Strange cutting out problem! (CDTi 160)

[stephen421]

So over the past couple of months my car has developed a strange problem, I'll explain it as best I can:

When I'm driving on the motorway or a fast road, if I have the car in 4th gear and give it some acceleration to speed up to the 70 mark, the car will make a jolt, followed by a check engine message on the display, then around 5 seconds later, will cut out and I am forced to stop at the side of the road. The car will start again straight away with no hesitation however the check engine screen remains. However turning the car off and leaving it for around a minute will clear the check engine message and the car will drive perfectly normal. I can then drive the car as if nothing happened.

What's weird is the fact that on normal roads this problem never occurs, I can cruise easily in 4th at 30mph with no hesitation or issues. It also only appears to happen when I'm in 4th gear! For example on the motorway if I accelerated up to 50mph in 4th then got to 70mph in 5th the problem does not happen.

Also using the full rev range in 1st 2nd or 3rd (Although I never do this, just did it to see if the issue would raise its head) does not cause any problems.

I can do 500 miles or more without this happening, and then easily another 500 miles once it's happened before I have the problem again.

Does anyone have any ideas?

Many thanks

Steve :)

[Avulon]

Seeing as its not purely revs related but revs and load related I'd suspect one (or more) failing injectors. Have you had it on a T4?

[David Lawrence]

So over the past couple of months my car has developed a strange problem, I'll explain it as best I can:

When I'm driving on the motorway or a fast road, if I have the car in 4th gear and give it some acceleration to speed up to the 70 mark, the car will make a jolt, followed by a check engine message on the display, then around 5 seconds later, will cut out and I am forced to stop at the side of the road. The car will start again straight away with no hesitation however the check engine screen remains. However turning the car off and leaving it for around a minute will clear the check engine message and the car will drive perfectly normal. I can then drive the car as if nothing happened.

What's weird is the fact that on normal roads this problem never occurs, I can cruise easily in 4th at 30mph with no hesitation or issues. It also only appears to happen when I'm in 4th gear! For example on the motorway if I accelerated up to 50mph in 4th then got to 70mph in 5th the problem does not happen.

Also using the full rev range in 1st 2nd or 3rd (Although I never do this, just did it to see if the issue would raise its head) does not cause any problems.

I can do 500 miles or more without this happening, and then easily another 500 miles once it's happened before I have the problem again.

Does anyone have any ideas?

Many thanks

Steve :)

Does it coincide with you having less than a quarter tank of fuel? If so it could be a in tank fuel pump problem.

You should hear the in tank pump by putting your ear to the filler pipe when you first turn the ignition on. It's pretty quiet though so listen well.

In mine 500 miles from a full tank will put me in the last quarter of the tank, could explain why 500 miles between incidents.

[Avulon]

Or a cheaper option (possibly) could be fuel pressure related.

[klarzy]

Does it do this in the wet?
Is you ECU dry with no signs of water damage?
Is your MAF connected and working.?

[stephen421]

Thanks for the replies all.

Definatley not the in tank pump as its done it on a full tank and never has any problem starting.

It has also done it in the dry and my car has the plenum modification. Its dry down there.

Starting to feel it is injector related. Although I haven't had it on a t4 yet and I haven't checked my maf. Although the car does feel healthy to drive under 2k :)

[klarzy]

Thanks for the replies all.

Definatley not the in tank pump as its done it on a full tank and never has any problem starting.

It has also done it in the dry and my car has the plenum modification. Its dry down there.

Starting to feel it is injector related. Although I haven't had it on a t4 yet and I haven't checked my maf. Although the car does feel healthy to drive under 2k :)

I would check the fuel rail pressure sensor and connections then.

[chrishumphries]

I had exactly the same symptoms and it was No2 injector faulty. The seal had split.

[marinabrian]

Stephen, when I T4'd your car last year when Graeme owned it, the MAF was spot on in spec ;)

From the description, I would say you have a badly leaking injector, the symptoms certainly support it.

Time to dig out the old jam jars (or bean tins if you happen to be named Julian) and do a leakback test.

Brian :D

[madone]

I had similar problem last year. Reconditioned injectors solved it.

[stephen421]

Thanks for the replies chaps :) Will look at getting a leak back test done pronto and go from there. I was wondering if a Terraclean would do the injectors any good, as I've been considering having one done, or whether it's worth just replacing/refurbishing the faulty injector(s)

:)

[grivas]

If the leakback test proves a problem with any of injectors you will need to properly refurbish and rebalance the injector/s affected cleaning will not do it.
Good luck.

[chrishumphries]

If your injectors are faulty try Lynx Diesels, they offer a superb service for reconditioing at a very reasonable price.

[marinabrian]

If your injectors are faulty try Lynx Diesels, they offer a superb service for reconditioing at a very reasonable price.

Or a bit closer for the OP, these people are excellent (http://www.thomasfuelinjection.co.uk/)

Brian :D