Weird starting issues?

[88gtman]

My 94 Firebird with the 3.4L is having some strange starting issues. When the car has been sitting for more than 30 min. or so it has a hard time starting. Usually it will not start on the first crank. Most of the time it will start on the second try and occasionally I will have to try a third try. Once it has started it runs fine. No signs of any kinds of problems, no codes. I have removed the EGR Valve cleaned it good and put it back. I have replaced the fuel filter. I can here the fuel pump come on whenever I put the key in the on position. The vaccum lines on the fuel pressure regulator don't show any signs of leaking and when I take the vaccum line off of the regulator there is no sign of fuel in the vacuum line. The engine turns over real strong when I try to crank it, so I don't think it is an electrical or starter problem. Any ideas?

PS. I do not have a fuel pressure gauge, but when the car is turned to the on position and I press down on the fuel pressure test valve the fuel comes out pretty strong so I know it must be getting some fuel pressure. Not sure how much though.

[nascar24jd]

Re: Weird starting issues?

Try to crack the throttle open slightly and see if it starts better then. Might be a clogged IAC valve.

My 93 used to do that once in a while and that was the problem. Cleaned it out with some good spray cleaner and never happened again.

[88gtman]

Re: Weird starting issues?

I just cleaned that recently. I am pretty sure that is not the problem. I just talked to my mechanic and he said that more than likely it is the pump wearing out or the "sock" filter is clogged up in the tank. He said he won't know for sure until he runs some tests. I am just going to drop it off with him. It could very well be my pump wearing out. I have 181,000 miles on my bird and I believe that it is still on the original pump.

[cam98aro]

Re: Weird starting issues?

i highly doubt it is the fuel pump

[Rob Bell]

Re: Weird starting issues?

I would still suspect the regulator. The gas-in-the-vacuum-line test only confirms the regulator is bad. Lack of gas does not necessarily mean the regulator is good. The hard starting is very symptomatic of a leaking regulator.

Let's see what the mechanic says.........

[88gtman]

Re: Weird starting issues?

I would still suspect the regulator. The gas-in-the-vacuum-line test only confirms the regulator is bad. Lack of gas does not necessarily mean the regulator is good. The hard starting is very symptomatic of a leaking regulator.

Let's see what the mechanic says.........

First of all, I just want to clarify that I have known my mechanic my whole life. He has been in the business a loooooong time and knows what he is talking about. Second, I said that there was NO fuel in the vacuum line. Third, my mechanic said that he would have to run some test to know what the problem is for sure. He said that it could possibly be the regulator, but it is highly unlikely due to the fact that it is rare that he comes across a bad one. He is simply helping me make sure that we know exactly what is causing the problem before I go throwing money into buying parts and such. So know definitive answer on the cause as of yet. I am going out of town for the week and he is working on it while I am gone. I will let you guys know what he finds out. If it is the pump then I am going to go ahead and let him change it because I don't have the time nor the welding tools to reassemble my exhaust after I remove it to drop the tank. If your are thinking about the other way by cutting the hatch to access the pump from the top then the answer is no I do not want to cut up my hatch. Anyway I am hoping it does turn out to be something simple like the regulator or a vacuum line, but only time and results will tell.

[cam98aro]

Re: Weird starting issues?

First of all, I just want to clarify that I have known my mechanic my whole life. He has been in the business a loooooong time and knows what he is talking about. Second, I said that there was NO fuel in the vacuum line. Third, my mechanic said that he would have to run some test to know what the problem is for sure. He said that it could possibly be the regulator, but it is highly unlikely due to the fact that it is rare that he comes across a bad one. He is simply helping me make sure that we know exactly what is causing the problem before I go throwing money into buying parts and such. So know definitive answer on the cause as of yet. I am going out of town for the week and he is working on it while I am gone. I will let you guys know what he finds out. If it is the pump then I am going to go ahead and let him change it because I don't have the time nor the welding tools to reassemble my exhaust after I remove it to drop the tank. If your are thinking about the other way by cutting the hatch to access the pump from the top then the answer is no I do not want to cut up my hatch. Anyway I am hoping it does turn out to be something simple like the regulator or a vacuum line, but only time and results will tell.

the regulator going bad seems to be a fairly common problem on 4th gens, the fuel pump going bad is even more common, but i have NEVER seen someones fuel pump go bad by being hard to start when the engine was warm.

almost 99% of the time they just die, and thats it.

if the sock was clogged it would be hard starting all of the time, not just sometimes.

your problem really sounds like a bad crank position sensor, the CPS in my friends jeep is bad,and his jeep wont start on the first time, but starts every time on the second try.

when the engine is warm and everything is good it will sometimes start right up, but usually it doesnt.

[88gtman]

Re: Weird starting issues?

Well my mechanic has confirmed from his tests that the fuel pump was the problem. I will let you know more when I pick it up. I had the cps replaced on my jeep and it was running crazy until one day it just died. Will see when I pick it up if the problem is solved.