02-06-2019, 11:07 PM
post 61 only short answer...
here is what you said.
"key on not started 40 psi fuel pressure. WOT while bogging 40 to 41 psi " (this can be good, and is, but why not post all fuel tests at one go, here?)
all data points told at once. like this.
vacuum readings and fuel pressure readings, both while
doing these test,
keyon nostart (40psi pressure at 0 inches vacuum)
key on idling (math 40-6 = 34PSI ,20 inches vacuum) if stuck at 40 the engine floods and misfires.
and the wot instant reading. (before it reduces fuel pressure ) the vacuum will drop to near zero at first, and FPR raises pressure to near 40psi. then as engine catches up (fuel press.drop later)
if you gun the throttle and see fuel pressure change, rise then fall, then at at say 4000 rpm (approx) drop the hammer, (throttle) the vacuum goes super high, and fuel pressure goes
supper low. as the engine spins down the vacuum is huge, with engine acting as a huge powerful vacuum pump, 26 inches Hg. is possible on strong engine. and fuel pressure is low 20's then
and lastly as engine spools down. the fuel pressure returns to 34PSI hot idle and 20 inches vacuum again.
that is how I test all FPR on car, 2 gauges.
it is a key test. to fuel injection, and if wrong the ECU may not be able to compensate for greatly wrong fuel pressure.
----------------------------------------------the list of things checked-------------------------------------------------------
If I am not mistaken.
engine is good. compression good. 185psi. and we know vacuum is ok, not odd .
spark unknown? state.
all 4 spark plugs run black tips.(a huge and important clue) and why I'm all over fuel pressure.(sorry but FPR's love to fail this old)
MAF can be bad, it is very hard to test on ANY weak engine, (cant suck enough air is why. )
the chicken and the egg, conundrum. (a weak maf nets you a weak engine and a weak engine nets you weak maf readings.) see?
most maf failures fail to weak not rich, fuel. so in most cases the maf never causes 4 black spark plugs.
a good maf shows added air flows as soon as you touch the throttle, and the ECU adds fuel matching that air flow. (if not engine bogs, lacks power)
the other cause is bad spark, I have scope to test spark and you dont so... tests are harder.
if you hear misfire, an spark ignition test light may show it fail, (connected to all spark wires 1 by one see if you can see it misfire in the LIGHT flashes ) a crude test but can work for you.
The spark can fail for many reasons.
bad spark plugs (they are not)
bad spark wires, (or spark timing set way wrong)
bad coil
if you drive the car and scan it after many driving cycles the ECU will show P0300, means misfire on all 4 cylinder random. one trip will not set this error, takes driving 2 times.
one guy found even the distributor side cable bad ,damaged, or rusted.
bad cap.
bad rotor or those damn china rotors clone crap (C4) that fit on 3 ways, and one of the 3 is correct, and other way causes horrible spark intensity, and 3rd way a dead engine
buy a bosch rotor, not "som ting wong" brands. use top names in parts, and win.
a bad distributor is possible, the coil is buried inside. so....there is that.
please add to list of changed parts, above.
cheers and good day to you !!!!
here is what you said.
"key on not started 40 psi fuel pressure. WOT while bogging 40 to 41 psi " (this can be good, and is, but why not post all fuel tests at one go, here?)
all data points told at once. like this.
vacuum readings and fuel pressure readings, both while
doing these test,
keyon nostart (40psi pressure at 0 inches vacuum)
key on idling (math 40-6 = 34PSI ,20 inches vacuum) if stuck at 40 the engine floods and misfires.
and the wot instant reading. (before it reduces fuel pressure ) the vacuum will drop to near zero at first, and FPR raises pressure to near 40psi. then as engine catches up (fuel press.drop later)
if you gun the throttle and see fuel pressure change, rise then fall, then at at say 4000 rpm (approx) drop the hammer, (throttle) the vacuum goes super high, and fuel pressure goes
supper low. as the engine spins down the vacuum is huge, with engine acting as a huge powerful vacuum pump, 26 inches Hg. is possible on strong engine. and fuel pressure is low 20's then
and lastly as engine spools down. the fuel pressure returns to 34PSI hot idle and 20 inches vacuum again.
that is how I test all FPR on car, 2 gauges.
it is a key test. to fuel injection, and if wrong the ECU may not be able to compensate for greatly wrong fuel pressure.
----------------------------------------------the list of things checked-------------------------------------------------------
If I am not mistaken.
engine is good. compression good. 185psi. and we know vacuum is ok, not odd .
spark unknown? state.
all 4 spark plugs run black tips.(a huge and important clue) and why I'm all over fuel pressure.(sorry but FPR's love to fail this old)
MAF can be bad, it is very hard to test on ANY weak engine, (cant suck enough air is why. )
the chicken and the egg, conundrum. (a weak maf nets you a weak engine and a weak engine nets you weak maf readings.) see?
most maf failures fail to weak not rich, fuel. so in most cases the maf never causes 4 black spark plugs.
a good maf shows added air flows as soon as you touch the throttle, and the ECU adds fuel matching that air flow. (if not engine bogs, lacks power)
the other cause is bad spark, I have scope to test spark and you dont so... tests are harder.
if you hear misfire, an spark ignition test light may show it fail, (connected to all spark wires 1 by one see if you can see it misfire in the LIGHT flashes ) a crude test but can work for you.
The spark can fail for many reasons.
bad spark plugs (they are not)
bad spark wires, (or spark timing set way wrong)
bad coil
if you drive the car and scan it after many driving cycles the ECU will show P0300, means misfire on all 4 cylinder random. one trip will not set this error, takes driving 2 times.
one guy found even the distributor side cable bad ,damaged, or rusted.
bad cap.
bad rotor or those damn china rotors clone crap (C4) that fit on 3 ways, and one of the 3 is correct, and other way causes horrible spark intensity, and 3rd way a dead engine
buy a bosch rotor, not "som ting wong" brands. use top names in parts, and win.
a bad distributor is possible, the coil is buried inside. so....there is that.
please add to list of changed parts, above.
cheers and good day to you !!!!
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