Help T.D. XJ power loss after 2000RPM

[Drew]

Anyone out there help please. A mate has turbo diesel XJ cherokee that suffers power loss after 2000 rpm , have tried the number one injector, cleaned out fuel lines , checked turbo boost and is ok, changed fuel and air filters, decode computer all ready, and are now at a loss please help any ideas at all, thanks.

[murray]

does it make any noises when this is happening
mine had a hole in intercooler hose tht the previos oner had taped up when the turbo came onto boost it would bleed by this was just before 2000 rpm

[PC_96_GCL_ZJ]

Fuel pump? I just had this prob on my ZG 4.0, problem was heat/time related, gradually lost power at 4000, 3500, 3000, down to 2000 rpm. Particularly quicker loss of power on lower tank. When the tank was dropped was full of crap, replaced fuel pump, filter, blew fuel lines and reconditioned injectors. Now 1500 klm on, puuurrfect.

I never received an error code in my ECU whilst I had this problem. There is no sendor for fuel pressure. Best to hook up a fuel guage and drive with it gaffed to the windscreen if your problem only occurs whilst under load.

[Drew]

the engine pulls strong upto 2000 rpm then it is like the snatch strap pulls tight and it loses power but will still pull to 4000 very slowly, and is flat out at 90kph in top gear , and blows heaps and heaps of black smoke under acceleration. Does it when hot or cold doesn't get any better.

[PC_96_GCL_ZJ]

In the WRX club we usually associate that with a blown turbo, just a thought. The car will usualy continue to drive basically as you describe but blows a space shuttle launching amount of smoke out of the rear end.

If you continue to drive it you will certainly stuff the cat and O2 sensors if you haven't already.

Does is blow the smoke off boost with no load (ie revving stationary)? Smoke usually comes form oil, the turbo most likely has an oil line running through it to lube the bearings and usually a water line to keep it cool, not sure on the Jeep turbo setup though.

Lots of some can also mean running ridiculously rich (my experience on pterol engines only, don't really understand diesels) but you should be able to smell the difference between burning oil and burning fuel.

Better take it to a service centre of some sort and have it looked at (preferably a diesel specialist), if it is the turbo, don't get yours overhauled (usually too expensive and time consuming) get one in from the US or from a wreck.

[mountainman]

Check the exhaust gas recirc valve assembly. Its under the inlet manifold. When i bought my jeep, i found the whole assembly had worked loose, and caused similar symptoms to the ones you describe. What happens is the valve is vacuum controlled to open around 2000 rpm to recirc a bit of exhaust gas so it meets regulations. If it is a loose assembly, pull the whole thing off (not too difficult), buy some exhaust gasket material (not too expensive), make a couple of new gaskets (not too difficult but watch you dont slip and cut your finger nearly to the bone ), give it all a good clean and bung it back on. Then, block off the little vaccum line so the valve doesnt open at all and you should find inproved acceleration and fuel economy.
If thats not it....well buggered if i know
Ian

[Drew]

cool blocked off the egr valve , and took it for a run on the highway and it came good , thanks heaps for all the help and info guys, will just have to see how it goes long term now fingers crossed .

[Grant]

go the the oxygen sensor and either eplace it or clean it

[M3NS0]

21 years later this thread is back...

My name is Edu and I writte from Spain. I hope yo can show me the light...

I´ve a ZJ with the 2.5VM diesel with this issue. I made a service on it, with oil, filters, A/A recharge, oil from groups... and when the car goes out from the service, it didn´t go up 2000rpm on the road. I´ve checked the turbo (it blows until 2000rpm), EGR, checked again the new fuel filter placement, and tryed with 3 differents inyector number 1, and still the same behaviour...

I´ve checked USA forums and the said that the people with more knowledge about this cars and this engine are from AUS, so I´m here asking for help, trying to solve mi problem.

Thanks in advance and sorry to use this thread. Also sorry about my english