Another Throttle pots/ Adaptives set up issue

[Wolvesboy]

Hi All,
Sorry about the long post - getting really p****d off now with the whole set up and CONSTANT adjustment of the adaptives etc along with poor chugging/ running under load. Had a nagging misfire as the car warms up for ages now (new plugs/ leads less than 2k miles ago, new coil packs, new big fuse, new battery, today new TPs) and the misfire is still there.
2 weeks ago with the old TPs, I reset the whole throttle body (idle screw off, TPs to 16.9ish, adjust linkage so both the same, adjust idle etc etc) as I had oily/ petrol deposits on the rear of the car body and on the bottom of the doors. I cleaned the air temp. sensor and my earth seemed ok when moved previously. Lambdas seem ok and have not been touched.

Ran better for a few days on short runs but now the misfire is back again with all of the settings out (adaptives etc). Having been on a short run it was misfiring terribly under any load. I go to adjust the adaptives again and they are all over the place. In fact the odd side range of adjustment will not even go past "zero." The even bank is not as bad - the adaptive bounces around from -16 to +8 with no chance of getting it anywhere near the golden zero. When I adjusted them both 2 weeks ago I got close at +0.4 to -2 which I was happy with. No chance now even having changed the TPs for the new ones bought from the thread about 2 weeks or so ago.

Why do the settings keep changing?
Why are the adaptives bouncing around?
Any ideas with the misfire?
I'm seriously considering selling up and moving on - someone please convince me otherwise.

[ginkent]

I’d try these 3 things in order:
1) check for air leak around manifolds, they can throw out the lambdas
2) change the lambdas
3) drop it off at Jules, he will find the problem, correct any mapping issues and likely find some missing horses too

[ukkid35]

Also worth checking for

Faulty Fuel Injector

Cracked Exhaust Manifold

[Jhonno]

4.2 or 4.5?

How old are the lambdas? When where they last changed?

Have you changed the fuel filter recently?

[Wolvesboy]

Thanks for the info.... gone in to get decatted along with manifolds and air intake "smoke tested." I reckon there are a few leaks throwing the AFR off.

Fingers crossed.

[pmessling]

Worth checking the plugs on the coil packs. Might find a pin pushed back or a wire coming out.

Leak around the throttle body heat barriers is another. Which I experienced, all new o rings made it run loads better after a set up.

[Wolvesboy]

Sorry - injector “O” rings?
I’ve checked and checked the coils/ht leads/ ht connections. Checked for a spark from each plug on turn over (took ages). Checked lead to plug with one boot being split - changed with no difference.
Using EvoOllies program my throttle and adaptives were all over the place as mentioned previously - I could not get a static reading unless the engine was off (then cannot do adaptives).
I cannot wait to see what the smoke tests reveal and hopefully somethings come up or are e
Imitated at least.
Getting a bit sick of it to be honest - 3 other cars and never any issues at all. Always the Cerb needing attention and it is driven the least by far. I’m starting to hanker over a Sierra Cosworth I’ve spotted for sale as the YB cannot be any worse can it?

[gruffalo]

Wolvesboy said:

Always the Cerb needing attention and it is driven the least by far.

I think you have just pointed straight at the issue, Cerbs need to be used.

In some years during my ownership I have done low mileage and ended up with running issues, other years like this one I have used the Cerb regularly covering some 6K so far since April and she hasn't missed a beat.

You could try just using it, that is what I have done in the past when she has been left too long and started playing up, drive through the poor running and once everything gets properly warmed through several long heat cycles the gremlins magically clear up.

[Wolvesboy]

I was of the same opinion about driving the car as much as possible.
However, just driving it in this instance is not going to cure the issue. I’ve just spent the last 20 minutes adding up all of the maintenance things I have done over the last 33 months of ownership and it is a poor indication of the perceived “drive it” notion. I won’t bore you with that information but I was shocked myself at how many actual things I had done to this car to keep her on the road.
No wonder the wife calls her the “other woman!”

[Wolvesboy]

Ok - my manifolds leak like a “sieve.” Quote from the exhaust place! All vacuum pipes are good
No wonder my AFR values were all over the place!
Now where can I get some manifolds as I’m not in the position at the mo to get the expensive ACT ones?

[ginkent]

Have you tried the usual places: tvr-parts etc ?

[Jhonno]

4.2 or 4.5?

[pmessling]

Any second hand ones will probably leak like yours. Might be easier to remove them and weld the cracks. Unfortunately they all do it. I've welded mine up but I suspect mine have cracks again from the smell of things.