About 2500 miles ago, with my H/C/I setup install, I installed a new FRPP 190lph pump, Kirban AFPR, FRPP 24lb injectors, and a permatently fuel rail mounted Autometer fuel pressure gauge. I set the AFPR to 39, vac off and engine off (via fuel pump test connection in the DTC connector). Everything was fine.
Then, since my injectors are a bit too small, I upped the fuel pressure to 43-44ish, vac and engine off. I also changed the Tweecer slopes to match. Not long after, and perhaps coincendently, I noticed the fuel pressure as shown on the gauge, to be constantly fluxuating, bouncing up and down several times a second like 2-4 PSI. I does this all the time, and if I remove the vac from the AFPR and plug the intake vac hole exposed while the engine is running, still bounces, but around 43 rather than the 37ish while vac is connected.
Driveability has also gone south. Seems a bit sluggish at part throttle, idle surging until it dies, A/F ratio at forced OL at idle as reported by WB is rich (13.0-13.5 ish where before it was 14.5-15.5ish). Closed loop criuse seems 'choppy', like the EEC is having a hard time keeping the A/F steady. It can get it mainly at 14.7, but will drift up and down more than it should/did. The car doesn't seem as smooth as it should/did.
If I don't have the engine running and jumper the FP test connection to run the FP continously, the FP gauge reads steady. Engine running, gauge fluttering.
Could this be a bad AFPR? No fuel smell. No apparant fuel leak into vac line. Holds FP for a while (30-90 ??? minutes) like it did before.
Could this be a bad gauge? Would vibration kill it?
Could this be a bad pump?
Could this be ???????
KOEO, no codes.
KOER, no codes.
KOER cylinder balance, no problems (code 9).
O2 switching seems fine (as logged by Tweecer).
No apparant vac leaks, all new vac lines also 2500 miles ago.
No EGR.
No smog.
Thanks,
Rick
Then, since my injectors are a bit too small, I upped the fuel pressure to 43-44ish, vac and engine off. I also changed the Tweecer slopes to match. Not long after, and perhaps coincendently, I noticed the fuel pressure as shown on the gauge, to be constantly fluxuating, bouncing up and down several times a second like 2-4 PSI. I does this all the time, and if I remove the vac from the AFPR and plug the intake vac hole exposed while the engine is running, still bounces, but around 43 rather than the 37ish while vac is connected.
Driveability has also gone south. Seems a bit sluggish at part throttle, idle surging until it dies, A/F ratio at forced OL at idle as reported by WB is rich (13.0-13.5 ish where before it was 14.5-15.5ish). Closed loop criuse seems 'choppy', like the EEC is having a hard time keeping the A/F steady. It can get it mainly at 14.7, but will drift up and down more than it should/did. The car doesn't seem as smooth as it should/did.
If I don't have the engine running and jumper the FP test connection to run the FP continously, the FP gauge reads steady. Engine running, gauge fluttering.
Could this be a bad AFPR? No fuel smell. No apparant fuel leak into vac line. Holds FP for a while (30-90 ??? minutes) like it did before.
Could this be a bad gauge? Would vibration kill it?
Could this be a bad pump?
Could this be ???????
KOEO, no codes.
KOER, no codes.
KOER cylinder balance, no problems (code 9).
O2 switching seems fine (as logged by Tweecer).
No apparant vac leaks, all new vac lines also 2500 miles ago.
No EGR.
No smog.
Thanks,
Rick
Your conditions were sorta different, so I am unsure that it is the gauge, and am tired of throwing money at this car! I don't have a "no-cost" test swap I can do.
