1995 Tracker LSI 16v MPI starts, runs for 2 to 4 seconds then dies

[Happycampsterers]

I have done the following troubleshooting test to help identify what is causing this Tracker to stop running shortly after it is started. It will run for 2-3 seconds (sounds strong, no miss).

Yes it was a barn find, not running for over a year, blown head gasket, repaired 150 psi in all cylinders cold...Cat was completely clogged..exhaust path clear now..

Fresh fuel and filter, cap, rotor and wires..
Fuel pressure at filter 38 psi with good volume.
Fuel pressure at rail 38 psi.
Clean fuel injectors all 4 pass spray test, and NOID test when running at start. Hot foot helps, engine will continue to run with test fuel...
TPS-pin 2 @ 50 ohms throttle stop, infinity @ slightly open throttle
pin 3 @ ~ 1K ohms throttle stop, increases linearly to ~ 4k ohms
pin 4 @ ~ 5k ohms

DTC jumper in gives code 12 and DTC jumper out CEL comes on @ key on and goes off after start.

All pins back probed @ ECU tested out accordingly with the "92-95 1.6L 16v ECU static test USA/Canada OBD1" data provided with this site (THANK YOU!) with the exception of pin B12, this pin at ECU is always 0v. Static test data says it should be B+ key on and B+ to 0v running varied by throttle position. Is this a bad ECU? Or is the issue downstream of this output? How do I troubleshoot this condition?

[fixkick]

WELCOME !
95 G16B

I have done the following troubleshooting test to help identify what is causing this Tracker to stop running shortly after it is started. It will run for 2-3 seconds (sounds strong, no miss). (but what does it do , tried again, now?) run 2second?

Yes, it was a barn find, not running for over a year, blown head gasket, repaired 150 psi in all cylinders cold...Cat was completely clogged..exhaust path clear now..

Fresh fuel and filter, cap, rotor and wires..
Fuel pressure at filter 38 psi with good volume.
Fuel pressure at rail 38 psi. (what is it keyon then running psi, this tests the FPR actions and is super important on all MPI(
Clean fuel injectors all 4 pass spray test, and NOID test when running at start.
Hot foot helps, engine will continue to run with test fuel...
All that looks ok, but FPR tests, missing. TPS is ok, but TPS wont stall engines, yes it can fail and prevent cranked starts.

TPS-pin 2 @ 50 ohms throttle stop, infinity @ slightly open throttle
pin 3 @ ~ 1K ohms throttle stop, increases linearly to ~ 4k ohms
pin 4 @ ~ 5k ohms

DTC jumper in gives code 12 and DTC jumper out CEL comes on @ key on and goes off after start. (but what is the code, at the moment of stall????)

All pins back probed @ ECU tested out accordingly with the "92-95 1.6L 16v ECU static test USA/Canada OBD1" data provided with this site (THANK YOU!) with the exception of pin B12, this pin at ECU is always 0v.
B12 is a 200hZ square wave. (the pair) for ISC. (electric iac) only a scope works there or DUTY meter, generic DMM on DC can not see 200hz, blind to that.
the AC mode, will try to RMS value that, and fail.
I have the real signal on my ISC page.
http://www.fixkick.com/IGN_timing/CAS-91.jpg
here it is in all its glory, if the ISC dies, engine goes (scope 0v) to 400rpm or stalls, toss coin.....but hot foot every time saves this. after all isc is just an air valve. so you can pretend you are one. at any time, with right toe.


Static test data says it should be B+ key on and B+ to 0v running varied by throttle position. Is this a bad ECU? Or is the issue downstream of this output? How do I troubleshoot this condition? this book comment is bad, it needs to say ISC duty varies with engine load, and goes off line , at cruise.
and then wakes up when you lift throttle foot, and the ISC goes in to, anti-neck snap mode, (dash potting violent deceleration ,prevents that... )

when you cut the throttle you never want to go to zero air supply, this too is a feature.

Hot foot helps (what does that mean?)
it has 3 anwers.
1: easy and can keep engine running full time this way.
2: hard,
3: impossible.

hard, can be 3 things, gross misfire, EGRs stuck open (cat missing?) or too lean to run,. or black spark plug tips, x4? called flooding.
when engine stalls, are plugs black? or bone dry white. or soaking in fuel

why only 150psi, are you not at sea-level, all mine do 180 min. and up to 195psi hot.
(cam timing one tooth off, is bad.)
yeah cold can be lower,,, sure. must be cold. best is do it warm or hot. but its moot point if not bad.
conclusions
seems what.
engine ok.
sparks ok
fueling bad (rich or lean , not known)
not ISC because hot foot fails to take command so is not loss of AIR.
CEL flashs 12s at stall, you can drive a week with code 12s flashing so , just keep the jumper there, until engine efi runs right. is best deal.
runs on test fuel ,this real gas or instant start in a can, as the later can clear flooding and fool the tech.
check spark tips, read them. at stall.

The ecu will not cut injection , unless it sees spark fail. (cmp fail) with codes 41 or 42 the software cuts all fuel, NOW.
cranking has other rules, when cranking you can open the throttle 100% and the ECU cuts fuel, w

my guess is , injectors , cut fuel
or they are flooding it. (just one or all 4 is clue too)
knowing which it is , is the cause and solution..

keep the jumper in, the DIAGNOSTIC PIN ,at stall. see if cel flashes bad codes. then,..... this is super easy to do.
all this assumes good fuel in tank, pump,lines and injectors.

[fixkick]

questions, the injectors were professionally cleaned
in that the 10 micron screens inside were back flushed,? using ultrasound is top way.,
all barn founds, the screen are full of junk, packed. or 3/4s packed allowing start and die.
they only need to flow at 10hp flow rates to idle.
keep in mind cold starts use a crude rich fuel mix , cranked, this can hide partially clogged injectors, until it runs , goes lean and starves , in idle mode.