Low Power After 3000rpm

[swordfish]

have low power problem.ls400 92

full acceleration goes to 3-4000 rpm and then starts to labour-not a miss, just goes dead and wont go past 5000rpm. u back off a bit and it changes up a gear and goes until the same happens again.

have changed:

timing belt, idlers, plugs, leads, rotors, caps, acc. drive belt and bearings,checked timing

again, changed fuel filter, two new cats,air filter looks fine,

scanning shows no codes at all,although air bag light stays on.

any ideas guys?

things not changed: coils. my thoughts were that coils were a go/no go item. am i correct?

[cardona6569]

have low power problem.ls400 92

full acceleration goes to 3-4000 rpm and then starts to labour-not a miss, just goes dead and wont go past 5000rpm. u back off a bit and it changes up a gear and goes until the same happens again.

have changed:

timing belt, idlers, plugs, leads, rotors, caps, acc. drive belt and bearings,checked timing 

again, changed fuel filter, two new cats,air filter looks fine,

scanning shows no codes at all,although air bag light stays on.

any ideas guys?

things not changed: coils. my thoughts were that coils were a go/no go item. am i correct?

←

Hi: Check the engine compression, and transmission if those are normal go to the second answer. Make sure the timing belt is properly aligned and the other parts also. It could be out of timing due to wrong alignment of the parts when assembled. I f you did the work have someone else check it out, and if it was Mechanic X take it to Mechanic Y, in other words have someone else check it out. C

[swordfish]

you will all be glad to know i changed the fuell filter again, and it is much better, still doughy, and misses at 5500. Now have missing at lights in gear with air on especially, it is hot here now-when engine very warm. Will try cleaning t/body next, and tps is apparantly very worn- any ideas on this??

[cardona6569]

you will all be glad to know  i changed the fuell filter again, and it is much better, still doughy, and misses at 5500. Now have missing at lights in gear  with air on especially, it is hot here now-when engine very warm. Will try cleaning t/body next, and tps is apparantly very worn- any ideas on this??

←

Hi Clean the T/Body very good and might need to check the TPS it usually wears out and gives a lot of trouble due to the plastic/metal contact that get worn. The sensor is made out of plastic and the part it connects to in the engine is made out of meta, guess it soft vs hard, the hard always win. If they would made both of the same material they would last much more, but when any of them broke it would be more expensive the replace. www.lexls.com has a tutorial on how to calibrate said sensor, if followed correctly should be no problem.

C

[VBdenny]

Great advice C. Interesting about the two different materials, they must have had some reason for doing so. Once other thing I remeber hearing is that the MAF sensor is easily damaged when being disconnected. You might search for an old thread on this.