Hi,

Some advice if anyone has come across this?

2wd Cosworth in a mark one shell. Runs lovely but when driving between 1750-2000 revs it seams to loose power, revs drop the whole car jerks before running done again. Does this every 10-15 seconds between these revs? Anyone any ideas?

I have put on some Bosch grey injectors and a different chip but it hasn't changed.

 

Check the TPS output.

However the main concern is where you say you have changed components, you can't just simply fit a chip and fit different injectors, which leads me to question whether the current calibration you have is correct?

Martin

 

Cheers Martin,

I've never tuned anything before so bear with me. I'll do some digging on the TPS and how to check it.

I brought the car running dark green injectors the lad had a bag of injectors and chips and says when he brought it it was running the greys and this other chip which says on it something like custom 7.1.1.

After doing some digging I presumed this is a customs mapped chip so gave it a whirl. It def has more power. It was over fuelling before and still is now. Any advice re what else I should be changing is welcomed.

 

Maybe should have mentioned it's running a T34 turbo 3 bar map sensor and WRC head gasket. It's not just a standard engine.

 

2WD is open circuit with the throttle closed, and it should decrease from circa 5V in proportion the further the throttle is opened to around 0.5V @ WOT.

Having read your last post don't even bother checking this, as you have more serious issues!

The custom 7.1.1 sounds like the compression ratio, that would be a for a low compression engine (which yours may not be) in which case serious damage will result, in addition to it running badly!

You need to be sure that the calibration you have matches your engine entirely, examples are turbocharger, CR, cams, injectors to name just a few.

MSD's chips for example can be verified by S/N.

Alternatively, they have basic specs written on them, in your case the CR which doesn't really tell you anything, so unless you have the means to examine the maps and know what your looking for there is no way of telling.

The best advise I would give is to get a RR session performed by a reputable tuner and drive it very gently until this point!

Martin

 

I have intended to get it on a rolling road and set up but I want to make sure it's some who knows what there doing without having to travel to far. Only had it 5 days so not found anyone yet.

It sounds like I may be best to put it back to what it has been running for last 8yrs and get it in ASAP.

Cheers for the advice.

 

Correct put it back as it was and take it to a tuner a cossie tuner would be best as most have not got a clue. it will cost you a lot more money if you don't get it sorted by a pro ie engine rebuild.

regards

Paul

 

Don't mess around, get it sorted properly by a reputable tuner, you've got Collins up the road from you so go there. Or MSD