1995 Tracker bog issue

[fixkick]

the vacuum when you start the hot engine (800 rpm hot) does 19"inches of vacuum
and the fuel pressure MUST FALL 6 PSI.
yours DOES NOT do that at all. yours did nothing at that keyon, to start transition.

[fixkick]

The car is old, i'd never blame all failures on the hurricane water flood. no me, lets do the tests, , prove what is wrong, all things.
Never seen any 1995 car ever with just 1 problem, not me, would be 10 issues, in most cases.
your car is not bogging, but is misfiring and is due to way too much fuel at the injectors.
symptoms will be. (like this) with that FPR.
black tipped spark plugs.
the CAT is still working will want to glow red hot and melt inside, (choking engine to death) (1996 car flashes the CEL, for this CAT killing error)
the car will suck fuel like crazy not 25mpg but 15mpg, is possible. if car can even go fast enough to test MPG.
the engine power will be low (some call that bogging, but is not it's gross misfiring) a 1996 car would through P0300 endlessly. for misfire. all and random.
sure bogging can be lean bog and way too rich bog) but best is to just diagnose the rich burn.

The FPR on this old car is known to fail this old, vast FPR are now dead. 1995 is way too old for any FPR. (IMO)
fact 2 is the FPR is not tested by the ECU like all modern cars do, MPI ,for sure with non loop fuel systems. so THIS ECU is blind to this classic failure.
make sure the fuel line (return) is not pinched /restricted or routed wrong. like the last poster here did, he had the FPR hosed up to the EVAP lines some odd way. IDK but is true.
the vacuum ports most also work from plenum to FPR nipple and some nipples on the plenum do pack up with crap.(PCV nasty gunk)

the FPR is like $60 at rockauto watch out for rockautos penchant for not asking what engine you have!, in usa its 2, engines and outside USA more. (most stores do this too, not asking what engine it is... and really is a pain in the backside that)
but this is MPI 16v, do not buy the one that is TBI 8v.

this FPR has dog leg shaped, return line, unlike the 8v with short straight nipple.
http://fixkick.com/sensors/thermostat/96...mine1w.jpg
the best way to get the right FPR, new, is make sure the same P/N works on 96-98 too. 92 to 98 16v.

SMP makes nice parts.
https://www.rockauto.com/en/catalog/geo,...lator,6124

[fixkick]

why does 30 contradict post 19 on fuel pressure.
im so confused. now.

but in both posts fuel pressure is totally WRONG.
you need to make sure the FPR return line is not blocked, or restricted, pinched or routed to the wrong hose/pipes)
fuel pressure is wrong! for 100% sure.
at least now we know why, only true and actual cause is not known.
1: fpr bad.
2: return line wrong. (all ways from sunday wrong, take your pick) end to end from FPR to the tank, can be wrong.
3: someone put in pump rated 2x the GPH rating, ( a very non stock pump! way too powerful pump, have examples I do...)

here is the left side of tank
see the return line?
(the routing can be wrong on both ends, inspections are simple, just look , Id follow every inch of that line, first, for 2 things ,damage or wrong lines used.(routing)

[fixkick]

if the last guy that pulled that tank did not label all hoses (A to A , B to B) etc.
then he transposes, evap for return.
bam FPR goes nuts.
never pull down any car, and not label hoses. or super bad things can happen. (small hoses, for fuel ,evap or vacuum ,need labels. )

[randyz71]

yes at the MFI port, I ordered the 2267 adapter with Harbor Freight fuel gauge .
I have taken fuel cap off, also ran it with 02 sensor out of manifold to see if that helped in case of clogged cat but nothing changed. probably not the best thing to do but tried to start car with only 1 spark plug wire on at a time for each cylinder, and it ran on that 1 cylinder (all 4 but 1 at time ran) This car was meticulously taken care off and the maintainence done regular. we have had it for a couple of years and had driven it about 4000 miles before the flood.
I will check return lines, and run fuel test again.

[fixkick]

what matters is facts and tests, age is old. but like all old cars, even service can not keep up with age, ok?
like hoses failing is classic, this old. and not changed.
the FPR is failing , that is 1 fact, why we don't know yet. (what if car had a cloned FPR from china put in and it hates USA 10% alcohol)? IDK , that is why I test it,
its simple and classic failure for cars this old. super common. now. the FPR does not have vent hole so is water proof, outside to inside. (see why testing works not blaming all on mr, hurricane?.)
in shop the bucket tests are many but this is only one test, above. (GPH test is another)
the fact is , that time or money is the only issue. (and down time, too, shop labor time and shipping time if local stores have no parts)

testing time and labor
or buy new one cross fingers return lines not bad. you call for sure.
THE FPR IS DEAD or the return line is bad.
or the vacuum nipple is dead. seen one car that had the vacuum nipples packed in EGR GUNK (EGR +PVC black cloud of crap does that in the Plenum)
pull hose, use un bent paper clip or smokers pipe cleaner to clean the nipples, or test the plenum nipple by pulling the hose off vacuum and feel it suck hard.
if vacuum is good, next is return line blocked in all ways stated above.
if that passes the FPR is dead, a very very very common failure now, and service does not cure this, (i mean tuneups. etc)
(service is, (service points only do) fluids,filters, belts, spark parts,PCV valve,and 02 sensor at 100k miles. and nothing else, (unlike air aircraft)
And EGR valve cleaned at 60k for sure.(just engine is topic.)

yes at the MFI port, I ordered the 2267 adapter with Harbor Freight fuel gauge .
I have taken fuel cap off, also ran it with 02 sensor out of manifold to see if that helped in case of clogged cat but nothing changed. probably not the best thing to do but tried to start car with only 1 spark plug wire on at a time for each cylinder, and it ran on that 1 cylinder (all 4 but 1 at time ran) This car was meticulously taken care off and the maintainence done regular. we have had it for a couple of years and had driven it about 4000 miles before the flood.
I will check return lines, and run fuel test again.

[fixkick]

good at the rail pressure, is best, good.
fuel filter clean (yours is ok) and air filters. (if the air filter clogs, the FPR lowers fuel pressure to compensate {higher vacuum}, and yours fails this.)

[randyz71]

I understand exactly what you saying, things fail and wearout. Ran fuel pressure test again, this time 42psi just sitting but drops fast to 35, it is a steady 35 at idle and if accelerate slowly stays 34 to 36 psi, if accelerate fast it bogs and jumps to 40psi let off fast it drops to 30 for split second then back to 35, did not pull vacumm again. I ordered new FPR be here in a few days. The one thing I really liked about this track is low miles, 118 something thousand and all parts are OEM. I was running it without air filter when the issue started ( forgot to get one after dry out) but I did put one in so it's new. Hopefully new FPR will fix it. I got from advance Auto so has a warranty it fails again.

[fixkick]

your posts are not clear, is engine hot or cold, best is HOT, so we can correlate data. 800 RPM hot idle. you have tachometer 4wd, so when hot is the RPM at 800rpm? 0.8 (1k per tick on dial) 1 = 1000 rpm. so 0.8 is normal is it?
what is your altitude, (sealevel or on mountain, would love to know this) im at 500ft right now where are you"? how high.?
this is physics and the FPR is and altitude device too. so matters.
as altitude rises fuel pressures drops. if not the engine floods with fuel. as yours does.

not one number below is correct. the start high and then all are high but I see vacuum works but the numbers are all high.
my guess is the FPR valve parts leak, the seat in the valve is worn out (shock?) and leaks. causing OFF SET high pressure.
or the return line is partially blocked or as the other poster here had the hose crossed.
but you will find out soon, hope its and easy fix. good luck!

I understand exactly what you saying, things fail and wearout.

Ran fuel pressure test again, this time 42psi just sitting (hot engine or cold, keyon not started?) this???????? this crazy too high, what test is this?

but drops fast to 35, it is a steady 35 at idle and if accelerate slowly stays 34 to 36 psi, if accelerate fast it bogs and jumps to 40psi let off fast it drops to 30 for split second then back to 35, did not pull vacumm again. I ordered new FPR be here in a few days. The one thing I really liked about this track is low miles, 118 something thousand and all parts are OEM. I was running it without air filter when the issue started ( forgot to get one after dry out) but I did put one in so it's new. Hopefully new FPR will fix it. I got from advance Auto so has a warranty it fails again.

[randyz71]

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!