Ensoniq5
10-10-2014, 04:51 PM
Hi guys. Searched the forum for clues on this, lots of ideas and few conclusions. This problem didn't exist heading to work in the TJ, suddenly was there coming home.
Under very light acceleration, ie feathered, everything is more or less ok, the engine revs smoothly and gears change normally. If I give it a bit of throttle, the engine just shudders and there's no power. If I hold it in a low gear and let the revs build, I can give it a bit of welly and no problem, though WOT still just shudders. I have replaced the fuel filter, checked no vac in tank, replaced fuel, checked no obvious air leaks in snorkel, no obvious vac leaks, checked operation of EGR and PCV, and eliminated the MAF (still does it with MAF unplugged, though the problem seems to be reduced which I don't really get :nuts:). There's no backfiring, no unexpected smoke from the exhaust, and when it does accelerate ok it does so with gusto.
My best guess at this stage is coil or maybe oxygen sensor but I'm open to other suggestions. The cap and rotor are about 18 months old and I replaced the dist and coil at the same time with a 2nd hand unit (from Mal), oxy sensor could be the original (dunno, I haven'r replaced it). I haven't checked the TPS yet. The front bank plugs will be due for replacement, rear platinums are about 12 months/20k old as are the leads, but I wouldn't think the problem would be so dramatic and so rapid-onset if it was plugs. There's a bit of oil on the leads so I need to do the valve covers and plug seals.
Any other suggestions?
EDIT: Also does it in neutral so not the driveline.
Another EDIT: A bit of reading may have eliminated the oxygen sensor. Seems it only comes into play when the engine's hot, my issue is apparent at all engine temperatures. Considering it is over ten years old and at almost 300k I'll replace it anyway.
Under very light acceleration, ie feathered, everything is more or less ok, the engine revs smoothly and gears change normally. If I give it a bit of throttle, the engine just shudders and there's no power. If I hold it in a low gear and let the revs build, I can give it a bit of welly and no problem, though WOT still just shudders. I have replaced the fuel filter, checked no vac in tank, replaced fuel, checked no obvious air leaks in snorkel, no obvious vac leaks, checked operation of EGR and PCV, and eliminated the MAF (still does it with MAF unplugged, though the problem seems to be reduced which I don't really get :nuts:). There's no backfiring, no unexpected smoke from the exhaust, and when it does accelerate ok it does so with gusto.
My best guess at this stage is coil or maybe oxygen sensor but I'm open to other suggestions. The cap and rotor are about 18 months old and I replaced the dist and coil at the same time with a 2nd hand unit (from Mal), oxy sensor could be the original (dunno, I haven'r replaced it). I haven't checked the TPS yet. The front bank plugs will be due for replacement, rear platinums are about 12 months/20k old as are the leads, but I wouldn't think the problem would be so dramatic and so rapid-onset if it was plugs. There's a bit of oil on the leads so I need to do the valve covers and plug seals.
Any other suggestions?
EDIT: Also does it in neutral so not the driveline.
Another EDIT: A bit of reading may have eliminated the oxygen sensor. Seems it only comes into play when the engine's hot, my issue is apparent at all engine temperatures. Considering it is over ten years old and at almost 300k I'll replace it anyway.