New & Stumped

[ShafferMD]

OK -

I just bought a '96 Tracker LSi for CHEAP and was forewarned that it had a "power problem..." The little truck is in good shape and has a history of EGR faults according to the previous owner (a co-worker). It's a 16v engine with 147K on it.

The problem can best be described as such -

It starts fine & idles fair with minor "surge" (+/- ~100 rpm). Revs OK if minor throttle is applied. If WOT is given, there is about a 3 second lapse from idle to 3000 rpm. It is terrible if you take it on the road...it needs about a country mile to get up to speed and if there is a slight grade, forget about it (the good news is that it travels downhill just fine).

I checked the following and I'm now stumped...

- I disconnected the exhaust at the converter to see if it was plugged - no effect (other than being loud).

- I verified all vacuum line routing and all is fine. The vacuum signal is marginal, reading on the gauge just below the normal range (which I attributed to a lower than factory spec idle speed @ ~500 - 600 rpm).

- Checked all plugs and wire visually & gapped plugs, all sems OK.

- Timing is set at 5 BTDC per factory spec



Now here's where it gets interesting...

- Just screwing around, I loosened the distributor and rotated CW and the idle picked up, vacuum signal good on the gauge, and throttle response is WAAY better. Test drive confirms improvement as I can now take the largest hills, but still not "great".

- Checked the timing (shorted check connector) and I am now reading ~12 BTDC.

Though it is not terrible, something is still amiss. If I return the timing back to factory spec, the problem returns and is undriveable...

There were codes set, but I inadvertently erased them without logging them...I know - IDOIOT. I seem to remember IAT, but don't quote me...How long before they reset?

Any ideas???

Thanks in advance...

-ShafferMD

[jtgh]

code P0400 is egr, fail.
see my EGR page , click sig link.

moveing dizzy is not good, keep it stock setting,
you should have checked it to see where it was FIRST, if it was OFF, then that is proof of Timing belt slip, now you erased the proof.

time to check the Cam timing. if you have a bad belt, the engine WILL smash the valves into the top of pistions, can require a whole new engine.
at least all valves bad, and cracked valve guides in the head and pistons beat up.

read my bog page.

Click here >>>>>>>>>>>>>>>>>>>> why-power-loss

This page was generated so you can avoid the bad.

147 k on origional belt is bad news ( I bet it is, hope Im wrong)

Sometimes (many) the bog is a blessing, alerting you that , some one forgot the BELT.
saving the engine, just in time . ( just listen , it IS talking to you)

[jtgh]

key points
power loss, egr closed, no vacuum leaks.
Ignition timing way off.
compression low an all 4 cylinders , eg: 100 PSI , not 150 -190.

dont delay check these and save big $

[ShafferMD]

I did check the timing prior to moving the distributor...roughly at factory spec (ish...the surge makes it bounce a little...) Not to mention, I scribed the original position into the casting so I can always return it should I need to...

I am leaning away from the timing belt...I know what you are saying and I plan on replacing it anyway, just due to the mileage of the vehicle...

After reviewing your bog page...I have some more questions.

Why would the vehicle rev normally 3000-redline, but bog from idle to 3000? Does this point you anywhere?

You mention 'hot-engine power loss'...Temperature seems to have no effect on my problem. Cold, Hot, or Lukewarm, it bogs...Which leads me to another quote of yours:

"If you are having this problem when the engine is cold , the engine is very sick. (most likely a clogged fuel filter or bad fuel pump)"

Why are you pointing me to the timing belt given the abovementioned scenarios? I liked the idea of the propane injection...seems like it would answer some questions...

Thanks for your quick reply...

-MD

[jtgh]

no point, only carefull guessing, this is a practice , we have here..... hahahahah

no actually that is one of the best questions ever here. really!!
hy would the vehicle rev normally 3000-redline, but bog from idle to 3000? Does this point you anywhere?

I guess at vacuum leak ( masked at High RPM due to 2 factors.
1: the leak as a function of total air becomes less ,so AFR get better , thus power.
2: when you really floor it fast, the ECU drops ecomomy and goes to 12.5 :1 AFR
and you will notice more power , even if lean to start. (masking effect)

this is all accidemic as the 96 EFI you can plug in a full scan tool and see all data live.
rent ,barrow , buy.
smart move marking dizzy, your belts ok.

if engine is in perfect shape, tune, belt not slippped a few cogs, given that..
and that is rare here, trust me, we get all the bad cars here.

ok, Lean at low to mid RPM.
bad MAF ( or just needed to be sprayed good with maf cleaner spray)
make sure the cleaner is safe for plastics!
I use CRC maf cleaner. some manifolds are plastic coated inside.

the maf gets coked up, it is a hot wire and will burn anything inducted.
it coats the wire (oil in air is worst and common) and this insulates the wire.
it then reports less air, so car goes lean ( cuz less gas is calc'd as needed)

i am leaning on a leak only because MAP should mess up at all speeds.
but MAP's can fool you .

An EGR VALVE LEAKINg could do that same as you describe.
but idle would be really rough.

The scan tool

it can let you look to see of car is entering closed loop CL, just after OXYgen sensor heaters, and engine gets hot.
you can look at short term fuel trim. it will show lean at low RPMs
you could look at all sensors to see if they are working properly.
ECT, IAT, TPS, OXYsen live data, mAP , timing advance, load, RPM, ALL !

if car has full power above 3k and full power under load cold, fuel pump should be good.
finding leaks can be hard or easy.
just pinch all the vac. lines, listen for RPm CHANGE AT idle,
do not pinch the PCV hose or the IAC/ISC intake hose.
all others pinch. my find parts page shows the hoses.

the hard finds are cracked manifold gaskets, TB gaskets, Injectors bottom gaskets.
many places to leak.
there are tricks to find them.
1: smoke machine. You dont have it.
2: play propane raw gas on places that can leak.

Leak, or MAF.

the Live OBD2 will tell instantly which.

The maf is very expensive and finding dead ones is easy , but finding ones out of calibration impossible to prove. ( I can put a meter on it and see it go to 4v and Id say it is good , when I gun the engine)
but it could be off by 20% on the low end.

id clean maf and pinch hoses.

that is the best i can tell so far.

take Motrin and drink lots of liquids...... and call me in the morning... hooo hooo....

[tracka96]

I'm willing to bet you have the worn crankshaft snout, keyway, and belt drive gear. What you described is identical to the way my 96 was when I got it and it had that problem. Tracka96

[ShafferMD]

JT -

Again you have left me wondering...which is a good thing.

- How much for a scan tool that performs the functions you speak of (live monitoring)?

- How much to have the diagnostics performed at a shop?

- You mentioned full power above 3k *yup, yup* but full power under load cold? I have ZERO power under load, unless > 3000 rpm (cold or hot). Does that still point to fuel pump OK?

Another interesting tid bit I left out...

When attempting to drive during bog (all the time unless dizzy advanced) - I noticed the tranny (automatic) does not want to shift. And when it does, it engages very roughly. I have to rev the crap out of it, drop it into drive and stay on it to get out of my own way (impossible if theres an uphill grade). Then, it hesitates badly when trying to go into 2nd gear.

I know from my previous days, there used to be a vacuum modulator on the tranny that triggered the shift. Is this still the case, or is the shift handled electronically? Just a thought, cuz a vacuum leak would also cause this symptom.

- In a significant vacuum leak situation, wouldn't I rev higher than normal? My idle speed is about 200 rpm LOWER than factory spec. Vacuum leak would make me higher, no? Pinching the hoses would drop the RPM, right?

Thanks again for your patience as I ponder all the input...and continue to ask questions. I am especially grateful for all the help...

Best Regards,

MD

[ShafferMD]

Tracka...

You had the same bog problem? Can you describe your experience a bit more?

Thanks -

MD

[tracka96]

Originally Posted by ShafferMD

Tracka...

You had the same bog problem? Can you describe your experience a bit more?

Thanks -

MD

You have already described my experience pretty much exactly. Tracka96

[jtgh]

the loose crank nut was cured the year of 96 , so this one would have to have been loosened by a service person and not put back to 94 ft/lbs as the spec states.

that should be very rare for 96, and have not seen anyone post a 96 or newer with bad crank snout. (or was I asleep, mostly, LOL)

He said the timing was perfect, and it wont be with a bad snout.
I presume he knows how to do the timing freeze jumper procedure.???

if you suspect it , then just put a torque wrench on it , ( i use beam torsion)
and start turning CW to see where it is NOW.
if it is very close to 90 then it is ok, if it moves below 70 , it was wrong.
and needs inspection.
that is the simplest test I can do. ( visual snot look, is best , of coarse)

i do not know anything about your tranny issue, lock it in 2nd gear and blast down the road, if you have no power , in 2nd , try 1st.
i suppose a bad tranny could suck the life out of the engine, but not below 3k only.

anyone with a scan tool and print out your IDLE log and then a 3000 rpm,
tool costs $60 new , rent $25 , have some one do it, $100 is my guess.
1 hours labor or less if he has a hot engine waiting. and is not a crook.

any time any car , any , runs bad, one must check the basics. ( out of the blue book)
no computer in the world (or sensor) can correct a bad engine.
a tune up skipped, is just a waste of time an money , and gas.

#1
timing, all.
compression.
if you discover Ignition timing off by more than 2 deg. I would get very suspisious.

but really isnt pulling a full OBD2 diagnostic far easier , than pulling the front crank damper? all all below details? right ?

you pull it and look , oh my the MAF is totally nuts, or the Stort term fuel trim shows a massive air leak ( LEAN as HEck) indicates a large neg. offset , yelling , hey dude
I am throwing tons of fuel at this engine and it still comes up lean. WTH

a fuel pump can cause this over 3k easy , so i suspect an air leak or bad maf.

Id kill to have that full scan on my old 91 kicker. ( soon to be, 2 ways)


here you have a smart ECU, do a vulcan mind meld. You are blessed to have it.

really if you are shy of the OBD2 full scan there is no other way in the world to do this
other then measuring all sensors one by one. A long task.


Nothing can replace< i know for absolutely sure
the timings are correct and the the engine pumps air.
compression test takes what 15-30min ?
the ignition takes , 5 mins, (if you know where the Diag freeze jumper is located)
and the cam , is harder.

if the cam is off time, the car will run like crap and soon the engine will in fact lunch its guts. ( belts NEver SLIP ONLY ONE TIME)

i am still trying to figure out if I can pull my cam cover out just enough to see the cam cog wheel outer top edge. if this is possible (with out full dissembly ) this could l be photo graphed, many here are so shy of cam inspections (required every 60-100k) and
if i could find a way to cheat maybe we could make progress with the persons fearing this important inspection.

crank at tdc. , loosen and remove all cam cover screws. just top 5 ,

http://carfix.stufftoread.com/t-belt/cover-1w.jpg

then tilt out the top 1 inch or so, BINGO the MARKS.
when time permits I will test this theory.

another test, electronic, freeze ignition timing, look at marks with strobe light.
if they move, the snot a and key way on crank is gone.
gun engine and the timing must com back each time to 5 or 8 deg. (by year)
and not be off , each gun. do that 10 times.
still at 5 deg? (assumes that is correct)
this would be a half way good , way to test key way.

Keep in mind, pulling the crank bolt , creates the risk of it not wanting to come out
and the risk of stripping it or breaking it, as someone here did, just last week.
so, if you are risk adverse, then by all means , pull the timing cover and inspect
1: timing,
2: belt condition.
3: spin idler , if it spins free and sounds like cheap roller skate wheels , it is bad,if it drags hard and gritty it is in fact bad.
4: water pump, ARE THERE GREEN slime signs? bad.
if this test passes and the bolt dont move and 94ft/lbs , do not remove the bolt.
just pulley comes off. with 8mm screws.

there are many ways to skin a cat ,and each has its own risks, some happen more often, but it is your choice which path to choose.

best of luck
cheers.