Hi I need help please.

I have a 4x4 cosworth engine.
The car runs fine all through the rev range with medium throttle.
When on full throttle and full boost, when the car reaches about 6500 revs the engine will cut out and will not respond at all - the ignition lights do not light up.
When the engine drops below appx 2500 revs the engine will then respond but will not go above 3000 revs without cutting out again.
At this point when the car is stationary when a steady half throttle is applied the engine will rev up and down from normal idle to 3000 revs. up, down, up ,down etc.
If the engine is then turned off for about 5 mins everything returns to normal until giving it full throttle again.

P.S it is not Limp Home Mode.

Any ideas will bit greatly appreciated.

Cheers Pete

 

I'd get a fuelling check done asap, if not sooner, after a pump rewire and fuel filter change.
I'd also avoid at all costs giving it death until the check as a very minimum has been done.
tabetha

 

Thanks for your reply Tabetha.

Bit of an update, the car is running fine now but after some rectification work.

1) I found both the loom plugs wet and full of green shit.

2) I found that the fault only occured on max throttle only. (Any revs)

The loom plugs have been cleaned thoroughly with electrical contact cleaner.

I have disconneccted the TPS and now the car runs brilliantly.

My questions are now -

What function does the TPS serve and is it safe to run the car with it disconnected?

Regards

Pete

 

The TPS (Throttle Position Sensor) informs the ECU of the throttle angle and from this info engine load can be determined. One example is shutting off fuel on the overrun if the throttle is closed and so better economy as a result. It does obviously need the sensor I am surprised to hear you say it runs 'brilliantly' does it not hesitate at all or anything?

Martin

 

Thanks for your reply Marty.

Update number 2 - After removing the TPS sensor the car fine until the engine become hot then it would not go over 4000 revs so the TPS sensor was reconnected.

Now I'm back to square one with the car cutting out at max throttle only.

I couldn't understand why the car started to do this but I have found out why now.

Originally the car would never achieve max throttle because the accelerator cable had been adjusted so that it only operated the throttle houseing arm to 95% of its movement hence why max throttle had never been possible. (By others?)

When I serviced the car I had adjusted the throttle cable correctly so that throttle houseing arm would now travel 100% of it movement and would now acheive max throttle.
This is when the problems started!

I have now wound the accelerator cable back so that the throttle houseing arm only just does not reach max movement and the car drives fine and strong just like it used to.

Now I have to find out what is causing the engine to cut out at 100% throttle movement?

Has anyone had this problem before?

Regards Pete.

 

might need the tps resetting, you have to loosen bolts and rotate so you just start to feel spring resistance...thats it as far as i remember.must do it it on a car i have here next week tho.

 

i had a similar problem with my 4x4 saph, it was the 2 engine loom multiplugs on the bulkhead by rocker cover. chopped these out and soldered now fts fine