Calgary Jeep Association
4x4 Related Groups => Tech Talk => Topic started by: yellowjeep101 on May 21, 2012, 07:26:18 PM
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Alright, so I bought a stroker, installed it. Now some problems came up, I'm experincing hesitation followed by backfiring then a surge in power. I ordered a new tps sensor, but if that doesn't work, I'm stumped.
Check engine light is always on no codes. My jeep is a 2000 tj, so it has the coil pack, everything drivetrain is stock minus the stroker engine. Everything ran great before the swap.
So far I've tried a new cps, resetting the system, checking o2 sensors. Hmmmm. Any ideas?
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Backfiring thru the exhaust or intake?
Did the previous owner run a stock ECM programming or custom?
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I've had the same issue numerous times before when the TPS gets wet.
Try it with the new TPS, and if that solves it go to pick and pull and grab a few spares.
Its not fun when your out wheeling and have no power to make it up hills.
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Idont know as of yet, I will hopefully find out about the ecm this week. And I sure hope the tps works, it runs fine sometimes then others it really ducks to drive.
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So the tps was partly to blame, it idles better. But its still having issues with hesitation followed by backfiring, then power again. Time for more research
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Kinda random, did you check for a vacume leak.
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Checked all over, no vacuum leak.
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I'll go out on a whim and say bad camshaft.
Pull valve cover and crank it over to see if the rockers all move same amount.
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Something is wrong with the timing, or feul delivery.
If its intermittent. You may want to check the injectors for a bad one. Does it straighten out when you get into it?
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Yes, when I go full throttle, it works great, and smooths out. The problem is intermittent.
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Did new O2 sensors go in with the new motor? Have you access to a scope that can monitor them while you drive? Any exhaust leaks?
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Same o2 sensors, could they cause the issues I'm having? If so, I'm off to the parts store.
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Could be but without being able to scan them you'd just be throwing parts at the problem.
I'm guessing they are the only sensors that didn't come with the motor?
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The engine came as a block, so my stock intake, exhaust, it came with the thermostat housing with the sensor in that, oh and the cps. Maybe ill take it in and get it scanned to avoid throwing money at it.
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Take it to Jay he said he no's what it is and can fix it for you so your not throwing money at it .
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Thanks, I'm going to see him after work, I love the motor, just the jeep around it is being a B-*** to deal with
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Alright, still not fixed, tried resetting the timing, so I guess that could be crossed off the list of things it may be. But timing is on the right track. Any ideas?
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Did you check for vacuum leaks with quick start/propane or water? What way is the backfire going( intake or exhaust)? So a couple more ideas for you...... Did you change the plugs and wires ( gapped, no bad wires), cap and rotor? Could you have installed a bad one ( even if it's new). Find a set off a good runnin eng and try them. I've had bad plugs before ( new) and wires go bad ( old). Anything plugging the intake making it run rich? (dirty filter)
Not sure because it's stroked, do you have to run a different timing, or deg on the cam? Is that done correct?
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Without a doubt it's the ecu.
Obviously who ever did up the engine would have reprogrammed the ecu to account for a longer stroke of the piston. The ecu is telling the plugs to fire prematurely accounting for the back fire. The longer stroke it takes the more the timing is off from factory. Because our engines don't have distributers, reprogramming the ecu is the ont way to change timing.
Without Brian's ecu you'll have to get yours programmed. Or just go get it from Chanda when they open tomorrow because the longer you run it like that the better chance you'll have of pooching that engine.
Unless what I'm saying has been said already... But change that ecu.
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Checked vacuum and all of the other things on that list, with brake clean and propane, checked timing, replaced tps sensor, spark gaps checked, I'm running low on ideas.
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I could be mistaken, but I swear that engine had a distributor installed last time I saw it.
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Fixed, 02 sensors
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I can honestly say, I didn't see that one. Well good to know anyway
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Fixed, 02 sensors
No F'n way, really??
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Doesn't surprise me one bit. I've seen so many weird symptoms in my (and other people's) Jeeps that are finally resolved once the o2 sensors are replaced.
Thankfully you got it sorted :)
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Maybe a thanks is in order to the guy that fixed it for you ;) I told you it wasn't a ECM.