Thanks @nige8021 I’ve tested the TPS and afm so far all values are the same as on the autodata. I’m just warming up the air temp sensor in the afm as that’s my last test - it is 2 degrees here and it needs to be tested at 20! 

On 17/12/2020 at 19:37, Bawbag said:

It’s bogging in neutral most noticeable at idle when pulling away for example and even when pushing throttle at cruising speed it hesitates. As soon as I switch the engine off and back on it goes away instantly, idle speed is back to 950 rpm and the whole thing has gone and engine performance is bang on.

 

With it doing this it could be earth related, or fuel pump relay (also new from Max RPM) or something else over fuelling related?

 

I have cleaned up the earths on the inlet and the new lamda obviously had a new earth. Run a separate earth from the lambda plug directly (like spliced in?) to the negative or from the inlet earth mounting point?

 

Timing shouldn’t have changed much at all, was set up as per that post a about 5 years ago. Worth doing again?

 

Always worth doing on a GT in my opinion. Did you try the jump lead between the inlet and battery negative? Quickest, crudest diagnostic ever, but it can tell you a lot.

2 hours ago, Yeti said:

Always worth doing on a GT in my opinion. Did you try the jump lead between the inlet and battery negative? Quickest, crudest diagnostic ever, but it can tell you a lot.

Worth re doing the timing? I’ve already got a thick earth going from inlet to bulkhead / body.

Edited 30 December, 20205 yr by Bawbag

Okay update from a productive day; 

 

Tested the AFM, TPS and coolant temp sensors against the autodata that Nige has posted, great help thankyou!

 

I used a bit of wire and hooked the threads between the relevant pin of each sensor and the plug, rather than backprobing, far more reliable and easier to do!

 

All the values that came back were very close or the same except the AFM intake air temp at 20C and the coolant temp sensor at 20C, both read slightly off the values on the autodata. Especially as they got colder, I monitored engine temp  using a handheld laser temperature gauge. I can give more specifics if people want to know. So given the symptoms of the problem when it is cold started and overfuelling, I swapped out the AFM for a spare and replaced the temp sensor. 

 

Next step is to see how this makes the engine behave, if still the same then I’m planning to swap out the ECU. Just wanted to understand what the sensors were seeing and sending first.

 

I’ll keep you posted, thanks for the links and help, much appreciated!

Edited 30 December, 20205 yr by Bawbag