Alright,

My 87 GTA, 355 TPI has quite rapidly developed the problem of wanting to crank forever before it fires up, this happens in the mornings after it has sat over night, and after the car has sat for a couple hours.

When the car is warm and has been run for a little bit it fires right up no matter what, it's just when it has had time to sit is when it decides it doesn't wanna fire up too quickly.

Everything on this motor has been replaced, except for the distributor, you name it, and i've probably replaced it...

The only thing i've noticed is that sometimes my fuel pump likes to keep running for a lot longer than a couple seconds after I turn the car off (or stop cranking), other than that it runs smooth as glass while warmed up and running.

This is the second new fuel pump that's been put on this car in a matter of a couple years, the pump primes itself up everytime i turn the key right before I start it.

It's almost like the car isn't getting any fuel, but hell who knows, i'm no mechanic, I just want my car to fire up on the spot!

Any suggestions would be greatly appreciated

 

I have the same issue with my 88 iroc, the l98 cranks, but I have to pump the accelerator for it to start

 

Check your fuel pump relay. The stock system is set up so that if the relay is bad, the relay is bypassed as soon as oil pressure is achieved. It'll usually take cranking the engine for about 30-45 seconds for the engine to fire with a bad relay.

 

Pumping the throttle on a EFI cuts off fuel while cranking; there is no accel pump like on a carb.
What you are doing is clearing a overly rich condition ; possibly from leaking injectors

 

If pump is priming ;key on , then you need to put a pressure gauge on the fuel rail and see if the rail pressure is holding.
The pressure might be leaking down so the rail is not pressurized while cranking until the oil pressure switch runs the fuel pump again

 

It happens to me as well. The problem is the IAC sometimes does'nt open while cranking. If you crack the throttle open while cranking the car will start. Once it starts you may have to hold the throttle slightly while the car warms over. At some point the Iac should open and take over. I've had this happen a lot but it seems to be intermittent.

 

Pumping (well holding down 1/3 gives it more fuel)
holding it to the floor puts ecm in clear flood mode..

sounds like a FP relay or FP pump check valve, leaky inj or bad FPSI regulator..

 

Alright, here's an update.

Today when I went to start my car after sitting overnight, I did something a little different...

I primed the car 4 times, instead of the usual once right before I fire it up.

The car still took alot longer than normal to fire up, but it did fire up a WHOLE lot faster than when I let the car prime up only once.

My guess is that my fuel pressure isn't holding up, am I warm? Maybe?

 

IAC has no effect on startup.
As noted above ,once TPS reading goes above certain value the ECM cuts off fuel.If your engine starts with foot on throttle then you have too much fuel in intake which is the opposite of the OP's problem.

 

There are tests to do using a pressure gauge where you clamp the various fuel lines to determine if the pressure leakdown is on the supply side ( check valve ) or return side (FPR ) .
If your injector(s) were leaking down I suspect you would have the rich start problem mentioned by the others above where you would need the throttle open to start
You say you hear the pump prime , a gauge would confirm if it is and at what pressure

 

cold start valve have anything to do with it?

 

Hello quisterio!!

Sounds like a fuel pressure issue, first test fuel pump pressure, making sure that the pump is delivering the right pressure, and that it is not losing pressure over time. Test the fuel pressure regulator also, and check all lines for collapse/obstructions. Check / replace the fuel filter, amazing what a dirty fuel filter can do. Check all relays, and wiring. You should be able to pin point your problem.

As a side note, my son had his fourth gen Camaro have the same issue, however, the stealership said it was the MAF being dirty, using a K & N "over" oiled air filter. After they "cleaned" it, it still did the same thing. Found out that the plug gap was way off, about double the required gap, once the plugs were regapped to the proper gap, all starting issues miraculously disapppeared!!

 

I don't know, but for me holding the throttle slighty cracked open fires the car up immediately. I only do it when the car won't fire up while cranking. It only happens once in a while, but you can clearly hear when the IAC is operating. There is a loud whistling sound when it is open. I know my fuel pressure is good because i have a gauge installed. I could be wrong, but if the IAC does'nt open while cranking, the motor won't fire up. It works for me.

 

Hello 73duster!!

For me, on the first morning start, I turn the key to the on position, fuel pump primes, then I turn the key to the start position, engine starts instantaneously!!! No pumping ever, and my car is 23 years old!!! Same fuel pump, same IAC, same MAF, etc!!!

Cleaning, and setting up the IAC valve properly is crucial to a good starting, and running engine, as well as adjusting the TPS to the correct voltage!!



Fuel injected motors don't need to be pumped in order to start, if you pump it, it will flood, and then you'll have to hold the throttle to the floor while cranking, in order to clear the flooded condition!!

 

Well mine cranks and once you pump the gas like once or twice it will start like normal, I am going to run seafoam through my system and replace the old fuel filter and spark plugs soon hopefully that fixes it, because when I bought it(October 09) it would start as soon as you turned the key, but after some time it started to do wat it's doing

 

Hello 88 5.7 Iroc-Z!!

I have heard about some corrosion in the fuel pump connector located up by the fuel tank causing problems before. However, I don't recall the exact problem that was encountered, be it a total failure, or just an intermittent problem. It might be worth it, to check it out, and apply some "electical connector grease" not sure of the actual name, but it protects the connections from water, and salt corrosion, and it looks like peanut butter!!



I believe di-electric grease would do the same job, as the above mentioned peanut butter looking stuff, for all I know it probably was the same stuff, just a different colour!!!

 

If he had a carb .
With EFI there is NO accelerator pump to squirt gas in so you can "pump " as much as you like As noted above , anybody with EFI that has to pump the throttle to start their engine has a rich condition from fuel leaking in somewhere

If runs fine after it starts so it is not a filter problem

 

fuel pump check valve is probably leaking. Use a screwdriver to check the rail pressure at the schrader valve before you turn the key on in the morning. if there is no pressure then you found your problem.



When you first turn the key to the on position the ECM pulses the injectors once. That's the pump shot that helps the engine fire up. If there is no rail pressure then you won't get any fuel down into the runners and it'll take longer to start.

 

Well folks....

Today I went out and did the same exact start-up procedure that I did before... It took a while but it started.. I went out somewhere, came back later and parked it...

An hour later when I went out to drive somewhere else, it wouldn't start.. No matter how long it cranked or anything, not even a hiccup...

My fuel pump primes up damn near every time right before I try to crank it, and it continues to run a little bit right after I stop cranking..

I am now stuck with an inoperable car in my apartment complex's parking lot, 2 hours away from home at college, this blows big time... Something on the car has finally given out and needs to be replaced...

I am currently in class as I type this, as soon as I get out of class I am going to switch out the fuel pump relay with a brand new one and pray it works. That's all I got to work with in the dark and freezing cold lol... When it's light I plan to take a good look at the harness under the car just for giggles to see if there's anything needing attention on it.

 

Hello vetteoz!!!

Check out the starting procedure for TPI engine codes "F" and "8" on page 2-12, and 2-13 in the 1987 Camaro Owners manual.

It states on page 2-13 "Cold or Warm engine - Do not push down on the accelerator pedal. With your foot off the pedal, crank the engine by turning the ignition key to "start". Release the key when engine starts.

If the engine does not start after 3 seconds of cranking, push down the accelerator pedal to 1/3 of it's travel while cranking. Release the key (and accelerator pedal)
when the engine starts.

If you tried the Cold or Warm Engine starting procedure and the engine still does not start, push the accelerator pedal down to the floor and hold it there while cranking the engine. This should clear the engine if it is flooded."



My sister-in-law would 9 times out of 10, flood my 1989 Chey 4.3L TBI S-10. She wouldn't get it through her head that you don't need to play with the throttle while starting. She did it in my drive way once, and I showed her how to clear it, by holding it to the floor while cranking, once that was done, all she had to do was turn the key!!! She finally got it!! I owned that truck for 9 years, and for my wife, and I, it always started without touching the throttle, first time everytime!!

 

Hello quisterio!!

Purple82TA has an idea to test the schrader valve on the fuel rail first thing in the morning, while your doing that, have a look at the ignition coil connections. Any wires not connected/loose? It's a stab in the dark, but you never know until you look!!

 

Are you talking about the Cold-Start Valve??

Also, should there be pressure at the rail after it has sat overnight??

Anyways...

Well, right now the car is covered in about 6 inches of snow, so I'll wait to pop the hood for today...

Last night though, I switched out my fuel pump relay with a new one, and while the car did take a little longer than usual to fire up, it did in fact FIRE UP and run just like it should...

I will post back here as soon as I can with my findings after I test the schrader valve, and while I'm doing that I'm gonna check the crank fuse under my dash to see if it's still alive, maybe my cold start injector isn't firing on startup?