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sorry i forgot your location.
yes, on this car the fuel pressure must be in spec. yours is acting real odd.
good, no crossed lines. must be gauge lies or FPR bad.
the return line can not be restricted, in most cases this does not happen. (not parked for year with bad fuel)
800 rpm spec is +-50rpm so 750 is dead on.
the trick with the FPR is that it keeps differential pressure across the injector constant. (vacuum regulation does that)
ok, good luck , im off on vacation now.... but will read these.
cheers.
(01-01-2019, 09:21 AM)randyz71 Wrote: I am at sea level, 40 miles sand of gulf of Mexico. It is same cold start or after reaching operating temp. No way in my opinion lines can be crossed because they are sane as when I bought it and has ran like a top for several hundred miles. Rpms after warm is closer to 750, I really appreciate your experience and insight, I know gm vehicles pretty well, wanted to be a mechanic in past life and worked in garages in high school, a couple ASE classes, but this thing kicking my butt. Again your experience and help is invaluable! Thank you!
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Got the new FPR on last night, 40 psi key on 40 psi idle, 38 psi during acceleration but still bogs and runs worse than it did before.
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remembering what I said as any mech would or car restoring person or shop would say
no 1995 car has 1 problem not one, unless seen in a autoshow (contest ing for perfetion etc.) or museum or the like.
none.
that is ASSUMED always, and is expected.
16v mpi , new fpr for G16B mpi, and no other cars or engine or years.
quote='randyz71' pid='10943' dateline='1547039973']
Got the new FPR on last night, 40 psi key on 40 psi idle, 38 psi during acceleration but still bogs and runs worse than it did before.
[/quote]
so 40 and 40 are wrong and so is 38
with good FPR now we see the truth, for the first time.
why did you skip the shunt test.
why not do vacuum reading as the same to, so prove see, vacuum is right ,even to the point of using 50cent Tee fitting on the FPR vacuum line!
if vacuum is good. IDK it is.
then the pump is failing.
the fuel pressure is wrong, and most not be like that at all.
it looks like one of 3 things wrong, (lack of testing data , no vacuum readings same time)
1:new FPR is bad, what brand was it,? I'd say not bad but any skilled tech never never assumes, he tests and proves what is wrong.
2: vacuum not reaching FPR, common on all G16B ,and the vacuum nipple is packed full of EGR CARP plus PCV crap, call it double gunked and crapped out.
3: weak pump if shunt fails, 55psi is par. not 40. never 40 ever.
one other tests not done is:for sure shunt test next then.)
at idle, 800 rpm
we remove the nipple fast,. and connect my hand vacuum tool,all shops have this tool or fail.
we run the FPR at all vacuum points for sure 3.
we run 0 hg , engine will want to run rich and misfire. fuel pressure is now max. spec.
we run 20 hg( par for idle)
we run 26 inches HG, to see if FPR runs right on the whole line of my graph posted here. fuel pressure is now MIN spec.
if that passes but not on the real vacuum hose that means the hose is or clogged or cracked , 100% sure.
ive seen my 91 vac hose turn to black slime, yea, turning back to crude oil I guess, nasty nasty sizuki hoses do that.
more later,,,,,
but this is it. mostly
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the history of 1995 cars, all,
1:owners do not fix things that break .
2:most cars this old shop repairs can be 2 times value of the car. most this old are like $500 but this car here, a 4wd, is worth more just for those words 4wd
and or high ground clearance or for snow.(ice)
3: the owner ignores , CEL lamp glowing, (or dead) and all service points (called tuneup. s to us old folks)
4: the failures add up, and some compound.
5:many failures hide other failures. (classic case, wiith a car engine dead, the owner fixed engine, now 3speed auto is dead. oops
lots and lots of things can be bad and for sure bad wiring on this car, horrible grounds.
in your case we have duel fuel pressure failure, we can find it easy with testing.
with a bad pump you can not test the FPR
with a bad FPR you can not test the pump easy,but there is a long set of tests with buckets and flow gauges, yes we can.
the first test skipped was the shunt test (to A pump man, its call the HEAD TEST ON THIS CAR WE PINCH THE RETURN LINE FOR SAY 3 SECONDS, NOT MINUTES
AS THIS IS HARD ON PUMPS. SHUNTED.
ON HUGE V8 THE SHUNT CAN HIT 100PSI. OR MORE.
THIS CAR IS 55 TO 60PSI, MY pump page even shows all pump spec.s flow and all.(got it from Gm/Delco)
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01-10-2019, 02:21 AM
(This post was last modified: 01-10-2019, 02:24 AM by fixkick.)
PSI GUAGE ON RAIL IRST
when the engine starts
we remove the vacuum line, and golf TEE the sucking end of the vac line, if it dont stuck we fix this now.
ok then engine runs still,HOpe)
the vacuum is zero. at FPR IS ZERO VACUUM
THE FPR THEN THINKS TV IS WOT, WIDE OPEN THROTTLE SO FUEL PRESSURE GOES TO MAX SPEC. MY CAR 36psi (2 CARS)
http://www.fixkick.com/INJECTORS/PUMP/re...-mpi-g.jpg
I CONNECT MY HAND VACUUM HAND PUMP TOOL TO FPR NIPPLE DIRECT (NOT TEE'D) $28 AT HARBOR FRIGHT(PUN)
I PUMP TO 20 INCH HG. fuel is at 30psi, note the 6 PSI DROP THIS IS NOT OPTIONAL, 6PSI DROP
I PUMP THE HAND TOOL TO 26"HG, FUEL IS AT 21PSI NOW IT 9PSI DROP,.
THAT IS HOW IT WORKS IN TEXAS HERE AND WHERE YOU ARE, ON THE SOUTH COAST (I ALMOST MOVED TO GALVESTON)
WITH THE FPR HOOKED UP NORMALLY THE SHUNT TEST HITS 55PSI,
YOUR 40 PSI IS TOO MUCH.
FOR SURE
WHY IS EASY DOING TESTS, LETS DO THEM
YOU CAR FLOODING, MEANS GROSS RICH FUELING THE ecu can not correct
the engine will misfire baddly, you can call that bog ,but it is misfiring and the black tipped spark tips tells you that all 4 are grossly misfiring
due to grossly too high fuel pressure and no real regulation at all, and gross over injections, all 4 injectors,
id be all over that vacuum hose and engine plenum nipple like tick on coon dogs butt.
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your fuel pressure regulation fails,fails hard.
so hard it looks like someone put screw,stuffed deep in the vacuum line, seen that 2 times (folks trying to defeat smog)
i'm shoot'in from hip here.
i do the tests, and let the facts tell me what's UP.
guessing can work 1/2 the time, or not at all.
and assuming is the pit of hell.
the mother of failure is ASSUME.
endless list of things that can fail.
bad new parts
bad wiring or hoses.
hose routed wrong. oops. tell my the FPR is not routed to the DANG evap or EGR vacuum system, I can see your engine.....
bad pump
bad return line clogged or pinches at the metal line on right inside frame rail ever do underbody inspections? for road hazard damage, or loose bolts on things that are man killers or see brake fluid leaks now.? would you test drive car like that, not,me.
my 91, day 1 , hour1, the left front lower A arm was about to fall off car,,,, yeah 1boot gone 1 hanging by 2treads. oops. man killer car.
i inspect first. for damage and leaks the whole car
then look for bolts loose on key things,
and for all hose or lines damaged and for sure vacuum lines connected dead Wrong.
I Tighten all ground lugs, seen on my ground distribution failure pages. or clean them if rusty.
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01-10-2019, 11:18 AM
(This post was last modified: 01-10-2019, 11:18 AM by randyz71.)
ok im getting home about dark working with flashlight, will do more this weekend, I put old FPR back on, it is around 35 to 38 psi running 40 or so before startup. vacuum at the hose that connect to fpr is about 45 to 48, did shunt test it jumped into the 50 plus range and fuel sprayed from leaking fittings on harbor freight gauge so didnt get good reading. will try this weekend some time.
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vacuum at the hose that connect to fpr is about 45 to 48,???????????? i am not sure what that means.(the word pulled skipped? ,im guessing)
48 is wrong for vac line pull, dead wrong. why too high.
WHO SOLD NEW FPR, (ebay) and what what the makers name,? of FPR on the box, or was was it a USED FPR
did you check vacuum first, the FPR is a VACUUM device. and if vacuum is wrong, FPR can never work;
shunts ok.
that means. pump is ok.
leaving what)?
1:bad vacuum
2: bad FPR
3: return line clogged or crushed
4: wrong return line used, mixed up with evap lines ( hard to do but someone did just did last week on this forum)
5: horrible and nasty bad fuel causes FPR to clog up fast. but only if fuel flter was bypassed,, im blind on this end i can not inspect and car here
where did the FPR come from, the 2nd FPR, I cant see you open the box, nor the name on the box nor p/n on it.
delco, carter,SMP
did you buy a quality FPR FROM A TOP MAKER, SEEN HERE.
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THIS CAR HAS EFI, AND WORKS TOTALLY UNLIKE SOME OLD GM CARB CAR.
and fuel pressure is first, and if wrong, (out of spec as yours are) it can not inject correctly
the old GM(relic) had this funny in the TBI top FPR, that run crazy low 10psi pressures. and they went bad (high) the flooded endlessly.
same as this G16v will.
here is the relic GM now video, see GM at this crazy TBI system that is best forgotten but is cool to see injectors work, no>?
https://www.youtube.com/watch?feature=pl...eHgh8#t=30
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FPR is new from advance auto came in a carquest box part#23011. the vehicle was missing badly because of carbon fouled plugs at that tine the vacuum was about 30, after cleaning plugs vacuum increased to 45 or so vacuum but rpms were in the 1200 range at that time (cold engine). I took vacuum reading at the hose that connects to FPR. I pulled vac. hose off FPR left it attached to Plenum and attached gauge in place of FPR.
when I disconnect return line from FPR gas comes out of return line, is this normal?
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