Hey guys I am doing a shout out for some help. My father-in-law just bought a '92 coupe. He lives in Md while I am in AZ so I can't check into this matter first hand but thought to check here.
He says when he first starts the car up he has to turn the key wait 10 secs for the car to start. he can hear fuel pump, then waits and it fires right up. if he does not wait, it will choke and not start. My guess is that he has a defective fuel pump relay but not really familar with the engine. Any help would be appreciated so I can steer him in the right direction before has takes it into a stealership.

Thx,

 

sounds more like a failing fuel pressure regulator or a weak pump.

he really needs to get the Helm Factory Service manual to properly debug this problem.

 

Thx, I going to send him a set for xmas.

 

When was the last time he changed fuel filters?

 

The computer primes the fuel system via the fuel pump relay for 2 seconds. If waiting more than that 2 seconds makes a difference, then it has nothing to do with the fuel pump relay.

RACE ON!!!

 

He just bought the car less than a month ago. It has just over 60K mile on it.

"The computer primes the fuel system via the fuel pump relay for 2 seconds. If waiting more than that 2 seconds makes a difference, then it has nothing to do with the fuel pump relay."

That is why a thought it was the fuel pump. It starts like a champ if he waits 10 secs...I mean without fail but absolutely won't start if he waits less

Thank you for the responses and input

 

I had a similar problem on a 1984 corvette. At cold start, I would have to turn the key for a long time before it would finally start. It was the ECM
Changed the ECM. Works fine now.

 

Reread what you quoted me as saying. Now listen to your response. Your response doesn't make any sense. When the key is turned to "On" the computer activates the fuel pump relay for 2 seconds, which powers the pump for 2 seconds. After 2 seconds, the computer stops energizing the relay. After 2 seconds the pump shuts off. If the car won't start after 2 seconds, but WILL start after 10 seconds, it has nothing to do with the fuel pump or the fuel pump relay, which does nothing in the 8 seconds, in between. Get it?

RACE ON!!!

 

Just so we are all on the same page... Does it take 10 seconds of cranking before it starts? Or it will start right away if he waits 10 seconds to begin cranking? Your statement, "if he does not wait, it will choke and not start." makes it sound as though, if he waits for 10 seconds, before he cranks it, it starts right up WHEN he cranks it. If that is the case, which is how I interpreted it, my 2 second fuel pump comments apply.

RACE ON!!!

 

I haven't done this for awhile...but I will say this, when you first turn the key on it does exactly what CFI stated....everything functioning it runs for 2 seconds. BUT, if you turn the key off right away without cranking, and then turn it back on right away it will NOT immediately run again for the 2 seconds! there is a short time delay, funny, about 10 seconds if I remember right. Could be pump, clogged sock or filter amonst other things. What he really needs to do is get a fuel pressure guage on it.

Sounds like he's having to cyle it twice to get enough fuel to the rail.

 

Again, Thank you.
CGI- got it. Does anyone know of a good mechanic in the Upper Marlbaro, MD (or DC) area that I can send him to?

 

???



That is correct. The key must be "Off" for 10 seconds before turning the key to "On" will start another 20 seconds of priming.



That isn't how I interpret what he wrote. What I read was, if he turns the key to "On" and waits 10 seconds, before cranking, the car starts right up. If he turns the key to "on" and starts cranking right away, it will "choke and not start". If I am reading him correctly, then it is unlikely to be a "pump, clogged sock or filter", because if those items were bad, it would run poorly and have no power, once it was running. That wasn't part of the symptoms. Again, the fuel system (nor anything else I can think of) does anything between the end of the 2 second priming period for the next 8 seconds.

RACE ON!!!

 

???



That is correct. The key must be "Off" for 10 seconds before turning the key to "On" will start another 20 seconds of priming.



That isn't how I interpret what he wrote. What I read was, if he turns the key to "On" and waits 10 seconds, before cranking, the car starts right up. If he turns the key to "on" and starts cranking right away, it will "choke and not start". If I am reading him correctly, then it is unlikely to be a "pump, clogged sock or filter", because if those items were bad, it would run poorly and have no power, once it was running. That wasn't part of the symptoms. Again, the fuel system (nor anything else I can think of) does anything between the end of the 2 second priming period for the next 8 seconds.

RACE ON!!!

 

???



That is correct. The key must be "Off" for 10 seconds before turning the key to "On" will start another 20 seconds of priming.



That isn't how I interpret what he wrote. What I read was, if he turns the key to "On" and waits 10 seconds, before cranking, the car starts right up. If he turns the key to "on" and starts cranking right away, it will "choke and not start". If I am reading him correctly, then it is unlikely to be a "pump, clogged sock or filter", because if those items were bad, it would run poorly and have no power, once it was running. That wasn't part of the symptoms. Again, the fuel system (nor anything else I can think of) does anything between the end of the 2 second priming period for the next 8 seconds.

RACE ON!!!

 

ttt

 

Not sure of a mechanic in that area, but if he has about $40 for a fuel pressure gauge and 30 minutes of time to attach the gauge to the schrader valve on the passenger side of the fuel rail and look things over....then it will shed some light on things.

The ECM energizes the fuel pump relay, which sends 12v (battery voltage) to the fuel pump. After approx 2 seconds the ECM stops engergizing the fuel pump relay therefor the fuel pump stops priming. All this does is deliver fuel to the fuel rail and if everything is working correctly the engine should start on the first or second revolution (quickly).

If he is trying to crank the engine and it will not start, but takes about 10 seconds to start, there is a problem with one of the 4 ingredients to start an engine (spark, fuel, air, compression). I'm banking on a fuel delivery problem here. A fuel pressure gauge will help troubleshoot. See if the fuel pressure builds to normal (~45 psi) when the key is turned on. See if the fuel pressure bleeds off quickly after the initial 2 seconds when the fuel pump has stopped. If the pressure holds, I would be inclined to test the injectors or use a timing light to check for spark. If the pressure bleeds off quickly, there is a leak in the system that needs to be systematicaly traced. There are about 8 different spots in the fuel system that fuel can leak from.