a968

For a few months I had been having problems with cold start on my 1990 IROC Z 5.7 stock engine. When cold starting it would take about seven tries before I believe gas filled the lines and it would start. After driving around and operating temp, I had no problems with it starting until it sat for an hour when it again would take some time to start.

From reading some post, I decided to go ahead and purchase some refurbished fuel injectors, replace the pressure regulator to try and fix cold start problem. After the new install (two days) the car would not not start until starting fluid was sprayed into throttle body and then it died.

A check of the injector wires with a noid light showed that they had good pulse, the fuel pressure test on the line showed no pressure.

A buddy who at one time had an IROC came over and checked the fuel pump relay, fuses under dash (next to battery), spark with noid light again and told me it could be the fuel pump not working properly even though I could hear it prime every time. He checked that the tank had gas and said if the fuel pump was working properly gas would spray out of the line where it screwed into the fuel rail. He pulled the fuel lines from the fuel rail and after I tried starting the car, only a small spray of gas came out of the line? Tried turning the engine several times again and still no gas?

Before dropping the tank (PIA)job, is there any way to test the pump or other checks I could try to solve the problem?

Thanks

fireburdluvr85

Hook a gauge to the Schrader valve and actually check the pressure. Should be around 43 psi

Caveman305

iTrader: (8)

he said fuel pressure test resulted in no pressure


to me that means the hose that connects the pump to the line is damaged, mine was split resulting in no pressure even though the pump worked fine

i replaced the entire sending unit which included a new pump, couldn't beat it for $115 and for the first time in 7 years my fuel gauge reads the proper level

yes you will need to drop the tank, no its not that bad of a job

86T/A_Ram_Air

Yeah if your gonna go through the trouble of dropping the tank you might as well change everything in the tank

fireburdluvr85

Made no mention of actual pressure but after re reading I will agree. The line in between probably is deteriorated.

rgarcia63

there's also a fuel filter on the supply line to the engine. I assume you've already checked, or replaced it.

a968

Thanks for the information. I will work on dropping the tank probably this weekend. I also changed the fuel filter and no luck. Will let you know the results. Again thank you!!!

a968

Update: Car running!!!Dropped the tank and replaced fuel pump. Thanks for all the help!

Caveman305

iTrader: (8)

Good job and beautiful car!