Hello.
I posted a while ago with bucking and jerking and the problem temporarly went away. The thing is when my TPS in plugged in my car bucks and jerks like crazy, but when its unplugged it runs normally.
I replaced the sensor and that was a no fix and I replaced the plug that plugs into the sensor and that was a no fix.
I checked all the wiring everything checks out. (no broken wires or rubbing)
Ideas?
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check for short to ground,short or broken wires
if there is a CEL on, check what it is for. a 02 sensor could cause something like this
running rich? turn the boost up
Engine is a 2200 sfi
CEL is on for the TPS sensor being unpluged and rear 02 heater circuit
all wiring looks good with no breaks or rub marks. all casing is good.
Tunned by Innovative Tuning
yahtzee! rear o2 sensor. replace it
running rich? turn the boost up
Rear O2 sensor does nothing but monitor if the cat is working or not.
I don't even have a rear O2 sensor in my car anymore and it runs fine.
You got an ignition coil going bad. My dads 3800 did the same thing.
- Your not-so-local, untrained, uncertified, backyard mechanic. But my @!#$ runs
yeah im leaning towards a misfire
my car doesnt have a rear O2 and runs fine
Having a '99 LN2 myself, I'd like to see how this goes. So... BUMP!
Go beyond the "bolt-on".
so im thinking ill try unplugging the rear o2 sensor and see what happens ? would that be a good next step i guess? im not gonna just throw money at my car randomly
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Oh and ya it does misfire a lot but only when the tps is plugged in.
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what year is it? new than a 97? If so I'm surprised it even runs with the tps unplugged, the tps determines the fueling in all j-bodies made after 97.
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it is a 1999 and yes it runs just fine with the tps unplugged. still lots of power and everything, just a little less throttle response. the problem is when I plug my tps in I get crazy bucking and jerking.
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Ya now that it has been mentioned that makes no sense. It shouldn't run at all with the tps unplugged, you sure your not unplugging the IAC?
No, I work at a shop therefore I have worked with TPS and IAC before, hence, I am 100% sure I unplugged (and have replaced) the tps. If i unplug my iac my car runs really bad.
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my friends honda element would buck and jerk at 70mph then the computer will shut off the gas until you get to 50mph then comes back on until you hit 70. i replaced the rear o2 and it runs fine again
running rich? turn the boost up
Kyle Matthews wrote:so im thinking ill try unplugging the rear o2 sensor and see what happens ? would that be a good next step i guess? im not gonna just throw money at my car randomly
Well I guess since we cannot actually see the car, randomly throwing suggestions is no help.
- Your not-so-local, untrained, uncertified, backyard mechanic. But my @!#$ runs
i would try o2 because it sounds just like my problem just different times, plus it will get rid of that annoying little light
running rich? turn the boost up
newt wrote:Rear O2 sensor does nothing but monitor if the cat is working or not.
I don't even have a rear O2 sensor in my car anymore and it runs fine.
That has always seemed like a hit and miss thing. Some cars will run completely fine without the sensor even being there. Some cars will throw the engine light on, and some will just run like complete @!#$ without it (or with a bad one). Just depends on the luck of the draw I guess.
newt wrote:Ya now that it has been mentioned that makes no sense. It shouldn't run at all with the tps unplugged, you sure your not unplugging the IAC?
Why would it not run with the TPS unplugged? Once it starts to see engine load and no movement of the TPS it should pop a CEL, and drop down to running in limp mode, sounds like that's what it does.
i find it amusing that SHOoff has nothing better to do but follow me around & be an unhelpful dick in even cross-forum. - Jon Mick
do you got 5volts to the tps
Oedwards wrote:You got an ignition coil going bad. My dads 3800 did the same thing.
one right answer in this thread. . . . . .
TRUST ME. I just fixed my EXACT same issue. and I mean exact same. ran like a bag of @!#$ with TPS plugged in, ran great with it off, changed the coil packs, ICM too just to be safe, brand new from GM off a random donor car at the scrap yard (had many new parts on it, owner probably couldn't find cause of running issue and threw money at it until finally giving up for good) and she runs fine. idles better than she ever has since I've owned it.
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Brad (flatblackfire) wrote:Oedwards wrote:You got an ignition coil going bad. My dads 3800 did the same thing.
one right answer in this thread. . . . . .
TRUST ME. I just fixed my EXACT same issue. and I mean exact same. ran like a bag of @!#$ with TPS plugged in, ran great with it off, changed the coil packs, ICM too just to be safe, brand new from GM off a random donor car at the scrap yard (had many new parts on it, owner probably couldn't find cause of running issue and threw money at it until finally giving up for good) and she runs fine. idles better than she ever has since I've owned it.
It's most likely a coil going bad, could be a faulty spark plug as well, I have ran in to that at work also.
Glad somebody actually listened to me. lol
- Your not-so-local, untrained, uncertified, backyard mechanic. But my @!#$ runs
Changed both of my coils today and it still bucks and jerks with the tps plugged in. I also have new plugs and wires. When I replaced the spark plugs that fixed the problem for 2 days then the bucking and jerking came back.
I'm pretty stumped.
Keep the suggestions coming! And thank you!
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