4.2 running rich, advice needed

[pat_y]

Chaps, i have recently noticed my '97 4.2 is running a bit rich, strong smell of fumes from the car very noticable when the car is cold, but you can still smell this when at normal running temp as well.
It also seems to be drinking fuel a bit faster than normal.
I plugged in the diagnostic software a couple of weeks ago and found, both tpots exactly matched at 18.5, no spiking at idle position or part throttle when running or engine off.
Lambda signals seem to be fluctuating from 0 - 1.2 randomly from both sides as far as i can tell as the graph is quite hard to read.
Adaptives are zero on adaptive 2 but +10 on adaptive 1. This does not really change much as i rev the engine a bit.
I tried resetting the adaptives as i have recently fitted one of Joo's cooling chips, sure enough, adaptives go to both zero, but they are back to +10 on adaptive 1 within 10 seconds or so.
It has also starting kangarooing/stuttering in traffic using very gentle throttle.
Also noticed over the last hundered miles or so the idle speed has increased by 100 - 200 rpm to around 1200 on tickover when warm.
On the plus side when you prod the angry pedal i still get pops and bangs and scud missile launch performance.
As this has happened only over a hundered miles or so i'm suspecting i might have a dodgy lambda sensor rather than adjustment of throttle pots required.
Would appreciate some guidance from those who have seen these things in the past,anyone know what's going on here?

[Steve_T]

Lambda values should scroll, not stay steady as the ECU is constantly tweaking the mix. Your idle speed sounds a bit high, but not massively so and I've found the reading on the dash is higher than what the ECU software reports. If you have one of Julian's chips installed, the best person to tell you how to setup your throttles for it would be him.

When I have hesitancy on my car it tends to be play in the throttle linkage that causes it, plug in a laptop to the ECU and watch throttle %values for the very first part of throttle travel. If the % on one side moves and then the other, then the movement of the throttles not being in step is what's causing your problem (the ECU is looking at different sites in the map for each bank).

[spitfire4v8]

The cooling chips have exactly the same ignition and fuel values in as every other chip, so no special set-ups required. You don't need to reset the adaptives, in fact youre better if you dont as it's only got to relearn all that info again.
a lambda 1 mix will slow a tickover down from where it would be on a slightly richer mix, so anything that richens it up is going to increase the idle speed (like dodgy lambda sensors).. but also traditional tickover-raisers like air leaks will have the same effect, as will any changes in the throttle positioning eg throttle stop and link rod changes/movement.

[pat_y]

Thanks guys, just to clarify, i believe this issue was possibly present before i fitted the new chip. It might just be becoming more noticable now.
I notice in the help files of the diagnostic software that a failed throttle pot causes the ecu to read the second throttle pot only, i suspect this would cause the ECU to change adaptives on the failed bank to suit. As i have throttle pots reading exactly the same, could this be my problem?
I don't have a MIL light constantly on though.

[Steve_T]

Replace the failed pot then see if the two keep in step, the map matches the standard one so no reason to suspect it.

Edited by Steve_T on Monday 13th July 13:39

[pat_y]

Further investigation this evening shows that adaptive 1 is acually ok at 2.5K revs, but adaptive 2 is nearly 30 at 2.5K revs, tickover only shows adaptive 1 at +9 and adaptive 2 at +2.
Fault screen is showing bad AFR on bank 2468 (same as my adaptive problem side). there is no fault logged for lambda or throttle pot that i can see.
i captured a run to see if anyone can see what the issue is here (hopefully the resolution is good enough).
I'm getting a bit stuck with this now as i'm not sure what to do, should i balance the adaptives/throttle pots at 2k revs rather than tickover?

any help would be very much appreciated.
thanks
pat

[Steve_T]

Are both pots ok? If you're running off 1 pot only and the physical angles of the throttles are different such that shared throttle % value is far too low compared to the real throttle angle then the ECU will try to compensate significantly via the adaptives. I thought 30 was about the max that was applied, so it suggest things are a long way out of whack and need sorting properly (Anyone?).

[pat_y]

I did think that Steve, that perhaps 1 pot had gone down and the whole system was running off the good one but when i unplug a TP when running i get a MIL light and a TP fault on the software. This doesn't happen through normal running and the fact that they are reading slighly diffrently all through the rev range makes me think they might be working OK.
I'm a little confused how the adpatives and tp balance can be quite good at tickover, but adaptive 2 almost off the scale at 2000 revs.
I tested for play in the throttle linkage but can't feel any.
Next stop i fear might be Andy at APM again, don't get me wrong i think the guy's an absolute gem but it's over an hour just to get to him.
Andy, if you're reading please move further South please, preferably Southampton way would be good.