Hi all, my stock 4 door 98 sidekick (1.6, 4spd auto, 93,000 miles) is running like a dog. Low end power is way down. It isn't throwing any codes, just very gutless. It does not backfire, it does bog a bit. Plugs were replaced and throttle body was cleaned probably 5000 miles ago. It has a new air cleaner as of today.

Any suggestions? At 93,000 I figure it could use an o2 sensor. Perhaps someone on here has had a similar problem before I go replacing parts..

Thanks

Slipped cam timing belt
Low fuel pressure or plugged filter

I'll start with the fuel filter/pressure first. I doubt it skipped a tooth on the timing belt. I replaced it last year. I imagine it is possible though. I guess I could verify that by putting it on TDC and checking where the distributor points.

Thanks

Loose crank pulley?
When you replaced the timing belt, you didn't take the big bolt out of the center of the crank pulley, did you?

Hmmm, no response to that last question has me wondering.

Hmmm, no response to that last question has me wondering.

He hasn't been back on since the 9th (which was before I posted it).

Sorry for taking so long to reply. Had family visiting.

I was able to change the fuel filter--no difference. Still have not had time to check pressure.

I doubt it is the timing belt as it runs well at times. If it was off a tooth, I would suppose it would be consistent.

It was a year ago when I replaced the T-belt.  Don't remember if I removed the big bolt or not.  I am sure I would have tightened it if I did.  Will have to double check for good measure though.

Check the keyway on the pulley.. see if it's wearing. When mine work it did this for a while then work enough that it just ran crappy all the time.

Zig

I really doubt that it is the keyway. From my experience with Mitsubishi 3.0 motors, I know to always be very careful about inspecting the crank end, key way and pulley on anything with a T-belt.  To boot, I always make sure that I tighten the snot out of the bolt.

I don't recall anything abnormal.

In addition, I would expect it to consistently 100% of the time run poorly if it was a tooth off. As it is now, it actually ran great this morning.

When I get time, I think I will check the fuel pressure.  What should it be on a FI zuke?  50psi?

Thanks

So have you checked the timing?  If not, I would check it.  If so, what was it set at?
Fuel pressure is 30 something up to low 40s, depending on the year....I don't have the chart in front of me right now.
You are right, if it was a tooth off, it would run crappy all the time.  On the other hand, if the crank pulley is loose, it would run crappy sometimes and good at other times....depending on the position of the crank pulley in relation to the crank.

It was a year ago when I replaced the T-belt.  Don't remember if I removed the big bolt or not.  I am sure I would have tightened it if I did.  Will have to double check for good measure though.

I would think you would remember if you removed it.  They are usually a PITA to get broke loose.

Did you get it figured out? Mine is doing something similar. Good luck!
Thanks,
Kjmac

Ok,

I got around to checking the ignition timing.  It is at 5 degress BTDC, which is what it calls for under the hood. According the the Haynes book, you just connect the light, point and shoot.  Under the hood it instructed me to inspect the timing with the "check connector short circuited." What and where is that?

I checked the throttle position sensor and it appears dodgy when I check the resistance between terminals B and D when throttle is in closed position. According to my Haynes guide, it should be anywhere from 0.3 to 2k ohms. I am getting a reading of like 4k.

I believe I have the sensor adjusted properly, but who really knows as it is terribly difficult to get a feeler gauge b/tw the throttle stop screw and throttle lever.  I will definitely take the throttle body off the car and adjust it on the bench before forking out $225 for a TPS!

According to my Haynes manual, it should throw a code P0122 or P0123 if the sensor is bad.  Mine is not setting any codes. Who

Mine checked good and so did the extra one off the bad engine and no code. The grounding of the connector is in front of the battery with a rubber cover. My haynes doesn't show the right plug. Is yours sputtering and missing at certain rpm? I had to unplug my TPS to get it to run decent!

KJ,

For the most part, it intermittently bogs when accelerating.  Mid/top end power is not so bad. On occasion, if I am in 3rd or 4th gear at about 2000 RPM it will spit and sputter, but not in a terribly noisy way.