Any ideas?

[thesaint]

Hi,

Timing belt recently went on my car, so had it in to get repairs, radiator was in bad nick too so got that replaced, a new water pump, i think 4 valves in the engine and the belts and tensioner done. When it was done, from cold the acceleration would be very intermittant, car was very jumpy, at times you could also floor the accelerator pedal and get nothing. This problem appeared to ease after about 15min driving. I brought it back to the mechanic and he brought it to a guy who had the equipment to read the diagnostics, he suggested replacing the throttle body housing. So bought that, and it has now been fitted. Problem still remains! Sometimes if you try to floor it the exhaust system warning light comes on, but it doesn't sound like there is anything wrong with the exhaust? I have spent over 2k on it now and it is still not drivable. Does anyone have any suggestions on what the cause of the problem could be?

[CJ]

I brought it back to the mechanic and he brought it to a guy who had the equipment to read the diagnostics, he suggested replacing the throttle body housing

I would love to know what errors were generated that lead him to the conclusion that the throttle body was defective. Suggest you undertake your own diagnostics, its an easy process, see here

It has to be something simple, a diasgnotic check should offer up some sort of idea. Water pump, belts and tensioners being changed is routine but whats the story with valves being replaced?! Did the mechanic say why this needed to be done. Your specified location doesn't offer up any ideas where you're based , if you're in or around Dublin, get it over to Paul Nolan in Artane if all else fails.

CJ

[Mustang]

but whats the story with valves being replaced?! Did the mechanic say why this needed to be done.
CJ

If the timing belt has snapped, then it's possible for piston to meet valve, damaging valve. Unless of course it's a non-interference engine?

[CJ]

If the timing belt has snapped, then it's possible for piston to meet valve, damaging valve. Unless of course it's a non-interference engine?

It makes sense when you actually read the first line properly, my brain changed 'went' into 'changed' for some reason

CJ

[thesaint]

I have tried to read the error codes but none came up. Maybe I wasn't doing it right.

I'm in Leixlip, Co.Kildare by the way.

[steelroe]

The 6A12 engine is an "interference engine and there is a warning in the manual when changing the timing belt that the inlet and exhaust valves can touch (interfere) with each other.

If the belt snapped I am surprised that more damage was not done.
Couple of questions

1. was the car running OK before the the belt snapped?
2. Is it possible that the timing is not correct after the new belt was fitted?
Could the exhaust/cat be blocked.
I doubt if the trottle body has anything to do with your problem.
When you say you get a warning light is it the red exhaust warning light or the orange engine fault light.
How long was the car out of action, the Idle speed control ISC could be stuck or knackered, worht checking.

One thing I always say is never let anyone adjust the throttle body settings unless they are absolutely sure it is at fault as it can screw things up.

ISC first port of call.

A secondhand engine would definetely have been the way to go. Half the price!!

[thesaint]

Thanks for the suggestions.

Rory, to answer your questions:

1. the car was running fine before the belt went.
2. timing is fine, car improves after around 15 mins, if the timing was off I don't think this would happen.
3. Again, if the exhaust/cat was blocked I don't think the problem would improve as the engine warmed up
4. The warning light is the exhaust system light (bottom left)
5. Car was out of action for about 2 months.

If the idle speed control was the problem would that affect the car while driving?

[steelroe]

isc will effect the car while running. Does the car cut out a lot when cold.
I would take out the ISC and clean it and see if that has any effect.

[kevinod]

Strange it happens when the car is cold and not when its warm... hmmm thermostat, or maybe a temperature sensor maybe?

Have you tried resetting the ECU, i.e. disconnecting the battery for a while? although presumably the battery would have been disconnected when doing the timing belt...

What oil did they put in it? not sure if it would cause that kind of problem, but when colder the oil would be thicker, and if it was the wrong oil maybe its thicker than the engine would like. Then when it was warm it would be less viscous (sp?).

The exhaust light coming on is a bit strange, have a look at the troubleshooting parts of the workshop manual to see if there is anything about it there.

[CJ]

Strange it happens when the car is cold and not when its warm... hmmm thermostat, or maybe a temperature sensor maybe?

You would imagine that a diagnostic check would reveal something about dodgy sensors, thats the strange part.

The exhaust light coming on is a bit strange, have a look at the troubleshooting parts of the workshop manual to see if there is anything about it there.

This points to possible problems with the lambda/oxygen sensor, again, a diagnostic should show this up.

CJ

[kevinod]

You'd think it would alright, just 'brain dumping' what kind of things that might be wrong... diagnostic should pick up on those alright.