
As the switch and relay are wired in parallel , the pump may only be running off the OP switch alone .
The residual pressure held in the rails allows a instant start after the 1st long crank to build pressure
