95 Jimmpy 4.3 Vortec fuel pressure question

[wb8yjf]

Hi all, I'm new to this forum and have a question about my '95 Jimmy SLE 4X4 4.3 Vortec. This all started about 7 weeks ago when the pump died (after filling up of course!). I have changed the following and am STILL having problems:

 

1. fuel pump(Delco), strainer/sending unit (twisted lines) & pulsator

2. fuel filter

3. fuel line (supply) which had a leak in it (rust) - I had this replaced by a mechanic since I ain't good at bending & routing tubing

4. regulator (on orig CPI)

5. nut kit (had a crack and a rubbed hole in it from injector #3)

6. entire CPI/spyder assy (#3 injector has a rub mark in it & looked questionable)

 

After all of this, I am STILL having starting issues. I hooked a fuel prssure guage to the schrader valve on the nut kit line & sometimes when I turn the ignition on (not starting), the pressure will jump up to 55-58 PSI after a few seconds, I hear a relay click and the pressure drops to zero (WTF?) I can find absolutly NO leaks - no smell of leaking gas, etc. If I crank it, sometimes it will fire and the pressure stays at about 55-58 PSI. This is driving me nuts! Any suggestions?

 

Thanks in advance!

Jon

[neex]

Did you solve your problem? Was is a check valve or pulsator gone bad? I replaced the regulator on my CPI unit also only to find that it failed right away.

 

How did you make out?

Thanks.

Andrew.

[00jimmysle]

Having similar problems with my 2000 Jimmy SLT. Have you considered using a Fuel Pressure Guage on the Fuel Intake? Place the fuel pressure guage so you can read it thru the opening of the hood. Make sure all pressure is out of the guage. Put the key in. Listen, check guage. Turn key to the on position and listen for fuel pump, check guage pressure. Wait and make sure guage pressure is AT LEAST 50 psi (Ive heard the Vortex needs 60psi), continue to SLOWLY turn key further WHILE WATCHING FUEL PRESSURE GUAGE. Contine to watch and listen until the starter kicks in. There should be no significant drop in pressure (below 50psi).

[macluvzdavols]

Hi all, I'm new to this forum and have a question about my '95 Jimmy SLE 4X4 4.3 Vortec. This all started about 7 weeks ago when the pump died (after filling up of course!). I have changed the following and am STILL having problems:

 

1. fuel pump(Delco), strainer/sending unit (twisted lines) & pulsator

2. fuel filter

3. fuel line (supply) which had a leak in it (rust) - I had this replaced by a mechanic since I ain't good at bending & routing tubing

4. regulator (on orig CPI)

5. nut kit (had a crack and a rubbed hole in it from injector #3)

6. entire CPI/spyder assy (#3 injector has a rub mark in it & looked questionable)

 

After all of this, I am STILL having starting issues. I hooked a fuel prssure guage to the schrader valve on the nut kit line & sometimes when I turn the ignition on (not starting), the pressure will jump up to 55-58 PSI after a few seconds, I hear a relay click and the pressure drops to zero (WTF?) I can find absolutly NO leaks - no smell of leaking gas, etc. If I crank it, sometimes it will fire and the pressure stays at about 55-58 PSI. This is driving me nuts! Any suggestions?

 

Thanks in advance!

Jon

 

 

try this link ... it should help ... they had the same issue

http://www.howstuffinmycarworks.com/Fuel_p..._regulator.html