94' 850 T5 Auto cutting out

[xanadu]

G'day all. Got a recent problem with my T5 engine cutting out. Mostly happens on start up, engine will run and then cut out, feels like fuel but i have not fitted a master gauge to test yet.

Funny thing is though, once it cuts out, if you wait 3 seconds it will start straight up and then may cut out again, and on goes the scenario for 2 or 3 times and then all is good.

All operations are good as in gets full boost, good idle and so on.

One thing i have noticed though is that when this problem exists, the accelerator pedal seems to be harder to push and if you push down to fast it kind of loses resistance and breaks away to the floor????

Today my T5 cut out 6 times or more whilst restarting after getting some milk from the shop. The orange arrow started flashing at times indicating a transmission fault. The engine diagnostic codes are clear (LED light plug type,not OBD type) and i have not carried out a transmission fault code assessment yet.

Hoping someone can shed some light on the subject before going further into it.

Thanks...

[RollingThunder]

I'd check & clean the idle air controller, the throttle body housing and check the adjustment of the throttle position switch as only the idling operation is affected. My bet would be on a dirty throttle body - sounds like the butterfly valve is sticking (hence accelerator pedal sticks) and maybe the bypass jet is blocked too.

Hope this helps.

[Georgey dee]

Have a search for Idle Control Valve cleaning. Sounds like it's sticking closed at Idle which is when it should be fully open.

[pigfight]

Originally Posted by xanadu

G'day all. Got a recent problem with my T5 engine cutting out. Mostly happens on start up, engine will run and then cut out, feels like fuel but i have not fitted a master gauge to test yet.

Funny thing is though, once it cuts out, if you wait 3 seconds it will start straight up and then may cut out again, and on goes the scenario for 2 or 3 times and then all is good.

All operations are good as in gets full boost, good idle and so on.

One thing i have noticed though is that when this problem exists, the accelerator pedal seems to be harder to push and if you push down to fast it kind of loses resistance and breaks away to the floor????

Today my T5 cut out 6 times or more whilst restarting after getting some milk from the shop. The orange arrow started flashing at times indicating a transmission fault. The engine diagnostic codes are clear (LED light plug type,not OBD type) and i have not carried out a transmission fault code assessment yet.

Hoping someone can shed some light on the subject before going further into it.

Thanks...

hi,
i recently had a very similar issue with my 850r (manual though), and it turned out to be a dry joint in my (remapped) ecu!!
after checking and replacing all the usual suspects (fuel relays, fuel filter etc.) i gave up and took it to my local volvo mech, who found it by accident, the car would start and run sweet, but if you just tapped the ecu, it cut out!! so every time i went over a bump it would happen!!
resoldered and sorted now though.
hope this helps, and let us know if/when/how you go on.
regards,
david.

[xanadu]

Thanks for the input. Yesterday i did some further testing.

Engine has spark, fuel pressure, and injector pulse when cutting
out. It does also cut out if you are revving the engine to say 2500Rpm
and has all the above, strikes me wierd.

I did do a full clean on the throttle body and air bypass about a month ago
and thought that it had fixed it, but no...

I have sourced a good running donor car that i am going to systematically try different parts from it to my car, and do some testing on the way, i will let you know how i go.

[xanadu]

Well it seems to have a 213 code / high resistance with the TPS logged in the transmission codes and TPS logged in the A2 codes.

If you clear them they come straight back. I did try clearing them with the engine running and when you do the final 5sec. clear the engine cuts out.

Going to swap TPS from other car today and see how i go.

[bobbych]

Originally Posted by xanadu

Well it seems to have a 213 code / high resistance with the TPS logged in the transmission codes and TPS logged in the A2 codes.

If you clear them they come straight back. I did try clearing them with the engine running and when you do the final 5sec. clear the engine cuts out.

Going to swap TPS from other car today and see how i go.

as far as i know, you should not do diagnostic codes with the engine running, as when clearing, it will reset the CPU, and will cause the car to stall

[xanadu]

Fitted a new TPS and the transmission shift has improved alot and all transmission modes work now.

But the engine still cuts out at times.

It did log a knock sensor code but not sure if that would make the engine stall.


If a crank or cam sensor was faulty, would it have to log a code?

Other than these 2 sensors i am starting to think it may be a fault in the ECU, or

something to do with the knock sensor. I do run premium fuel.

[MrMatt]

Have a similar problem but in a much newer car - V50 T5

Sounds almost identical in terms of it draining away whilst idling although have experienced it cutting out in the fast lane as well as occasionally at lower speeds - seems to be at around 2000 rpm.

Had it in on more than a few occasions and they can never replicate the issue - but it used to give a fuel pressure reading (now no more engine light).

If I hit the pedal to the floor quick enough i can save it but not every time. And besides that ain't so safe... It happened before Xmas. Then fine for months. Fair bit of driving. Then again at Easter.

Fuel consumption isn't great but then that's the car anyway. Have always noticed a slight sense of resistance on the pedal - but might be completely unconnected.

Anyone got any ideas. It's clearly fuel but what? fuel pump? what controls idling? and what controls the gas on an auto when your foot is off the pedal? It's driving me nuts.