3.5 petrol hesitates at 25-30% load

[jc20b]

Hey,

Has anyone had a experiance with a 01 3.5l hesitating from 1300-1700 rpm up slight hills on 30% load.

I ran evo scan to have a look and its knocking timing back a little in that spot.

SO I used openecu to flash the rpm map retarded a little timing in the spot to see didnt make much differance.

Its got the stock map in in now and just avoiding that spot.

[Aussie_Dan]

There's been a few V6 owners on here over the last few weeks reporting hesitations under load....
How long since your plugs and leads have been changed?
Dan.

[geopaj]

Is it hesitating when you first apply (or add throttle) or is it more of a misfire?

If it's more of a misfire have a look at the thread started by me called "NL miss but only at low rpm, under load, and with approx 20% to 40% throttle" (http://www2.pajeroclub.com.au/forum/...ad.php?t=20119).

I believe the NL and NM-NP had the same 3.5l V6

[Team SPJC]

Hi there, what do you mean by hesitating? my V6 at certain revs seems to slip and revs drop, (like a auto trans slips when belts are loose) but mine is a manual, could these two things be the same or diferent. I am very interested to hear from yon about this.
Cheers

[jc20b]

Thanks will have a look at the post

Its not a slip or anything like that like in an auto trans

Its just flat our miss sounding slighty like a really bad pre igntion but its nearly impossible to be det.

I was thinking igniton coils leads plugs etc though I want to sell the damn thing in the next month so wasnt to keen on spending money. Might have to i guess.

[psproule]

It sounds like the knock sensor picking up pre-ignition at that point. Crap fuel? try some 95 or 98 in it and see what it does. I do know that the 3.5's like to have their ignition system in top nick. Good fresh leads and the right plugs are a must.

[jace]

Sounds like It could be the same issue as Danola http://www2.pajeroclub.com.au/forum/...ad.php?t=20557

I would check the Spark Plug Tube Seals. They tend to fail on the NM 3.5 V6. Once they fail they soak the leads where they join the Rocker Cover and can even send oil down the tube when they are bad. This will definitely cause rough running and misfire.

Checking is fairly simple. You can get at the front driver side Spark plug lead without removing anything significant. Pop it out and have a look for oil around the rubber section that creates the seal to the rocker cover. If there is oil around the lead then you've found your issue. A look into the tube will show how bad this one is.

You should also be able to check the lead closest to the firewall on the driver side without much hassle.

Fixing is a bit of a job but has good results. You need to replace the plug seals, Rocker Cover Gaskets, Leads, and Spark Plugs. If this is your issue check this link for details http://www2.pajeroclub.com.au/forum/...ead.php?t=5357