1996 Geo Tracker 1.6 16v Stalling when Warm

[Garemie]

Hello all!

New to kick-fix, though have been using it as a reference for some time.

I'm rather stumped, when cold, the idle is totally eratic, sometimes 1500, sometimes 2100, sometimes 2800.

Then once warm, it will idle around 800-1200 (sometimes surging between the two, not really sure what triggers it) and then after I touch the throttle it will either bog out and die, or drop to like 300rpm and barely recover.

I used an OBD scanner and saw an ISC code, and EGR code. I took them off and cleaned them, reset the codes and now after driving a while, the codes have not come back, however, the same symptoms apply.

I do not quite understand how to test the EGR on this car, because it's got a metal plate that cannot be pushed on in order to do the stall test.

I thought perhaps the timing belt had slipped, so I replaced it last night, but it was fine. However, I went to time the motor this morning, and the timing jumps around so much, I didn't really know what to do. In the few rare occasions that its actually running at 800RPM, it would jump between 2-10 BTDC.


I'm so confused

Please let me know if I missed any vital information.

Thank you in advance, and I'm happy to finally joined!

[fixkick]

hello and welcome !!

you have a real scanner? that can see all PID's (like ECT, closed loopstatus, IAT, LTFT, TPS angle, etc?) not just a code reader?

that surge means (ecu caused) is because the ECU can not hold idle a 800 rpm , so it hunts the ISC valve (air supply) to find 800 and cant.
my guess is the intake system on this engine is leaking air, from MAF to intake valves. (end to end can leak) and go lean.
EGR is missing and has metal plate in place of EGR main?
or the ring plate (steel)inside the frame skeleton, is stuck , if yes this is a stuck closed EGR. (bad)

yes, the cars ECU must have the timing freeze jumper inserted, to set timing (spark)
the jumper is called DLC connector next to right front head light.
that jumping is normal, that is how (just 1) the ECU , makes idle run so good. (perfect mixtures)


you do have 2 problems on the engine, EGR is last, in fact fixing the other with EGR stuck closed, is more easy.
seem you timing belt did not slip, with 2degrees there. if it slips it goes way cam shaft (spark) retarded and rpm drops like a rock. (usually)

here is the results of a full 96 scan
any scan tool can do this, ignore graphs, that is my fancy software doing that , and is not needed.
http://www.fixkick.com/ECU/Authority/A_F..._scan.html

so when scanning does TPS work, match foot actions. (right foot throttle)
does ECT attain 180F hot and hold there.
all others checks hot engine.
MAF reading at idle, ? and what can you get gunning the throttle?
RPM will be wrong, (yours is )
Do you get closed loop status, at idle, (i bet not)
what is LTFT at idle hot (long term fuel trim) -5% (or -8) but not + 40% (its polar readings,)
better tools can see the 02 swing, many times a second.

no my wild guess.
vacuum leaks.
where, that is the question.

IAC stuck open will also cause this.
IAC is thermal, mounted under the throttle body.


300RPM is bad. maybe the EGR is leaking (main valve,) it can be hard to remove, those 2 ,6mm screws. (if off, get the valve to open by hand and snap shut)

even the cheapest $10 scan tool can read a 1996 fully.
??? ideals.
the bogging is bad sign.
Egr stuck open or weak FAM (ecu can only report (DTC) dead maf, not weak)
or very horrid air (vacuum leaks)

http://www.fixkick.com/sensors/EGR/egr-main2.jpg

full 96 egr report
http://www.fixkick.com/EGR-Gen3.html


DLC; jump pin 4 to 5 for freeze (6pin conn, next to R/F head light)
http://www.fixkick.com/IGN_timing/IGN-FREEZE.HTML

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if the IAC leaks, we will need to prove that with clay here
http://www.fixkick.com/fresh-air/Slide_S...Body1w.jpg

but you can not run engine with the AIR pipes off like that. (this would make the MAF read 0)

id do full scan first. do get a better handle on what's going on.

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for now , get the EGR main closed, 100% .
fix real problems, (bogs tops that list) then attack EGR last.
engine will have full power, like that.
the 96 has rubber main intake pipes behind MAF to engine, are they cracked? and boots.

[Garemie]

Thank you for the prompt reply!

you have a real scanner? that can see all PID's (like ECT, closed loopstatus, IAT, LTFT, TPS angle, etc?) not just a code reader?
Yes, I purchased a full scanner.

EGR is missing and has metal plate in place of EGR main?
or the ring plate (steel)inside the frame skeleton, is stuck , if yes this is a stuck closed EGR. (bad)
I don't really understand, but there's a metal plate that doesn't move between the back of the EGR and the rubber gasket. Is it supposed to move?

yes, the cars ECU must have the timing freeze jumper inserted, to set timing (spark)
the jumper is called DLC connector next to right front head light.
that jumping is normal, that is how (just 1) the ECU , makes idle run so good. (perfect mixtures)

Got it, timed it correctly now.

so when scanning does TPS work, match foot actions. (right foot throttle)
Yes, it does.

does ECT attain 180F hot and hold there.
It really depends, sometimes it's 165 or so, and others its 185.

MAF reading at idle, ? and what can you get gunning the throttle?
MAF at idle is 1.8 G/s and at 3000RPM it is 7.5 G/s


Do you get closed loop status, at idle, (i bet not)
Oddly enough, I do, until I hit the throttle, then sometimes it goes back to open loop, and other times it just stalls.

what is LTFT at idle hot (long term fuel trim) -5% (or -8) but not + 40% (its polar readings,)
I'm not really sure why, but it only showed fuel trim when it was cold, once it was warm it showed 0% fuel trim.



300RPM is bad. maybe the EGR is leaking (main valve,) it can be hard to remove, those 2 ,6mm screws. (if off, get the valve to open by hand and snap shut)
I will pull it off and check it out.

the 96 has rubber main intake pipes behind MAF to engine, are they cracked? and boots.
I'm not sure what you mean by this. Do you mean the entire plastic shroud going from air intake to throttle body?

If so, it does not have any cracks.

Thanks again.

[fixkick]

165 or so, and others its 185.
it must start cold, what ever cold is there, now, and warm up and hold a 180 or up to 195 , matching stamp on thermostat ,stock is 180.
if it just keep changing up and down on a hot engine that is bad thermostat or more common, not using the rubber gasket that fits around it.
the rubber missing , there, cause the thermostat to float (and leak)
bad news, for ECU it goes nuts.
good the loop closes. CLose loop and accel. does drop closed loop and fuel goes rich for more power, that is all normal but not that bog.
trim at zero hot engine,, means its most likely, eCu lost controls. of fuel.
what is MAF reading at idle. and then gunned. ( metric or pounds, what ever tool is set to show)
can you see the 02 sensor swing, with that set to live plot, if you have that feature in the tool, it will show the 02 sensor swing fast hot, (about .2v to .9v or so..)


the pipe, is here.
the hose at TB seen here, not leaking, at TB to huge metal pipe, my alum huge pipe had broken mount there, and huge hole in alum huge pipe there.
all hoses must leak air, and and the end of that huge alum .metal pipe are more boots, then you land on the MAF, no leaks to rear of it allowed anywhere.

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the main pipe is full plastic end to end that is 1998 engines, not 1996.
the engine sucks air, and the MAF must read every puff of air.. ,missing not a bit or it will go lean and bog.
http://www.fixkick.com/sensors/92-95MAF/...sting.html

the scan tool will show the above readings.
"The airflow rate should

be 0.20

[Garemie]

MAF at idle is 1.8 grams per second and at 3000RPM it is 7.5 grams per second.

The main pipe on mine is entirely plastic, I realize this is probably a replacement. I will check it for cracks tonight.

I'm not sure how to get fuel pressure, is it possible to read that on an OBD2 reader?

Throttle cable has slack.

I will conduct the ISC hose test tonight as well.

I never knew there was a rubber ring for the thermostat, where do I get one?

[fixkick]

MAF is alive. for sure.
that is not stock. got a photo?

the fuel pressure can be read 2 places on all 16v, at the rail plug, or the fuel filter 6mm banjo port.
the harbor freight gauge has the correct hose. for filter side test, is filter new? if not pressure climbs to 55psi at filter test port and not much to rail.


yes, back in 1992 they started putting in new intakes, with the 4mm lip. (was 1mm)
and added this ring.
all stores sell it but suzuki parts can be wrong. (geo too) do to confusion .
they pub. a TSB just for this calamity
http://www.fixkick.com/buy-parts.html#STAT16

felpro makes it, pn 35432
it's split in the center and wraps the stat edges tight.
http://www.summitracing.com/parts/fel-35432/overview/

lots of places now sell it,

https://www.google.com/webhp?gws_rd=ssl#q=felpro++35432
my 96

http://www.fixkick.com/Cooling-engine/96...mine1w.jpg


hot engine idle is 800 rpm.
if not and way faster , closed the idle bleed screw. gently till it closes, or idle hits 800l.
if that fails. to get 800
pinch the iSC air hose (one is cold 2 are hot) the rpm on normal engine, goes from 800 to 400 or stalls. what is your rpm? at this test.?
if that fails, make sure the throttle valve is not gunked up so bad it blocked open, then put the clay in the IAC intake slot in the TB bore.
if the iAC trick test, works , the IAC is bad, or is not hot, if not hot it will not close, if the water path to the IAC is blocked or not 180f the IAC will malf.
the IAC closes at about 150f. so you need full hot water there or it will stay open and idle will scream. hot.

good luck to you, (we will find it)!

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the stock engine has parts like this on intake.
ID 16 and 20 are known to leak' (when old )

http://www.fixkick.com/fresh-air/92-95-suck1.JPG

stock 96 here (2door geo tracker actual 96)
http://www.fixkick.com/my96-16v/engine2.jpg

page 16 here (true parts list there)
http://www.fixkick.com/engine/96-98%2016...motor1.pdf

[Garemie]

The ISC hose test works, I didn't let it stall, but it probably would've.

The IAC trick - Where do I put the clay? I see two holes on the bottom side of the TB.

I also replaced every vacuum line on the car today just to be certain.

Please let me know about the clay any any other ideas you might have.


I drove it today for a mile or two, and it drove really nice and seemed to idle just a little better than before, but still bad.

Cheers!

[Garemie]

So I did the IAC trick, and it ran fabulously. 800RPM cold and hot. After I took the tape out, the idle got even worse, and I got an code P0505. I cleaned the ISC a week ago, because I guessed it might be a problem. Why does this happen.

I am so tired of this, fixkick. I don't know how you do it.

[fixkick]

the IAC needs hot water, got that? it must have 180F water flowing truth it, to close. it closes near 150F
it has wax pellet inside, just like the engine thermostat, that expands... same way.

the thermostat must hold at 180F, if not the IAC is going to fail.
the thermostat is the first test on all cars and all EFI , for sure.

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it's better than TV, better than , cross word puzzles. or solitaire.

use the scan tool, see ECT, make it happy first. all cars, first.

[fixkick]

btw, nice work !
finding who is messed up fast. very good !@!!!

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the 96 is my fav car.
smart ecu but not too smart. Grin ! like my dang 2008. (immobilizer , Tpms bs, grrrrrrrrrr)