so yesterday afternoon, I felt a bit of "bucking" in first gear, as if I wasn't giving it enough gas. it did this a few other times that afternoon along my 30-mile drive, in other gears as well. also, it was idling very low for a bit and the check engine light came on, briefly.
it got me thinking (because I'm a worst-case scenario kind of guy) about the timing chain and how I'm the 4th owner of this truck (206,000 miles) and I don't know if the chain has ever been serviced.
I know this sort of behavior is typical of low fuel pressure or an air/vac problem, but is this also the type of behavior that could indicate a chain that's about to fail?
I called my mechanic and asked when timing chains should be serviced and he said "when they start making noise." I don't think mine makes any noise. Sometimes right when the truck starts and does it's initial revving, there's something of a scraping sound but nothing major (may be normal, I don't know).
Anyway, should I change this chain purely for maintainance, or do ya'll actually wait for a warning?
I should mention: '96, 2wd, 4cyl
Thanks!
Last edited by NelsonCnty : Mar 13th, 2008 at 07:29 AM.
...bit of a debate on when/if the timing chain should be changed. If you do a search on it, you can read both sides of it. The earlier models had plastic cam chain guides, but u'rs should have metal guides, and should not need changing. Either way I don't think u'r symptoms have anything to do with the timing chain. This should be an easy diagnosis since the check engine light came on. Go to u'r local autoparts store and have them read the codes. Could be O2 sensor which is a common problem. Anyway, get the code read, and report back...
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1995 KA24E
Odometer quit working at 124K
yeah, I read some of that healthy debate here about that
the check engine light came on only briefly. am I correct to assume that this code is still stored in the box? if so, I'll pop the seat out and read it tonight.
the book says that the throttle sensor circuit is open or shorted and this fix must be performed by a dealer or shop. is this really the case? what can I look at here?
this bucking happened again yesterday afternoon. seems to happen after it has warmed up outside.
I wouldn't worry about the timing chain. I hit a deer with my '93 when it had 220k miles on it. Since I had the radiator out and the hood off, I decided to do the timing chain. It was fine! I replaced it anyway, since I was already in there, but everything looked good.
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Paint/Controls Engineer by trade
MV enthusiast by choice!
1993 HB 2.4, 280K miles
1988 Suzuki Samurai 1.3
1967 M35A2 (Deuce and a half) multifuel.
Kubota Forklift with Nissan engine
the problem seems to have subsided lately. I noticed a few days ago when I went to fill up on gas that the cap was loose. we also had a couple of rainy days...so I'm thinking maybe some water or air got in the system. I put some gas treatment in with the next fill up and made sure the cap was on correctly (duh). hopefully, this does the trick.
My truck bucks in all gears when I coast. I left off the pedal, it coasts a little then bucks down. When I hit the gas again it buck back up. It's like there is some sort of threshold. I can make it do it every time.
Not absolutely certain, but most FI engines use a Throttle Position Sensor. This is a variable potentiometer on the accelerator pedal that gives different resistance as the throttle is opened up. There is actually no mechanical connection to the FI unit, just electrical signals.
So, call a dealer and see what one costs. It may be reasonable. You may want to hit a U-Pull-It yard and get one cheap.
__________________
Paint/Controls Engineer by trade
MV enthusiast by choice!
1993 HB 2.4, 280K miles
1988 Suzuki Samurai 1.3
1967 M35A2 (Deuce and a half) multifuel.
Kubota Forklift with Nissan engine
Changed my fuel filter last night and gravy came out, bucking seems to be gone. Its not to hard, just take off the air cleaner housing and be sure and use a puralator brand
I still have the problem but I'll share some narrowed down symptoms.
First, it only starts "bucking" after the engine has reached it highest operating temp.
Second, I have found I can make it go away for a while by pushing in the clutch and rev the engine to about 5000 rpm. I'm not sure this is a good thing but it's what I know works for now.
I keep thinking it might be a vacuum leak but I can't find anything. Do gas caps go bad an cause problems. I bought a replacement about 6 years ago that locks with a key.
Linear Mode
