Hi all

My Saph 4x4 Cosworth was overheating due to sticking thermostat so I'm currently running it without one...

The car now misfires badly as soon as it comes on boost - i'm thinking that this is possibly as a result of the ECU reading a cold engine temp (temp gage is now generally much lower althoug it is in the 'norm' band) and overfueling to compensate...

Is this possible or is it more likely to be something else?

Thermostat is on order so i'll get it in next week just wondered if i have more problems though..

Thanks in advance,
Boon

 

with no stat to coolant temp will drop quite low possibly causing the water temp sensor temp for the ecu which is at the back of the head under the #4 inlet tube to compensate (thinking that the engine is on cold warm up) and allowing more fuel out the injectors,this can also happen if that particular sensor fails,but in your case i would say when the new stat is fitted your problem will be sorted

 

Y ou checked your plug gaps

 

Never ever run a 4x4 without the stat as the bypass channels are open, making the water flow WRONG.

 

dose any one no what temp sensor to put in a 2wd saff cosworth with a 4x4 engine
just mine all ways reads red hot as soon as you turn it on

all help would be good

 

Thanks guys & thanks to all who replied.

After reading Stu's post, I quicky put a new thermostat put back in. Still missfired badly.

So I took out the plugs. The electrode on number 1 was broken off! I replaced the plugs with old ones I had in the garage - it's much better but still wont rev all the way without missing.

I have the following questions if anyone would be kind enough to offer advice it would be much appreciated...

1. Is the fact that the electrode has broke off an indicating of a bigger problem waiting to happen? Lean mixture? (I have pics if there's a way to post them?)

2. What plugs are best and what mileage should I expect? I'm running AB software on Green injectors. Engine done approx 30K - these spark plugs (Motorcraft AGPR 902P) have only lasted about 4k miles - the other 3 look fine.

3. After the engine was built, it was running on Motorcraft Super AGP701C which never missed a beat in 25K miles - I've been told these are motorsport plugs of some kind and are no longer available. Is there a replacement ?

Thanks in advance,
Boon

 

HI,

1ST is where has the electrode gone,(piston?)

2ND, The 902p are good for up to approx 2,bar of boost,

3RD, dont have any info of 701c.
I would check out the fuelling, have the injectors flow checked as may be running
weak on n01, have all checked and conditioned, and the engine checked for vacuum leaks, and boost pressure hold test engine. as may be sucking in air and
weak mixture,

DAVE R.