Power loss while gentle throttle

[Alexbaba]

I have been reading almost every thread regarding similar problems as I have...But couldn't really solve my problem..

Car:
Vitara 16v G16B 5door JLX -94
About 190000km
JSAETD01V00150018
ETD01V

*When warming up it revs between 1500-2000, stabilizes after about a minute or 2, down to around 1200.
*Warm stable 800rpm
BUT
When pressing my pedal gently it lacks of power whatever speed I go. I can either let go/pedal to the metal to get rid of this "Jerk/bogg/powerdrop".
But when I want to cruise with gentle pressure on the pedal it keeps doing this. More or less from time to time.
And MPG feels pretty poor, maybe 1.2/L/10Km (I'm swedish

*TPS indicates
from 1-3
idle 0.45Kohm ----WOT 4.5 Kohm
(the other pins is whitin the recomended intervals)
*The cable shoe
0V, ~5V,0.2V, ~5V
(when key in ON position)
Also check engine when unplugged

*When removing MAP I get the check engine and rpm changes.
(cleaned)
* EGR looked like a fulltime smoking old mans lungs. But is cleaned(and fully function, if I press the silicone part it stalls, correct?)
* No leaks when spraying brake cleaner

I may have forgot something, and my english might be a bit incorrect. but I hope someone have a clue

Thanks!

[fixkick]

welcome!!!

I have been reading almost every thread regarding similar problems as I have...But couldn't really solve my problem..

Car:
Vitara 16v G16B 5door JLX -94
About 190000km
JSAETD01V00150018
ETD01V

*When warming up it revs between 1500-2000, stabilizes after about a minute or 2, down to around 1200.
*Warm stable 800rpm all normal.
BUT
When pressing my pedal gently it lacks of power whatever speed I go. (
I can either let go/pedal to the metal to get rid of this "Jerk/bogg/powerdrop". this says, the MAF is working good, (mostly) and TPS is bad.
But when I want to cruise with gentle pressure on the pedal it keeps doing this. More or less from time to time.
And MPG feels pretty poor, maybe 1.2/L/10Km (I'm swedish WELCOME to TEXAS !
where men are men and sheep are scared. LOL (quoting my side kick friend)

*TPS indicates
from 1-3
idle 0.45Kohm ----WOT 4.5 Kohm
(the other pins is whitin the recomended intervals)
*The cable shoe
0V, ~5V,0.2V, ~5V
(when key in ON position)
Also check engine when unplugged

*When removing MAP I get the check engine and rpm changes.
(cleaned)
* EGR looked like a fulltime smoking old mans lungs. But is cleaned(and fully function, if I press the silicone part it stalls, correct?) YES and good !
* No leaks when spraying brake cleaner

I may have forgot something, and my english might be a bit incorrect. but I hope someone have a clue who's looking. hell typing is for girls so....

Thanks!

the TPS never throws a code unless 100% bad, or 100% not calibrated correctly
it assumes the driver is 15years old and crazy as a bed bug, ( I was )

the TPS is just a carbon POT. a variable resistor.
and as the carbon wears bad it gets glitchy. in fact wears out where the speed the person loved to drive, say 45mhp country boy.
The ECU reads the output of the TPS and sees what is called delta. IF it sees you move the right foot really fast, it uses more ENRICH.
if the TPS fails to show truth, (fast foot) the engine bogs until the MAF catches up, the MAF is slow.
the air slug is fast and wins but the TPS cuts the slug off at the pass, and enriches faster.
think of the TPS as an early warning system. for fast foot and fast slugs of pure air. (pure, not pure but too lean)

I think your TPS is bad. (end of line)

but do clean maf hot wire, with the spray it, from say 1 foot, 300mm , away. (Carb cleaner or maf spray)
it can bet coked up and act slow. and will cause underfueling... (fast) I clean it first, then drive.

happy trails.
bench testing TPS is hard to see it glitch, they are tricky that way.

[Alexbaba]

Thank you!!

I was also thinking of the TPS, so nice with back up!

It feels like the car is not so jumpy when fully warmed up. Still the TPS? Or maybe something more thats not really working?
(I know there might be a lot of things not working perfect on this old car)

I have to special order the TPS here in sweden

I don't have any mechanic background, just a great interest and I'm handy with tools

[Alexbaba]

I ordered a tps from US, but as I had that one plugged in. My car still cant keep a steady RPM?! when I press the accelerator gently it revs high-drops to idle and over and over again unless I press hard/release...

If I unplug the TPS (both old and new one) it runs smooth! a bit weak going up hill. But pleasant to drive. But when I connect tps it jerks/rpm drops and up and is almost unbearable to ride.
Do you think there are a failure with the cables?
Any quick tests?

[fixkick]

Vitara 16v G16B 5 door JLX -94
the TPS must be calibrated. it's a tad tricky,, see my page on TPS cal? (it has the factory pages too)?/
http://www.fixkick.com/sensors/tests/TPS...html#MYWAY
if it dont close (idle switch), idle controls feature is disabled , if it opens late?, the ISC fights your right foot as you attempt to accelerate. (hesitations)
FailSafe.
http://www.fixkick.com/ECU/LimpHome/failsafe.html
Unplugging sensors, causes the ECU to drop to FailSafe mode, (rich,fuel, retarded spark timing , very ugly this mode is)
But ,most of these cars have 2 or more failures. and this can make fail safe , seem to make car run better. "relativity"

BTW, with TPS unplugged, the ECU uses, the MAF for the TPS, it takes MAF inputs and simulates a very very crude TPS sensor. this is how it works, and allows you to drive a car with dead sensors. see the CEL lamp blink on, that is the warning that the TPS is dead. (unplugged)

here is one case in point.
lets say, you have this failure (be it low fuel pressure?, or clogged injectors? or huge vacuum air leaks,?, the 16v MAF HATES AIR LEAKS )
RUNS LEAN.
the car has low power, because its lean all time time, (no scan tools for this car, so nobody notices the oxygen sensor stuck lean)
so you unplug the TPS, it goes to failsafe mode and goes richer , and like magic, gee this runs better.,
the classic,TWO WRONG ,Make a RIGHT. here . see that?
tool lean (failure ) + (too rich, failsafe) = is more close to normal... more close.


SCAN tool heaven.. (no more blind) way.
Now on my 1996, (or newer) we have a scan tool attached, I see CLOSED loop failed, hot idle, (BAD)
I replace my O2 sensor, and its still reading lean, no exhaust leaks.
i check fuel pressure and all sensors. all read correct. i find fuel pressure at 20 PSI, way too low. (oops wrong gas cap> missing vacuum breaker?)
or i find this huge vacuum leak in the intake plenum, oops all 4 injectors cushions are all cracked open, sucking air.
oops, the ISC air hose is cracked. (and lots more hoses, any and all MUST NOT SUCK AIR)
or like my 97, the main air pipe, on top the rear (unseen) mount broken, and the alum TUBE,had a huge hole in it, pinky sized.
in all cases closed loop failed, ISC had problems with idle (it can fix horrid lean) and the Long term fuel trim LTFT was stuck at +40% (adding tons of fuel and still cant get the 02 working right.)

the Typical, 1995 G16b , seen on the road.
has air leaks. all over, the plenum (MAF to intake valves)
the IAC my be stuck open (fast idle hot, or ISC hunting like mad because this IAC, NEVER closed at 150F.
the ISC may be sticking, most are. clean it.
A Bad TPS or not calibrated, or guessed at.?
Cracked #4 exhaust tube , sucking in fresh air, and now 02 sensor is reading way too lean forever.
Exhaust header (long tube) collector end, donut gasket, bad long long time ago. it's sucking fresh 20% oxygenated AIR all the time. O2 nuts again.
leaking or partial clogged injectors.
low fuel pressure. 36-43PSI running..is spec.. and regulates!. and FP regulator passes all tests in the FSM or my page.
http://www.fixkick.com/sensors/tests/FPress-reg1.html

the fuel pressure is not changing at idle. it must be steady, regulated. (if vacuum is steady the fuel pressure must be steady)
and must change pressure (drops) at wide open throttle. the REG is a 1:1 device, (fuel to vacuum)
1 PSI drop in plenum air pressure, nets a drop in fuel pressure of 1 psi. (or bar to bar pressure ,metric, or KPa to Kpa.)

This ECU can not see fuel pressure, so it must be correct at all times. (very unlike newer cars, with no loop for fuel lines)
if the FP regulator fails, say , stuck low, the ECU will UNDER INJECT FUEL. (failsafe, mode, may hide this)
this is the weakness, in this very old Suzuki system.

how is that? do ask questions.

this tool can help. (the only one on earth, (cept maybe a used $2000 tek1 scan tool 20 years old)

http://www.rhinopower.org/diag/sdl_if.html

[Alexbaba]

TPS is adjusted correct...
ISC correct resistance and working...
Maf cleaned and measured correct...
No difference in idle As I can see/hear when spraying brake cleaner.. (havent found any visible failures)

I cant see if PO changed O2 sensor in car history....

Is there any tests to see if that one works, or do you think it can be the case?

*As the car boggs when tps is plugged in. A steady foot at each gear will result in heavy bogs for some seconds. It will try to catch up, but boggs again unless i push pedal to metal/release...

*When tps unplugged, car runs better (as you said, two wrongs make a "right")
a bit high idle hot, 900-1000
*Perfect idle whenTPS plugged in, but boggs out when around 2000 rpm...drops from around 2000-25000 down to 900 and up (over and over)

I havent checked the fuel pressure though...as I dont have whats needed...BUt can that be the issue when car runs "good" withoug TPS? the sparkplugs seems good...

injector cantacts (those two under TB/air intake )are pretty dirty/oil so I will remove and clean, but need the car daily for work..!
Can that be the issue ?

Your site has helped me alot! BUt I just cant crack the issue...!

[fixkick]

low fuel pressure,
the 02 is inactive when accelerating so not 02. mostly its just the MAF , air flow , dictating fuel injection rates. then.
low fuel pressure or clogged injectors.
94 G16b
with the TPS unplugged, injection pulse widths are excessive, and can hide, low fuel pressure or clogging.
with the TPS plugged in , do you have full WIDE open power, up a hill. (manual or stick tranny?) in 3rd gear for stick tranny, up hills uses max fuel.
injector cantacts (those two under TB/air intake )are pretty dirty? the injector connectors are dirty? or just outside of it?

if the fuel pressures drops, too low the MAF and ECU dont know that, and fueling rates drop.
the spec. pressure is 30-37 PSI. idling , 19inches /HG. vacuum.
when you go WOT, the pressure, rises (+6 PSI) on the injector to compensate for increased atmosphere pressure at the injector tips (plenum is open now)
so if say the FPreg is bad. and that dont happen, the fueling will go lean. (not limphome, and limphome is the least documented feature of Suzuki, poor)

the key on pressure spec, is 36 to 43)

lets say your FPreg is 36 psi , key on 3 times. no start.
then you start engine, at idle its now 30. it will be 6 PSI less due to the 1:1 rule. vacuum to pressure rule.
when you drive real fast and cut the throttle this car fuel pressure, will drop in a hard vacuum, by 14psi from key on pressure. 34-14= 20 line pressure.
then when wide open throttle the plenum nears 1 atmosphere so pressure will be near key on pressure, say , 36.
if the Fpreg goes bad. (lots of ways sadly) but if bad. it can stuck low? or be dead. or? leak.
if it sticks low engine will bog. The ECU, wants near 36 psi during that ACCELERATION EVENT. this higher pressure fuel overcomes the atmospheric pressure of at injector tips.

on new cars this pressure is monitored, and you will get codes. if out of spec. but not this car ,codes=DTCs/


if the car is a daily driver, most likely that fresh fuel every day ,the injector are clean.
but what about FPREG>>?>>>???

http://www.fixkick.com/sensors/tests/FPress-reg1.html

i should make a fpreg chart, yes...... too soon.

Gringo and ROTW (rest of the world)

[fixkick]

The ECU can not correct for a bad FPreg.
mostly.
it might , if lucky, light cruise using the 02 sensors, and the +/-40% dynamic range of that.
but not accelerating.. the pressure must be correct.

---

correct my mistakes, if any, its new,

---

the first check.
is?
FPREG
1: fuel leaking out vacuum line , pulled?
2: vacuum diaphragm leak down test. no leak down allowed. hand vacuum tool.
3: then the hand tool and fuel pressure tests. check its range. per graph.

[Alexbaba]

OK, Well after many hours I have now come up to this.
My topic feels a bit wierd...
More like; car will bog under light steady throttle

EGR:
*stall test OK. Is there a point of doing the "live test"?
*Cleaned

FPreg: I have no tools for this, neither any mechanic store nearby...have to order
*But no fuel leak to vakuum hose
*No change to RPM when pinching return hose...

TPS: Calibrated as accurate I can, position and measured in (correct) range, idle to wot
* When plugged in I cant hold a stable 2000 RPM, drops about 500-900rpm and up again.*
*unplugged no idle (1000rpm) BUT I can hold it Stable at 2000 RPM

Cooling system:
*No Smoke from tailpipe, when hot
*Gauge indicates just below mid in temp scale.
*Sometimes the expansion tank is full to the top (dry RAD top as I can see), sometimes almost empty and RAD full..?

Vakuum: I haven't found any Vakuum leaks... and no clogged up hoses...yet.

RPM:
*Cold start around 1800 for a couple of mins
*Hot around 800 sometimes down to 600 and no misfire och bogging
*When moving, clutch pressed around 1500 RPM
*Pinching ISC hose drops to 400RPM
* Car feels heavy/powerless when going on low RPM on high gears, (read gear 3 on 3500 RPM, dosen't get full power until 4500rpm (normal?)
that makes it hard to change gears smoothly as I have to meet thottle/clutch for a quite long time, since it lacks of power...

MAF: Cleaned, and measured voltage/resistance OK
*Car will not be able to drive unplugged

Oil: No signs of contamination from coolant,dust etc. Stabile level.

ISC:
*Seems to work, pinching hose rpm drops as said.
*cleaned
IAC:
* I plugged the throttle to IAC hole, no change HOT
* I haven't checked or cleaned it...

Regarding injector cables its only the outer shell thats dirty.
there might be some symptoms/checks I forgot..

I just cant solve this riddle

[fixkick]

94 G16B. WHICH TRANSMISSION?? 5sp?

94 G16B.
OK, Well after many hours I have now come up to this.
My topic feels a bit wierd...
More like; car will bog under light steady throttle

EGR:
*stall test OK. Is there a point of doing the "live test"? (the live tests , then prove, the EGR works moving, but just look for DTC 51, if present live fails.)
*Cleaned

FPreg: I have no tools for this, neither any mechanic store nearby...have to order.. harbor FRIGHT tool , has it for $20 and the adapter FITS !
*But no fuel leak to vakuum hose
*No change to RPM when pinching return hose...
(no and effect is normal, but on pinching, with hand gunning engine, that would make AFR go lean)
pinching the hose, locks in the vacuum at PFR, (id diaphram is good and not cracked) so nothing changes. but if you gun engine like that.
the plenum goes to near full atmospheric pressure. this will be lean because the pressure most rise,(fuel) as you go to or near WOT.


TPS: Calibrated as accurate I can, position and measured in (correct) range, idle to wot
* When plugged in I cant hold a stable 2000 RPM, drops about 500-900rpm and up again.* HOT OR COLD?
*unplugged no idle (1000rpm) BUT I can hold it Stable at 2000 RPM
running in limphome is of no use at all in diagnosis. nearly so... and doing so , kills to sensors at once, idle switch and throttle angle. bad that is.


Cooling system:
*No Smoke from tailpipe, when hot
*Gauge indicates just below mid in temp scale.
*Sometimes the expansion tank is full to the top (dry RAD top as I can see), sometimes almost empty and RAD full..?

Vacuum: I haven't found any Vacuum leaks... and no clogged up hoses...yet.

RPM:
*Cold start around 1800 for a couple of min's
*Hot around 800 sometimes down to 600 and no misfire och bogging (600 is wrong, this means the ECU sent a command (not limphome) to the ISC and it failed to open or AFR is way too lean) the trouble is , no scan tool or scope to check AFR.
*When moving, clutch pressed around 1500 RPM
*Pinching ISC hose drops to 400 RPM (so ISC is flowing hot,good)
* Car feels heavy/powerless when going on low RPM on high gears, (read gear 3 on 3500 RPM, doesn't get full power until 4500rpm (normal?) no.
that makes it hard to change gears smoothly as I have to meet throttle/clutch for a quite long time, since it lacks of power...

MAF: Cleaned, and measured voltage/resistance OK
*Car will not be able to drive unplugged (again limphome is not to be used to test cars, doing this burns up CAT fast)

Oil: No signs of contamination from coolant,dust etc. Stabile level.

ISC:
*Seems to work, pinching hose rpm drops as said.
*cleaned
IAC:
* I plugged the throttle to IAC hole, no change HOT (VERY GOOD, no bad IAC) !!!
* I haven't checked or cleaned it...

Regarding injector cables its only the outer shell thats dirty.
there might be some symptoms/checks I forgot..

I just cant solve this riddle

its lean,, with no scan tool we can do this
1: all inputs to ECU good.
2: there for, fuel pressure is low,. or injectors clogged

i think its lean. and i GUESS its lean , at WO?T, you HAVE LOW POWER in 3rd gear up hills.
if yes, and MAF test Passes, then bad fuel pressure, or clogged injectors.

the ECU can not inject correctly, with out of spec, fuel pressure.
20 PSI is no good.
did this car have bad gas on one point ?????

---

please type away, this is a car fix site , not a Grammar Nazi test zone. or any thing like it, even use wrong names for parts we can sort all that.
i wish my spanish was as good as your english !
welcome and enjoy and ask any questions you what.

im sure now, there is no HARBOR FREIGHT STORE THERE.
The hose that fits has a 6mm thread on the end. that fits the filter.
fuel.