97 Tracker, No power off idle. Help?

[Randy M.]

Hey guys, I'm new to the site. I REALLY need some help w/ my mothers 97 Tracker. Here's the problem:

It has no power off idle. It starts and idles fine, and once above 2800rpm's it runs like a scalded dog. With the vehicle in park, if you push down on the throttle very slowly the rpm's will raise, however it takes close to 30 seconds (while feathering the throttle) to reach about 2500 rpms. With the vehicle in drive, it will not pull itself at all. If you stab the throttle either in park or drive, the engine drops to about 800 rpm's and will not rev any higher. I'll list out what I've done to this point.

This is a 1.6 16v mpfi with 141k miles.

At 123K I got a code for the EGR position sensor, replaced it cleared codes and all was fine.

At 125K I replaced the timing belt. I followed the instructions and turned the motor over twice before tighening the tensioner.

At 137K I adjusted the valves and replaced the valve cover gasket.

At around 139k is when the trouble started. There was a small decrease in power at the bottom end. It was time for new exhaust any way and I thought it might have had a clogged convertor, so all new exhaust from manifold back. No change in performance. No check engine lights and no codes.

At 139500 the check engine light came on, I got a TPS code. My mother continued to drive it until I could get the time to pick one up. ( I thought I was going to have a stroke when the dealer told me $319.00us for a TPS) I installed the TPS at 140500. Cleared the code.

No change, actually it is now worse than before. No new codes.

So, I have done the following in the last two weeks and have had no change in the problem.

I checked fuel pressure both at the filter and at the rail. 40psi. I checked to see if the FPR was working by unplugging the vacuum line while running, no change. Still no codes. I disconnected the Coolant temp sensor, tripped a code, no change. cleared code. I installed a used MAF (off of a running tracker) no change. I checked the timing and it is in range and is advancing as it is suppose to be. There are no vacuum leaks. I just installed new spark plugs (the old ones were worn and showed a lean running condition) and a new cap and rotor. I checked the spark, I am getting a blue spark and it will jump approx. a half inch. Where do I go from here? I NEED to get this thing fixed, I have been shuttling my Mom back and forth to work and she has been taking my vehicle in the evenings.


HELP!!!!!!

[jtgh]

very good write UP! wow.
Hello Randy. (are U usa or out of country? , if usa , cal or 48state fed car? )
You are correct it is very lean. ( very sick car)

since you saw codes , is this a OBD2 car, as all 97 should be?
is it the winky blnky CEL , type.?
My guesses:
EGR stuck open (bleeding in tons of exhaust into intake plenum)
ISC = (stuck open ) clean them both .
IAC = stuck open ( but car would idle fast , and this valve will try to compensate for air leaks by closing down (via ecu CONTROL)
MAP = map must compensate for what MAF misses. down stream.
Map can see EGR open and ISC open too much. ( causing compenstation, the ECU has job of setting idle to spec at all times on this gen of car)
how ever the leak may be too bad and too much for it to handle.

Your OXY might be bad but I do not think so. (it only makes tiny changes in trim)

Not knowing if car is OBD2 compliant is a problem.

if it is, we can see if car is going into closed loop and if the fuel trim is all out of wack. OBD2 cars are vastly easier to diagnose, especially ones like yours.

OBD2 conn. is located below steering wheel and has 16 pins.
lower edge of dash.
if it has it , connect a real scan tool one that can see live data stream
if your car doesnt have this let me know.
cheap OBD2 = codes only , nice one has data logs.!
$39 versas $150 ( barrow one from friend)

OBD2:
1996 it was optional ,EPA
1997 is was supposed to be manitory on all USA cars. ( thus my interest)

good day jerry

PS: try my pinch hose test , see my sig link

let me know how u do, I have interest in learning 97's. (fav year)

[Randy M.]

I'm in Ohio. This turd is non-calif equipped. It is an OBDII vehicle.

The scanner I have is not so nice, so at this point I have no way for live data. I just checked the IAC No leaks. i replaced the O2's when I did the exhaust. I'll run out a check the MAP and EGR when the kids go down for nap.

[94box]

i have heard the egr port passage cakes up with carbon, did you check that?

just a thought,

94box.

PS thank you for the detailed write-up

[Randy M.]

Originally Posted by 94box

i have heard the egr port passage cakes up with carbon, did you check that?

just a thought,

94box.

PS thank you for the detailed write-up

Checked that, but thanks for the heads up.

Believe it or not, I used to be an ASE Master Tech, then I got lazy and started working for an Insurance company looking at wrecked cars. The only thing I work on now is my trail truck. (FORD)

[jtgh]

The egr valve , that is stuck open for any reason will cause exactly this problem.
how ever , caking closed is a blessing , in this case , save a silly EGR check engine light. but the car would run like a scalded dog.

You are LEAN !
find out why (lean, too much air, lean to much EGR baypass)

Good !, you have OBD2 , brains in your car. very good.

with a good scanner you can look at
1- when if ever the car goes into closed loop.
2- live OXY readings that are all off the chart LEAN and tons of oxygen.
3- long and short term A/F trims , off the chart.

IMHO every mech should own a full scanner.
I absolutly guarantee the first TIME you use the data log feature, it will pay for itself. ( one hour of dealer shop labor, what the heck )
autoexray, and a ton of others, growing each day.

PS:
thanks for confirming obd2 to me as I am researching if there are 97 that do not have it, ( it is an urban rumor, my guess)
Some out there, claim theirs is NOT.

I just knew you were a pro by your Trouble outline. I can see & feel the strong background. ( dont feel bad I do just the electronics today , day job)
more $

I'd pull the EGR pronto , when kids in bed.

BTW isnt EGR just one big PITA !!! useless tell it breaks and then your hosed. IMHO. (heck even EPA admits it cause more then it cures!)