Engine Stalls

[Joe Tracker]

Need some help. My engine will miss/stall/die after driving 15 or 20 minutes or so. The check engine light is not on and no codes are in the system (I took it to a parts store and they out their code reader on it).
Prior to this, several months ago, I had to begin manually bringing the RPM's up before shifting into first gear to prevent it from stalling or bogging down.

After replacing the in line fuel filter the problem is still there but the misses/stalls are not as abrupt and I no longer need to manually increase RPM's before shifting into 1st gear. If I continue driving after the misses/stalls then the engine will ultimately die. If I let it sit for a few minutes, I can drive it but then the entire cycle starts over again.

My vehicle is a 1999 Chevy Tracker with a 5 speed, 4x4 with transfer gear case, and 1.6 liter engine. I am the fourth owner. One owner placed the care in storage for at least a couple of years (I do not know if they did that correctly or just drove into a storage area, turned it off, and walked away). When I bought the car in January of 2015, the previous owner had just replaced the

EGR valve,
water pump,
timing belt,
cam seal,
crank seal,
accessory drive belt.

The car 126,000 miles on it when I purchased it. It now has 145,000 on it and has run great until these issues happened.

I do occasionally flat tow the vehicle. When I flat tow I place the xtr gear case and gear shift in neutral. I stop at least every 200 miles, start the car, place the gear shift into first gear, and let it idle for several minutes.

I am thinking that I need to drop the gas tank and replace the fuel pump and/or in-tank filter (I am assuming it has an in-tank fuel filter). The engine air filter looks fine.

Can anyone give me advice root cause and appropriate next steps?

Thanks,

Joe

[fixkick]

hot stalls so means has full power cold? if yes this is key (fuel starvation)
do a tune up? spark plugs wires set (19 year old wires are no good) cap and rotor,
now that spark is good, next is fueling.
injector cleaner, in the tank, Techron (by Chevron),. may help. (it has powerful solvents unlike most others sold)

car storage can can clog injectors easy, the injectors 10 micron sizes screens inside to.... they must be clean.
low fuel pressure is next. must be at spec.
and good MAF sensor, easy test, with dmm voltmeter.'

good engine, compression good,
good spark and timed right.
next is clean fuel.
then clean injectors (im not sure where your filter is , but the tank has sock on the pump input to stop gravel and rocks. LOL
then fuel pressure, it must be in spec, at key on and idle. 2 tests.
last is maf test. or clean it.

the engine needs a cam belt at 60k miles, 128kmiles is hopeless impossible. if it slips, the cam goes retarded and most times fails to start or floods fast, and stalls cold.

[Joe Tracker]

Yes - it has full power cold. It drives great cold. And the car has run flawlessly since I bought it and up until this point. So I guess it is fuel starvation (and that is what it feels like!).

1. How do you recommend I clean the fuel/tank? If I need to drop the tank, do you have a reference/instructions?

2. Then I will try the Techron and see if cleaning the fuel system/injectors will do the trick.

3. I have a digital multimeter. what is the test for the Mass Air Flow sensor?

I doubt a tune-up is needed. I bought the care from a 76 year old guy who knows cars. He had his mechanic go through it thoroughly. The only issue when I bought it was a leaking front crank seal. The old man apparently had drawn a line and did not want to mess with the crank seal. I have had the crank seal replaced (big $$$'s) . Now there are zero leaks!

Thanks,

Joe

hot stalls so means has full power cold? if yes this is key (fuel starvation)
do a tune up? spark plugs wires set (19 year old wires are no good) cap and rotor,
now that spark is good, next is fueling.
injector cleaner, in the tank, Techron (by Chevron),. may help. (it has powerful solvents unlike most others sold)



car storage can can clog injectors easy, the injectors 10 micron sizes screens inside to.... they must be clean.
low fuel pressure is next. must be at spec.
and good MAF sensor, easy test, with dmm voltmeter.'

good engine, compression good,
good spark and timed right.
next is clean fuel.
then clean injectors (im not sure where your filter is , but the tank has sock on the pump input to stop gravel and rocks. LOL
then fuel pressure, it must be in spec, at key on and idle. 2 tests.
last is maf test. or clean it.

the engine needs a cam belt at 60k miles, 128kmiles is hopeless impossible. if it slips, the cam goes retarded and most times fails to start or floods fast, and stalls cold.

[fixkick]

what others did or not, is not if any importance IMO, (lacking receipts)
all cars ran great new, but not now, 19 years later... all fail now , you're in that class how, the 19year old class . (most cars this old have 10 things wrong and now stackedup., (hard to find)

since it runs OK cold.
that tells me spark is probably ok.
what is wrong is hot. running, if it bogs its fuel, bogging is not violent misfiring, bogging is like pulling a dead 10,000 weight but also can feel like hesitation that is also loss of fuel.
what we do, is check fuel pressure first.
why
well the whole EFI system is rendered useless (near) lacking spec pressure
and #2 the ECU can not measure rail pressure, nor know how to compensate for the wrong pressure , as it is blind to that.
the 02 can trim this, out but the 02 sensor is off line , accelerating and at WOT, wide open throttle, so that means fuel pressure must be in spec.

we use fuel pressure gauge at the fuel RAIL or at the filter test port to do that.
on all 16v there are 3 tests (minimum) keyon pressure after 3 keys on, no start. then idle pressure then see what it does gunned to wot for 1 second.
all 3 tests must pass. (type pump in my search box for all 6 tests+)

the maf test is next or even first lacking tools to do both.
at kickfix.com I type maf in the search box and land at

http://www.fixkick.com/sensors/92-95MAF/...sting.html

the car sat too long, and that will make fuel go bad, for sure modern USA gas what ethanol in it at 10% , this gums up injectors !

if pressures are good and maf ok , maybe the injectors screens are packed, (takes untrasonic reverse cleaning to fix the hard ones, techron can fix)

first clean the maf, using maf cleaner (CRC) and keep the nozzle straw 8 inches away from the fragile element inside, best is spray 3 times, let soak 1 min between sprays to get it softer that gunk there.

maf pin 2 , meter there and ground
key on volts
idle
and gunned
if A/t SHIFT BOX, USE IT AS DYNO,, DO THE TRANSMISSION STALL TEST WITH MAF TEST AT THE SAME TIME, SEE HUGE AIR FLOWS. BUT i see yours is 5speed.
the maf output will be max at 95HP,


here is me testing my MAF , live and up a hill and attempting to make max HP. and see what a good maf does
fuel pressure at spec, FPR working 100 percent and raise fuel pressure by 6psi, at wot.
and you get this cool spike out of Mr,. maf (my scan tool can log data on any sensor, in time, or all sensors at once, i can the import it to Excel and plot it) you can see my doing shift points here 5 speed 96


the maf weak acts just like low fuel pressure or 4 injectors 1/2 clogged
that fact is way we do 2 tests to prove which it is, a bad FPR is most easy to replace and not $1000 cost like MAF from suz. Cardone1 sells them rebuilt for 400.

[fixkick]

the pump shunt test must be done, if the pump is weak, , the pump is bad.
if the shunt passes
and the pressure are wrong at idle or wot.
then the FPR is bad, in most cases
and is super common on all 19+year old sidekicks or vitaras or trackers. (sunrunners too)

[fixkick]

that spike is grams per minute of air, flow, mass air fold sensor.
it only goes that high if 95hp can be done. and there are lots of ways for that to fail. even with a new maf.
a chicken and egg deal that.

[Joe Tracker]

I want your feedback. I have completed the following fuel tests. Where do I go from here? Also, the FPR on my 99 Tracker looks like your photo of the 8V instead of the 16 valve (the vacuum nipple on my FPR is dead center and facing forward instead of coming off the bell to the side).

Fuel pump tests completed:

1. 3 sec buzz test,
2. cap off (made no difference)
3. static pump (36 psi on the nose)
4. Leak down (held well above 25 PSI for several minutes).
5. Engine running (the psi did change when I gunned the engine, but tended to return to 36 psi over time).
6. Dead head shunt - 60 psi when I pinched the fuel return hose.

I also completed the FPR tests:

1. No fuel leaking from vacuum nipple (diaphragm intact).
2. Fuel at 45 psi when FPR vacuum line disconnected from the FPR. (returns to 37 psi as soon as vacuum line is reattached).
3. There is 19 Hg of vacuum in the FPR vacuum hose with the engine idling.
4. Testing the FPR using a MightyVac gage/pump and the vacuum hose to the plenum plugged:
a. The vacuum at idle in the hose to FPR was 19 Hg (I live in Arkansas at an altitude of 312 feet).
b. It took 22 Hg of vacuum from the MightyVac to the FPR vacuum nipple to return the fuel pressure to 35/36 psi.
c. At 27 Hg the fuel pressure was 32/33 psi.
d. The FPR passed the leak down test easily (8 Hg for 30 seconds).

I am prepared to do the MAF tests next, but want your advice.

Thanks,

Joe Tracker

[fixkick]

1999 Chevy Tracker with a 5 speed, 4x4 with transfer gear case, and 1.6 liter engine. (hot engine loss of power)
your FPR works great. so is the pump,
i forgot to ask when the engine wants to stall , does the fast right foot, prevent the stall and every time?

clean the maf yet? keep spray cleaner about 8 inches away from the element. clean it like 3 times, 1min or so between cleanings, let the cleaner sink in
then test it with a voltmeter.
if maf tests ok , must be injectors clogged.
voltmeter tests maf
and test 1, with engine idling hot, gently rap the maf sensor with back side of screw driver, blade in hand, RPM's must not change or the maf is damaged inside.
happy hunting !

[fixkick]

ran great until, it didnt,
but if the PO let the gas go bad, that gas can turn to varnish , and coat every thing from from tank to the end point , injectors
if can get worse, easy with fresh gas added all those cleaners in the gas, cleans off that varnish and may then clog the system later.
a delayed effect.
but i guess the car ran ok for 2 years, every day, or 4 times in 2 years.? how long did it drive ok , when you owned it.
if the car ran ok for 2 long years, every day , id think the above varnish issue is a none ISsue.
but needs to be said, on any long term parked car,

was the tank full for those years parked, (day 1 you got it) or 1/8th full?
the lower the tank level the more likely the fuel went bad.
2 years is about max on gas life, unless special additives are put in the fuel before storage. (STABIL)
The gas cap must be good, and it's vacuum breaker working, .

engine good. compression
sparks good, no scan codes P03xx of any kind driving it hot, and running the scan tool and for sure no pending codes, many codes take 3 driving cycles to set, that is why there is pending button to push in the scanner to see NOW, whats happening NOW,
btw all scan tools sold (real, not $15 code readers ) all work on this OBD2 car. (and all sensors can be scanned , at any time, even driving)
THINGS:
Fuel pressure at spec, it is.
FPR works good, it does.,
pump shut test passes, so pump is ok

leaving map , then injectors clogged.

one other possible is gross ,main induction air leaks.

from the rear of the mAF to the intake valves, there most not be any leaks there (just the ISC/bleed screw are allowed, idle controls only)
if you get a very bad air leak, this leak bypasses the MAF and now the MAF lies. called illegal un-metered air.
my 97 had this, the huge air pipe on top broke.
the PO, removed the 2 bolts securing the main air pipe mounts. this allowed it to bounce and broke the alum. mount clean off that huge pipe, and it sucked air like mad there(backside it was, nicely hidden..... ouch)

then the main air box was deleted, and he used this silly looking motorcycle air filter, and now the mAF bounces up and down and beat it to death.
a $1000 part at suzuki, not too smart wrecking any MAF like that. (IMO)

I call those events, can't win for losing,......
also seen the boot from left (face it) main air pipe, boot missing or damaged, and again sucking air like mad and maf cant do its job, even with a good maf, even new.
or just let that boot sit loose sucking air, not using the clamps there are designed.
my 04, that same boot was installed wrong and warped, to too it all apart and wow this huge gaping hole is there as the boot, folded and sucks air endlessly.
took a new boot to fix it, it was a wreck. (due to bad service)

this engine most not be allowed to suck in metered air. (maf)

[Joe Tracker]

ran great until, it didnt,
but if the PO let the gas go bad, that gas can turn to varnish , and coat every thing from from tank to the end point , injectors
if can get worse, easy with fresh gas added all those cleaners in the gas, cleans off that varnish and may then clog the system later.
a delayed effect.
but i guess the car ran ok for 2 years, every day, or 4 times in 2 years.? how long did it drive ok , when you owned it.
if the car ran ok for 2 long years, every day , id think the above varnish issue is a none ISsue.
but needs to be said, on any long term parked car,

was the tank full for those years parked, (day 1 you got it) or 1/8th full?
the lower the tank level the more likely the fuel went bad.
2 years is about max on gas life, unless special additives are put in the fuel before storage. (STABIL)
The gas cap must be good, and it's vacuum breaker working, .

engine good. compression
sparks good, no scan codes P03xx of any kind driving it hot, and running the scan tool and for sure no pending codes, many codes take 3 driving cycles to set, that is why there is pending button to push in the scanner to see NOW, whats happening NOW,
btw all scan tools sold (real, not $15 code readers ) all work on this OBD2 car. (and all sensors can be scanned , at any time, even driving)
THINGS:
Fuel pressure at spec, it is.
FPR works good, it does.,
pump shut test passes, so pump is ok

leaving map , then injectors clogged.

one other possible is gross ,main induction air leaks.

from the rear of the mAF to the intake valves, there most not be any leaks there (just the ISC/bleed screw are allowed, idle controls only)
if you get a very bad air leak, this leak bypasses the MAF and now the MAF lies. called illegal un-metered air.
my 97 had this, the huge air pipe on top broke.
the PO, removed the 2 bolts securing the main air pipe mounts. this allowed it to bounce and broke the alum. mount clean off that huge pipe, and it sucked air like mad there(backside it was, nicely hidden..... ouch)

then the main air box was deleted, and he used this silly looking motorcycle air filter, and now the mAF bounces up and down and beat it to death.
a $1000 part at suzuki, not too smart wrecking any MAF like that. (IMO)

I call those events, can't win for losing,......
also seen the boot from left (face it) main air pipe, boot missing or damaged, and again sucking air like mad and maf cant do its job, even with a good maf, even new.
or just let that boot sit loose sucking air, not using the clamps there are designed.
my 04, that same boot was installed wrong and warped, to too it all apart and wow this huge gaping hole is there as the boot, folded and sucks air endlessly.
took a new boot to fix it, it was a wreck. (due to bad service)

this engine most not be allowed to suck in metered air. (maf)

Thanks for getting back to me. To answer your questions:

1. No - you cannot use the throttle to power through the stalls. The engine just quits and the tach goes to zero. You must pull over a let it sit a few minutes. It will not re-start unless you let it sit for a few minutes.
2. I do not know the conditions under which it was stored - full tank of fuel or otherwise.
3. I have added the Techron cleaner to the fuel, but the tank was 3/4 full. I am at half a tank now. Perhaps I will add another bottle!

I will clean and test the MAF and check for air leaks. I have a new DMM I will use on the test. Then I will be back to you.

Joe Tracker