I have stock 1990 EFI. When I crank it over it takes about 10 to 15 seconds for the motor to start up and then I have to pump it once or most times twice, then it starts. I have a single carb 350 in my other car takes less than 4 seconds to start. Any ideas on why I have to pump the EFI motor a couple of times before it will start? :stupid: :stupid:

There is no gas being pumped with an EFI engine. How many miles on your car? Has it ever been tuned up?

I have stock 1990 EFI. When I crank it over it takes about 10 to 15 seconds for the motor to start up and then I have to pump it once or most times twice, then it starts. I have a single carb 350 in my other car takes less than 4 seconds to start. Any ideas on why I have to pump the EFI motor a couple of times before it will start? :stupid: :stupid:

Turn your key to the on position and wait about 10-15 seconds, don't crank it. After 10-15 seconds crank it, is it still hard to start or does it turn over right away?

I have to usually wait about 10 seconds before I start my car, because (and correct me if I'm wrong) the fuel rails have to pressurize before the car will start properly.

There is no gas being pumped with an EFI engine. How many miles on your car? Has it ever been tuned up?

76,009 miles. I don't know we pick it up about a year ago. I do have the owner's manual, I check it.

Turn your key to the on position and wait about 10-15 seconds, don't crank it. After 10-15 seconds crank it, is it still hard to start or does it turn over right away?

I have to usually wait about 10 seconds before I start my car, because (and correct me if I'm wrong) the fuel rails have to pressurize before the car will start properly.

I did what you said. It started within 3 seconds without giving it any gas. Is there a one way valve available? Now I took it out for a ride and made several stops. At each one it took a little longer till it went back to about 15 seconds. On the last stop I pumped it 4 or 5 times and it started right up. Any ideas.
:banana:

On the last stop I pumped it 4 or 5 times and it started right up.


As fuel injected cars have NO acellerator pump, pumping the gas pedal does nothing at all (other than wearing out your right leg). And when you turn your key on, your fuel pump quits pumping exactly 2 seconds later. It's a safety feature that is built in to prevent horrific fires in the event of a wreck.

As fuel injected cars have NO acellerator pump, pumping the gas pedal does nothing at all (other than wearing out your right leg). And when you turn your key on, your fuel pump quits pumping exactly 2 seconds later. It's a safety feature that is built in to prevent horrific fires in the event of a wreck.
Makes sense. I have noticed that when I have hit the gas pedal it seemed to start quicker and my wife had said the same thing when she drove it. Coincidence?? Am I letting trapped gas get into the cylinders?

The only thing pumping the gas might affect is a glitchy throttle position sensor.

pumping the gas pedal does nothing at all

On a TPI CAR pumping the gas SHUTS off the injectors.
If the TPS V is over a certain figure while cranking the ECM thinks you are trying to clear a flooded engine and cuts off injector pulse.
I suggest his injectors are leaking down , flooding the engine which is cleared by him hitting the throttle which allows extra air in to dilute fuel and shuts down the injectors.
Does it start the same ; Hot v Cold start?

When I crank it over it takes about 10 to 15 seconds for the motor to start up and

Can you hear the fuel pump prime for 2 sec?
If the pump doesn't prime the rails , you have to crank until you have 4 psi engine oil pressure to close the oil pressure switch that turns on the fuel pump

On a TPI CAR pumping the gas SHUTS off the injectors.
If the TPS V is over a certain figure while cranking the ECM thinks you are trying to clear a flooded engine and cuts off injector pulse.
I suggest his injectors are leaking down , flooding the engine which is cleared by him hitting the throttle which allows extra air in to dilute fuel and shuts down the injectors.
Does it start the same ; Hot v Cold start?

:thumbsup3: :goodpost: Think you pretty well described it.

On a TPI CAR pumping the gas SHUTS off the injectors.
If the TPS V is over a certain figure while cranking the ECM thinks you are trying to clear a flooded engine and cuts off injector pulse.
I suggest his injectors are leaking down , flooding the engine which is cleared by him hitting the throttle which allows extra air in to dilute fuel and shuts down the injectors.
Does it start the same ; Hot v Cold start?

It seems to start a little quicker when it is cold. Some times it starts fine for a couple days then it gives me a little bit of a problem for a few days then clears, sort of cycle

On a TPI CAR pumping the gas SHUTS off the injectors.
If the TPS V is over a certain figure while cranking the ECM thinks you are trying to clear a flooded engine and cuts off injector pulse.
I suggest his injectors are leaking down , flooding the engine which is cleared by him hitting the throttle which allows extra air in to dilute fuel and shuts down the injectors.
Does it start the same ; Hot v Cold start?

If the injectors are leaking what does this mean as far as stopping them? New ones? Would the spark plugs be black?

On a TPI CAR pumping the gas SHUTS off the injectors.
If the TPS V is over a certain figure while cranking the ECM thinks you are trying to clear a flooded engine and cuts off injector pulse.
I suggest his injectors are leaking down , flooding the engine which is cleared by him hitting the throttle which allows extra air in to dilute fuel and shuts down the injectors.
Does it start the same ; Hot v Cold start?....

Can you hear the fuel pump prime for 2 sec?
If the pump doesn't prime the rails , you have to crank until you have 4 psi engine oil pressure to close the oil pressure switch that turns on the fuel pump

Vetteoz is on the right track here. If you want to get to the root of the problem, you need to go down the diagnostic road that he is starting down, by asking you the questions that he has asked. Answer those questions...he will take you from there.

I am not confusing the issue by interfering...only wanted to point out that he is on the right track with diagnosing your issue.

Can you hear the fuel pump prime for 2 sec?
If the pump doesn't prime the rails , you have to crank until you have 4 psi engine oil pressure to close the oil pressure switch that turns on the fuel pump

I have not heard the pump, but I should open the hood to do that. So it won't start up without some oil pressure, interesting and complicating. So the problem could be that the fuel pump is not pumping right away? Or is this idea stupid :stupid:?

So the problem could be that the fuel pump is not pumping right away? Or is this idea stupid

Correct
Read this start up sequence.
http://www.corvetteactioncenter.com/tech/howto/idx.php/0/016/article/

Pump primes for 2 sec , then stops.Rail is pressurised. Injectors not pulsed until ECM sees signal from oil pressure switch closing @4psi.
In relation to your original question; it is possible you are not getting the fuel pump prime and are having to wait until engine has 4 psi before the pump comes online.
Check out the fuel pump relay and connections.
If the relay is faulty, the engine will still run because pump is powered from OP switch in parallel as a backup to the relay

I suggest you hook a pressure gauge to your fuel rail. Then turn your key on and see how long it takes to pressurize to 55 psi. It should take no more than one second or so. Then start cranking your engine and see if your pressure stays at 55 psi. If it stays at 55 psi while cranking, then you must have an ignition problem.

Personaly the first place i would start would be to get a pressure reading off the fuel pressure rail to see if you have a weak pump or clogged filter. I'm wanting to say you should have around 42-45psi with the engine running. Now the second thing i would do is when the engine is running is to pull the vacume line from the pressure regulator and see if the fuel pressure jumps up around 10 more psi. If it does the regulator is working and will allow more fuel pressure to the injectors. Now put the vacume line back on. While the engine is running smack the throttle and see where the pressure goes. When you hit the throttle the fuel pressure should jump up around 5-10psi more. If not then a weak pump or pressure reg may be going bad. The distrib also works the start-up inj pulse. You can also "dead head" off the main fuel line before the filter to check fuel pump pressure. It should be around 100psi give or take. Now the psi pressure i have given you are ball park off my head as i mess with alot of inj systems and can't remember all the numbers for evey car truck and what have you. So check the manual or online! This is the place i would start first. Let us know what you find out if you do this. Good luck.

Then turn your key on and see how long it takes to pressurize to 55 psi. .

43lb on TPI with vac line disconnected

If it stays at 55 psi while cranking, then you must have an ignition problem.

No.
Is possible to have correct fuel pressure at rail but if the injectors are not pulsing for whatever reason then there will be no fuel supplied to engine.
It's not like a carby car where pressure at the carb is enough.

You can also "dead head" off the main fuel line before the filter to check fuel pump pressure. It should be around 100psi give or take.

Why would the pressure before the filter be any more than pressure at fuel rail? Pump pressurises from tank to rail ; regulator bleeds off excess, pressure. So everything upstream of the reg should be near enough same pressure unless filter is blocked.

On a TPI CAR pumping the gas SHUTS off the injectors.
If the TPS V is over a certain figure while cranking the ECM thinks you are trying to clear a flooded engine and cuts off injector pulse.
I suggest his injectors are leaking down , flooding the engine which is cleared by him hitting the throttle which allows extra air in to dilute fuel and shuts down the injectors.
Does it start the same ; Hot v Cold start?

Most of the time yes, Sometimes it does start up pretty quickly hot or cold.

You need to confirm fuel pump operation when you first turn the key to "ON" w/o cranking the engine. You don't need the hood open. The pump is in the tank (in the back) and if it's quiet around you and the car, when you turn the key to "ON", you can (or should) hear the pump run for ~2 seconds. Please check this and report back so we can move forward with the diagnosis...and repair.

If your car is very slow starting, you MAY have a very plugged up sock on the fuel pump, or you MAY have a very plugged up fuel filter. If I recall, your fuel pump should deliver around 42 gph at free flow. That would be about 7/10ths of a gallon per minute. Hook up a fuel line to your return line (at the frame connection), pump it into a gallon can, and see how long it takes to pump in 7/10ths of a gallon..

If your car is very slow starting, you MAY have a very plugged up sock on the fuel pump, or you MAY have a very plugged up fuel filter. If I recall, your fuel pump should deliver around 42 gph at free flow. That would be about 7/10ths of a gallon per minute. Hook up a fuel line to your return line (at the frame connection), pump it into a gallon can, and see how long it takes to pump in 7/10ths of a gallon..

Why 7/10ths? Why not a gallon?

Why 7/10ths? Why not a gallon?

If you hadn't failed Maths 101;
you would understand 1 gal/ min is 60 gal/ hour!

Personaly the first place i would start would be to get a pressure reading off the fuel pressure rail to see if you have a weak pump or clogged filter. I'm wanting to say you should have around 42-45psi with the engine running. Now the second thing i would do is when the engine is running is to pull the vacume line from the pressure regulator and see if the fuel pressure jumps up around 10 more psi. If it does the regulator is working and will allow more fuel pressure to the injectors. Now put the vacume line back on. While the engine is running smack the throttle and see where the pressure goes. When you hit the throttle the fuel pressure should jump up around 5-10psi more. If not then a weak pump or pressure reg may be going bad. The distrib also works the start-up inj pulse. You can also "dead head" off the main fuel line before the filter to check fuel pump pressure. It should be around 100psi give or take. Now the psi pressure i have given you are ball park off my head as i mess with alot of inj systems and can't remember all the numbers for evey car truck and what have you. So check the manual or online! This is the place i would start first. Let us know what you find out if you do this. Good luck.

I don't have a fuel pressure gauge nor a diagnostic tool. I do appreciate the help but I think it is best to take this to a certified Chrysler mechanic that I know. He loves Fords so he gives me a hard time on about my Vette and my SBC powered 1929. I think it is this weekend he is drag racing at an all Ford weekend. I told him that they have these all Ford weekends cause that the only thing a Ford can beat is another Ford.
When I get an answer I will post it.