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1995 Tracker bog issue
30 inches, is wrong. so is 45inches. 45 inches of Hg mercury column vacuum is impossible on( the Vac gauge is RELAtiVe VACUUM,NOT ABSOLUTE)
Please post PSI fuel pressure , and vacuum in the Plenum in inches of Hg. together.
your injectors are super over injecting so the engine floods, and fouls spark plugs but we know why, the fuel pressure is dead wrong.
and too high.
vacuum is never 30, ever.why do you tell this? is your gague wrong or is the gauge only in KPA (metric)

yes the return line flows full time running engine at speed and any hill on earth.
if the return line is blocked the fuel pressure goes sky high (wrong) .

that carquest fpr should be Ok
Got the new FPR on last night, 40 psi key on 40 psi idle, 40 at idle is dead wrong. 18PSI too high

38 psi during acceleration but still bogs and runs worse than it did before.
all this is wrong,dead wrong.
the reason i can answer is the lack of vacuum at each PSI fuel pressure stated. (use a 50cent vacuum TREE fiittng)
or remove the vacuum hose on the pleanum tank, front brass nipple, going to evap VSV electric valve.
this must suck air if running, if not clean this nipple first.
now with vacuum gauge Inches of Hg,mercury gage (usa use Mercury Hg vacuum) the rest of the world uses BAR, do not post BAR readings or KPA,here.
now with that fitted, to evap nipple
the vacuum readings can be done easy and fuel pressure at the same time.

can you post a photo of your vacuum gauge and PSI fuel gauge.

as you can see there is no 45inches of vacuum possible on earth.
when the engine going fast down hill, and you lift right foot, in lower gears the engine is huge vacauum pump and can hit 26 " or more\
but 45 is not possible.

[Image: 3_10_01_19_11_31_11.jpeg]
i do not have cold engine data (besides temperature and rpm)
I do not have cold engine vacuum data. because the IaC is not know at all. but advancing throttle will drop below 19" or IAC opened sure will. cold.
all tuneup data is hot engine 180f. idle is 800, vacuum is 19" or near.
fuel pressure is known at all vacuum readings hot or cold engine.

what blows me away is this

"at that tine the vacuum was about 30, after cleaning plugs vacuum increased to 45 "

this is impossible.
not sure how to post pics? but after looking at a pic of the gauge you are correct I was reading it wrong, in the dark with flashlight. lol
it is the harbor fright vacuum/ fuel tester. the reading in Hg vac is really 17 to 18 in, I was looking at cm Hg vac. which is 45 cm
please do not use metric readings for sure mixed with PSI ,imperial measurements.
use PSI and inches HG only please.
that inner scale is for (ROTW, rest of the world ,not us Gringo's) I can do Bar no problem but mixing is bad idea here)
please use only PSI fuel, and inches Hg. readings. and we can test FPR easy in USA.
now where I got lost at post 47 (old fpr)
Quote: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(cmHG), 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.
leaking at rail , or leaking at FPR nipple bad.?????
there are 2 gauges here,which one leaks fuel?

and worse new FPR (post 42 is worse far far worSE)
Quote: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.
as you can see vacuum is 100% dead at FPR engine stated, 40 to start 40PSI and idle.
the new FPR seems to have the vacuum hose missing (flashlight , sure... been there,)

what we are also doing wrong is not doing tests on a hot engine, all measurements running are hot engine
for sure 800 rpm idle,its key data point, means (standards) to test the FPR and say good or bad.

the vacuum tool must be INSERTEd in one of 2 places
the EVAP nipple on the front intake plenum face, pull EVAP hose us the nipple on the aluminum huge plenum tank
far far far better, use any inline TEE fitting ,connected to the FPR vacuum hose , extend the hose is best cutting hose not)
now the vac gauge sees what the FPR sees, ok?

key on only, not started,hot or cold engine. HERE.
best is hot engine, so the readings can be compared. and 800 RPM is 20inches running, cold the vacuum will be way lower,
the pressure will be the highest ever seen, this a key factor this first test, you reported, 40PSI, (mine reads 36)

but then start the car,
best is hot engine, so the readings can be compared. and 800 RPM is 20inches running, cold the vacuum will be way lower, AND HARD TO JUDGE)
the 40 your read must drop by 6psi hot, 800 rpm is hot, and 20" Hg vacuum is now.
you reported 35 running that is 5 PSI drop and is ok
if you gun the throttle the vacuum goes near 0, and fuel pressure jumps newer 40 (mine 36)
then you cut the throttle ,a huge vacuum is created, 26inch HG, and full pressure drops to 21psi. this is not in the suzuki book, it is tricky to do.

a wise tech, knows that the FPR has a 15 PSI dynamic range on this car, if not the FPR is bad, or vacuum wrong, or return line clogged(restricted)
the 2nd rule is the (again hot engine) is the FPR dynamic range, on hot engine 800 rpm normal idle speed.

To do the full FPR dynamic range one needs vacuum hand too to reach 21PSI
or play with the throttle, gun throttle to 3500 rpm about (fuel pressure rises ) then cut the the throttle see the fuel pressure fall like rock
lowest ever seen is 21psi. at 26inches HG, vacuum as the engine spools down. fast.

the engine makes huge powerful vacuum pump HOT (but not very well cold with IAC wide open wrecking vacuum)

the FPR is best tested with a hand vacuum pump, at FPR , engine idling,
it must idle keyon or the pump shuts off is why.

a shorter test if confident the new FPR is good (my guess the new FPR was never vacuum hose connected)
is do keyon pressure again. hot or cold engine, key on 3 times see max pressure keyon, not started.
my guess 40 is what you saw.
40 keyon. (mine reads 36) both mine and yours are in spec. but yours is 4psi higher,(cheap gauges do this easy but ok)
cheap gauges can be 4PSI OFF. EASY 10% ERROR. BUT WE CAN WORK WITH THAT.
when you start the engine hot, not cold, the pSI drops , 6 psi fuel press. EVEN A CHEAP GAUGE SEES THE 6 PSI DROP. at hot 800 rpm starts.
if starting a cold engine, I can not test any FPR cold sorry, only hot engines.

a cold start the vacuum is weak,(low inches HG, say 15 not 20) and the fuel pressure will not drop 6psi , less drop
making FPR testing impossible using only the engine, or if you must we use vacuum hand pump, to get 20inch HG at the FPR NIPPLE.

That is it.
conclusion, testing cold engines, is not easy , (or buy a hand vacuum pump at harbor freight)
Should I be able to blow throught the fuel return line?
yes 100x yes
that is why i said the first time any FPR reads high, this line must be checked for restrictions. this is fist, unless parts are cheap or free.

we do the return line bucket test or blow air test. for restrictions, just last week the guy here had the return line and evap line swapped at the tank
the line must free flow back to the tank, remove the gas cap so you are not fighting it, the vent system is closed,
that line can clogged, from bad fuel
it can be pinched at the steel frame line.
some hoses can collapse inside, and block fuel.

the FPR bucket tests all shops do.
fuel pressure gauge showing too high now,
stop engine
remove FPR return line
connect a hose from FPR return nipple and spare hose say a 1 galloon bucket.
start engine, if fuel pressure is now good, BINGO.
human lips blowing here/?
benzine is a solid known cancer agent, best is use long clean hose here. to blow.
the gas cap must be removed (it is solid block here) if removed the return like is 100% free flowing and if you blow now it must be.
as the gas cap block and the vent regulator takes over 1 PSI to overcome, humans do not do that well, (no ex GF jokes here)heheheheeheh

on a running car ever drop of fuel leaving the pump comes back to the tank, (return) minus what the injectors used.
so there is no return line pressure then. (it is less than the feed line)
but key off, not true. (gas cap off is he trick here)
1PSI , due to evap pressure regulator stoppage.
if the car had bad gas ever, this can happen easy
i do not know history.
also the tank and or the fuel pump rack can be rusted pile, of junk and many parts will fail fast
evap parts
vent parts can clogged.
and even that return line. can pack full of gunk of any kind, it is a loop system. and the whole loop will go bad with gunk or rust
and very common on this old car.
the latest. the fpr from advance was returned, the return nozzle was a inch or so longer than original and almost touched the metal return line causeing a slight kink i the short rubber hose, also no difference in performance.
the other day I let it run for about 35 minutes with old fpr back on it and it stopped smoking and no more black crap coming out exhaust.
today still no black stuff or smoke so i reran test, fuel 34 psi idle at fuel rail with engine warm, 18 vacuum idle engine warm, if i floor it it bogs vacuum drops to 0 then let of quick vacuum jumps to 22, pull vaccum on fpr with mighty might to 21 the fuel pressure is 32 vacuum 18.
disconnect maf revs up fine and no noticable fuel pressure or vacuum changes. oh and i can blow thru return line no prob.
first off they sold you the wrong FPR, for sure. the pipe be right, return, for 1992, to 1995 , the stores get so confused, 3 engines and many years.
it spins them up confused. why I do not know. that return pipe must match 1995 perfect.

the maf unplugged slams the ECU instantly in to limphome mode. rich burning, and no spark advance and low engine power,
about all that proves is 2 things, engine not dead and CAT not melted, blocking exhaust flows.

your FPR may be working, best i can tell but what is fuel pressure at 0 vacuum?
when you gun any 16valve G16B the vacuum tries hard to hit 0 inches HG, (which the atmosphere pressure landing inside the huge intake plenum box.'
this is when the fuel pressure hits max. (to not bog the pressure fuel will be 6ps greater. than idle. MUST.
the reason that happens is overcome the 14.5 PSI atmospheric pressure landing in the plenum box (WOT))
in fact the fuel pressure pushes against the fulll weight of our atmosphere, at wot. so the FPR DOES ALL THAT,.

the maf pulled causes huge injection rate increases AND CRUDE, (its like having 2 ECU, one normal and one for dead sensors,)
it only proves the injectors can flow good. with huge over injections , CAT OK, AND ENGINE MECH.NOT LAME /WEAK.

im tying to digitize your data now, from above post, 59.. AND VERY DIFFERENT FROM POSE 29
1-keyon(nostart,) not stated but would match WOT, nearly. spec,, 36 to 43,
2- idle, 34PSI a@ 18 iches, HG. spec=30-37) will be PSI below above, and is key fact to know. (not in the suzuki book this)
3-WOT, unstated @ 0 inches HG, sadly the 2 key readings were skipped, no fuel pressure here. OR KEYON. SAD.
4- and max vacuum 21 inches by hand, pressure 32 PSI FUEL. ( why not pump to 26"HG by hand? but 21 is near idle vacuum and so is redundant.
This last test 4 is not super important as are keyon(nostart) and WOT.

the WOT PSI is at the instant you open the throttle full, vacuum falls to 0 and the fuel pressure at this instant is KEY TO FULL power full normal injection rates.

i can not see your data, you skipped the 2 key factors that can bog any engine,

recap on what is not bad, or can be.(blind of new parts, just incase)
engine good.
cat not melted.
MAF not sure.?
fuel pressure wot,this session not known, post 59
huge crack in the intake pipe from MAF to TB (like mine had) bad main pipe gaskets, seen some fold over bend and suck air like mad. (vacuum leaks huge)
bad spark I dont know?, is uses scope with hV probe. bad ignition coil.
injectors half clogged, will bog any MPI car.
not fuel pump bad and passes shunt test

gun the throttle hard and fast how high did fuel pressure go Psi???????????????????????????????

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