Been half-heartedly chasing this issue for awhile, but now I've had it! Gotta get this issue fixed. Broke out the FSM, bought a fuel pressure gauge set, and went to work.
Started with pulling the cold start injector (FSM, pages FI-52-53) I cleaned it up not long ago, but figured I would make sure...
1. Resistance at 3.8 ohms (2-4 ohms spec'd.)
2. Spray pattern even and good.
3. I noticed that when loosening the CSI, there was no pressure being evacuated... Not a good sign, I think.
Moved to FSM pages FI-47-49 (following line by line):
1. FI-48(k) tests at 44psi (37-46 spec'd) (fuel pressure with jumper in place, gauge installed directly on the fuel rail)
2. FI-48(o) tests at 46psi (37-46 spec'd) fuel pressure @ idle
3. FI-49(q) tests at 40 psi (33-37 spec'd)
4. FI-49(r) fuel pressure should remain greater than 21psi for a minumum of 5 minutes.
Here lies my question. Fuel pressure @ idle with vacuum hose disconnected from FPR is high; when the engine is shut off, the pressure immediately drops to ZERO. I have no experience with FI systems, so I'm asking for guidance and knowledge, as my searches through the site have not netted me a definitave firm answer in my mind - does this indicate the FPR and/or the FPD need replacing? FSM says check fuel pump, pressure regulator, and injectors. I figure that some guru here (@jonheld, perhaps? ) would be able to give me some insight based on their experience. Knowing that I have a near-30 year old rig, I would like to (but my wallet would not) rejuvenate the fuel injectors as well, but baby steps...
Thank you in advance for the help.
Started with pulling the cold start injector (FSM, pages FI-52-53) I cleaned it up not long ago, but figured I would make sure...
1. Resistance at 3.8 ohms (2-4 ohms spec'd.)
2. Spray pattern even and good.
3. I noticed that when loosening the CSI, there was no pressure being evacuated... Not a good sign, I think.
Moved to FSM pages FI-47-49 (following line by line):
1. FI-48(k) tests at 44psi (37-46 spec'd) (fuel pressure with jumper in place, gauge installed directly on the fuel rail)
2. FI-48(o) tests at 46psi (37-46 spec'd) fuel pressure @ idle
3. FI-49(q) tests at 40 psi (33-37 spec'd)
4. FI-49(r) fuel pressure should remain greater than 21psi for a minumum of 5 minutes.
Here lies my question. Fuel pressure @ idle with vacuum hose disconnected from FPR is high; when the engine is shut off, the pressure immediately drops to ZERO. I have no experience with FI systems, so I'm asking for guidance and knowledge, as my searches through the site have not netted me a definitave firm answer in my mind - does this indicate the FPR and/or the FPD need replacing? FSM says check fuel pump, pressure regulator, and injectors. I figure that some guru here (@jonheld, perhaps? ) would be able to give me some insight based on their experience. Knowing that I have a near-30 year old rig, I would like to (but my wallet would not) rejuvenate the fuel injectors as well, but baby steps...
Thank you in advance for the help.