Ironcheflove Posted August 3, 2014 Share Posted August 3, 2014 I've got a 1997 L 2.2 Auto and I've finally chased down an occasional hard start issue to a fuel issue after testing the pressure in the system. When I run it with the vac hose on the pressure reg. I get 26-27 PSI and with it off 37-38 PSI. I then close off the return line for a sec and the pressure climbs quickly to 50+ PSI. I then put a hand vac pump on the pressure reg and when I applied vac fuel pressure dropped down to 26-27 PSI and when vac was released it went up to 37-38 PSI. I know spec pressure is 26-32 PSI and according to Haynes with that trouble shooting procedure that it tells me the fuel pressure reg. needs to be replaced but think I should do the pump too since it's reading on the low side of spec? Was going to check pressure after I get the pressure reg from Amazon but don't want to wait on the pump shipping later too. Was thinking Bosch on both parts. Options on it all? Link to comment Share on other sites More sharing options...
mnstrmech Posted August 4, 2014 Share Posted August 4, 2014 Pressure regulator is working perfectly fine. According to Mitchell on Demand, and my professional experience, your fuel pressures are right on the money. The pressure regulator is suppose to increase fuel pressure according to vacuum (engine load). Now i had a hard start issue a while ago and it was the fuel pump not kicking on right away. Keep that pressure tester on and see how fast the pressure builds while cranking.... Link to comment Share on other sites More sharing options...
Ironcheflove Posted August 4, 2014 Author Share Posted August 4, 2014 OK then I don't understand how pinching the return hose close and the fuel pressure spiking up means that the reg is bad. Or is Haynes ******* with me... Link to comment Share on other sites More sharing options...
mnstrmech Posted August 4, 2014 Share Posted August 4, 2014 Pinching the return line gives nowhere for the fuel to go, hence pressure spike. Only time to replace the regulator is if you pull the vacuum hose and have fuel spray out the vacuum port, which does happen.... More so on GM vehicles... very rarely do i see regulators stick internally. I dont know what Haynes says, I've always had access to Mitchell on Demand or Alldata, which is word for word from the factory repair manuals. The couple times i looked in Haynes, it wasnt very accurate. You could try your local library. The libraries in my area carry the factory service manuals. Link to comment Share on other sites More sharing options...
Ironcheflove Posted August 4, 2014 Author Share Posted August 4, 2014 I get the part about the pressure spike but how does that tell me I have a bad pressure reg. is what I don't get. Link to comment Share on other sites More sharing options...
mnstrmech Posted August 4, 2014 Share Posted August 4, 2014 Gotta be bad info from Haynes... Link to comment Share on other sites More sharing options...
Ironcheflove Posted August 7, 2014 Author Share Posted August 7, 2014 Well got the FPR on and tested again, the pump was shot too. Smoothed out my rough idle enough until I can do a grounding mod. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.