T4 problems help needed

[Malrider]

Have 96 T4 2.5 Petrol Camper.....thought I had a problem with a plug( drop in power in3rd/4th gear) so I have replaced all pugs, Leads, Coil also sent away and got ECU tested, found MAF Senor fault/repaired ..... after 2 mechanic and $2000 problem still exists...!
Problem is .....Camper starts fine, once you get into 3rd gear and under load there is a loss of power similar to a fuel blockage or faulty pug/lead and at time backfires,
I am thinking that may be Fuel Injectors, or Fuel problems..?

Looking for any Help.....this doing My head in ..!!! posted below thought I would explain better on new thread.

Thanks

 

[WelshGas]

Have 96 T4 2.5 Petrol Camper.....thought I had a problem with a plug( drop in power in3rd/4th gear) so I have replaced all pugs, Leads, Coil also sent away and got ECU tested, found MAF Senor fault/repaired ..... after 2 mechanic and $2000 problem still exists...!
Problem is .....Camper starts fine, once you get into 3rd gear and under load there is a loss of power similar to a fuel blockage or faulty pug/lead and at time backfires,
I am thinking that may be Fuel Injectors, or Fuel problems..?

Looking for any Help.....this doing My head in ..!!! posted below thought I would explain better on new thread.

Thanks

I’m afraid I cannot help you with your problem.. A Petrol T4 is not that common and if the T4 Members on this Forum cannot help it might be worth checking out the T4 Forum. Not so well moderated as this Forum, but some helpful people.

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[TripleBee]

Who tried to repair your vehicle? If it was an official VW dealer, ignore my post.
No offence, but if the one that repaired your vehicle without solution (and it was not a VW dealer), you really might consider to take it to an official VW dealer? They should be able to help you out, otherwise they are not worth their license.

Why is everyone so afraid to go to VW? Sure you will pay too much, but they are obliged to give you a 2 year warranty on every reparation and component they replaced.

If it was VW, ignore this post.

 

[bluerallye]

Who tried to repair your vehicle? If it was an official VW dealer, ignore my post.
No offence, but if the one that repaired your vehicle without solution (and it was not a VW dealer), you really might consider to take it to an official VW dealer? They should be able to help you out, otherwise they are not worth their license.

Why is everyone so afraid to go to VW? Sure you will pay too much, but they are obliged to give you a 2 year warranty on every reparation and component they replaced.

If it was VW, ignore this post.

I have a '93 petrol T4 (AAF) auto and VW Main Dealer (understandably) won't touch it. I have more luck with the local VAG independent specialist but without OBDI/II diagnosis and logging some of the problems are down to old fashioned mechanic’ing….and that’s getting a rare thing nowadays.

Re the OP, I had / have a similar issue but not suffering a loss of power (not that you’d notice on an auto ‘box) but I was getting an intermittent backfire and afterfire but not co-incident with any gear or driving style. I got an occasional ‘check engine’ light also when the engine was under load and in 4th, but rolling off the throttle or cancelling cruise got rid of it. The engine (on 74K) runs extremely clean on emissions, the plugs are relatively new and the colour of the tips is indicating all’s good and there is not a trace of carbon in the tailpipe.

I was puzzled, and still am, but I changed out the exhaust as it was blowing slightly from the cat/centre muffler slip-seal…drawing in oxygen here can cause afterfire. Also on digging around in the engine bay I noted one slightly loose plug lead on the distributor cap which pushed on by about 2-3mm…so whether or not this was the cause of the intermittent afterfire I don’t know but it hasn’t come back since. As you seem to have changed all this out then I doubt this is your cause but you didn’t mention distributor?

Good luck finding whatever it is and please post back here if you do get to the bottom of it.