Trouble starting blazer 2000
#1
Trouble starting blazer 2000
Hello, I am having issues turning the car on. It takes like 8 seconds of cranking for the car to start. If I shut it off and try to start it jut seconds later it will start right up. So I went under the hood and did a fuel pressure test and got like 62psi by turning the key, then I get high 50's so I think those numbers are pretty good. The problems is that right after I turn the car off the pressure drop drastically to like 0psi and the same thing happens if I just turn the key without cranking and then just letting the fuel pump shut off. So my question is, is it the fuel pressure regulator, the fuel pump, or the fuel injectors? i am planing to take off the plenum this weekend to see if there is any clean spots inside. Any help would be appreciated since I really don't want to take all those parts off to find out that it is the pump or something else. Thanks!!!
#2
62psi is good, below 60psi is not. Does the pressure drop after the pump shuts off?
Check out the Tech Article (DIY) section for the 96+ Fuel System Diagnosis thread.
Check out the Tech Article (DIY) section for the 96+ Fuel System Diagnosis thread.
#3
Yeah it drops like crazy to like 0 psi. So something is loosing a lot of gas. Something that is very weird is that if I actually let the fuel pump run twice before turning the key to crank the engine the car starts right up. But if I just turn the key to crank the car takes like 8 seconds. Which means it is not holding the pressure right after I turn the car off and the fuel pressure test proved this. So I am confused whether it is the fuel pump's check valve or the problem is at the other side inside the plenum. I don't want to be taking stuff apart if I am not somewhat sure.
#4
Classic FPR failure. The pump needs to build pressure before it will start properly. Sounds like you need to get under the plenum and replace the FPR.
#5
Thanks a lot, that is exactly what I am going to do. Now my next question is, I just seen in autozone that they sell like a diaphragm kit for the FPR, Should I just get that or should I buy the whole thing brand new? I am kind of short on money.
Also, while I am inside the plenum should I get a kit to rebuild the fuel injectors like the one seen on this forum http://forums.minnesotamud.com/showt...?t=3538&page=2
since they are pretty likely to leak in the future since I got 106,000 miles? I have attached a picture of the fuel injector kit. Is this kit just for missing parts or is it to actually fix leaking injectors?And what should I use to clean the injectors once I take them off?Thanks for the help!!!
Also, while I am inside the plenum should I get a kit to rebuild the fuel injectors like the one seen on this forum http://forums.minnesotamud.com/showt...?t=3538&page=2
since they are pretty likely to leak in the future since I got 106,000 miles? I have attached a picture of the fuel injector kit. Is this kit just for missing parts or is it to actually fix leaking injectors?And what should I use to clean the injectors once I take them off?Thanks for the help!!!
Last edited by blacer2000; 07-30-2009 at 08:04 AM.
#6
So if I put the fuel lines back in place would I see gas leaking from the FPR after the fuel pump builds pressure? Or can they still be bad and not leak?Thanks for the help.
#7
Today I am going to see if when the pump builds pressure on of the injectors or the FPR is leaking!!!
#8
The newer FPR's do not fail into the plenum like the older ones do. They typically will just not work properly, bypassing too much fuel back to the tank.
You may want to test the fuel pressure at the fuel filter to make sure that the check valve in the pump is working properly.
You may want to test the fuel pressure at the fuel filter to make sure that the check valve in the pump is working properly.
#9
So i got a new FPR and I think is a little better , but the pressure still drops to almost 0psi in like 5min. I could not see any leaks or smell anything. So what does that leave me with??A bad check valve on the fuel pump??? One more thing, does the return line to he gas tank have a check valve or is it just the fuel pump???Thanks for any replies i really appreciate it!!!
#10
Only the pressure line has a check valve. And yeah, that pretty much leaves the check valve in the pump.