Hello there guys!
I got some problems whit my Cosworth that I can't sort out, so Iam hopeing that someone here can help me out! My problems is, that the car runs bad when Iam revving up the car to about 2000rpm, it drops down, and then revvs up again, over and over, even if i got the throttle even. Same thing happens at higer rpm too.
And this is when Iam standing still whit the car on idle. After many hours whitout finding out why this is happeing I tried to change the chip to an aftermarket tuned chip whit larger injectors etc, whitout oxygen sensor regulation in the chip. And the car runs great! So i tought it was the standard chip or the standard injectors that was causing the problem, so i orderd a new regulated chip whit the 803 injectors and was pretty sure that would help, but not. Same problem appeard whit the revvs. I tried to unplugg the oxygen sensor but no luck. Still the same! I feel that there is someting whit the emission stuff that are the problem, but i don't know what. So any tips would be lovely and be patient whit my english

// Best regards, Linus from Sweden!

 

Have you cleaned the idle speed control valve?

After its warmed up try unplugging it and see if that helps,if it does then clean with petrol

 

I've tried that already, same thing happens

 

Coolant temperature sensor maybe?I had similar years back and new sensor cured it,it's the blue sensor on back of head inlet side,just replaced mine,different problem I have tho

 

TPS set correctly?

 

Hi,

its a mysterious ...have this kind of problems with cossie. I had it too... and today my idle on cold engine is jumping from 700 do 1100 rpm again again and again.

I had your problem too...last year. First, is car running correctly? Under full thortle? ( fuel pressure).

This can be a TPS, ECT or MAP. Lambda has nothing to do with this. In this old engine..lambda is not very important for ECU.

Open the web www.bigturbo.co.uk and find table for ECT and check if you have proper value on hot engine from sensor. Same value is from IAT sensor!

You have to check your MAP sensor.... the best thing is try to change it for test. Or you can measure the voltage comming from map sensor on idle! You find values on bigturbo website.

Next, check your vacuum system for leaks. Pipe to the map sensor, pipe to blow off, breather system, pressure regulator.... Is your TURBO gauge on -0,6 on idle?

You can try to adjust the idle....warm up the car (half of temperature gauge). unplug the ISCV (idle control valve) and set the basic idle with screw under the valve at 900-1000rpm (better with your head lights on).

After this...... tell me your result ..or you can send me PM or skype. But dont remember that cossie is neverending story

 

For a start I would question why you have that software/injectors, with your spec?

It will be calibrated for a 3 Bar MAP sensor, you will have the standard, so this is wrong to start with!

It's also strange that you had a calibration without CL, as the P8 has no way of adjusting the CO.

This will cause all sorts of problems, one being it will not pass the emissions test (Assuming the regulations are the same as they are here there!).

I would start by making sure you have the correct hardware (such as I mentioned above) and then get it setup, as it stands you risk a meltdown!

The base idle should be set with all electrical equipment switched off!

Martin

 

Had virtually the same problem, was the map sensor, bought a new 3 bar and it was perfect !!

 

I found them, thanks! This is great work, and will save me a lot of effort.