AFR tuning - cannot adjust properly
AFR tuning - cannot adjust properly
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Discussion

Wolvesboy

Original Poster:

597 posts

158 months

Tuesday 9th July 2019
quotequote all
Hi All,
New coil packs, MSD leads/caps, plugs, lambdas, injectors, adjustable fuel regulator, fuel filter. Repaired air boxes: still cannot tune adaptives correctly.
Wound off idle. Reset throttles to 16.9 balanced both together, upped idle screw (both) to 18%. Started and over fueling massively, attempted to minor adjust TPs so I could attempt to drive her up to temp. Adjusted idle to 950ish. Like A PIG (both adaptives 30+). Warmed up and could not adjust adaptives below +12 - would not adjust anymore. Fuel smell overbearing, coughing & spluttering. Just the as same before I changed the "knackered" injectors. I've done this procedure multiple times, placing the Throttle pots in the middle to give more adjustment but nothing works. The overfueling is ridiculous. The TPots bought online just before the group buy, swapped then over numerous times with same results. Sick of this s**t engine.

Jhonno

6,191 posts

158 months

Tuesday 9th July 2019
quotequote all
Wolvesboy said:
Hi All,
New coil packs, MSD leads/caps, plugs, lambdas, injectors, adjustable fuel regulator, fuel filter. Repaired air boxes: still cannot tune adaptives correctly.
Wound off idle. Reset throttles to 16.9 balanced both together, upped idle screw (both) to 18%. Started and over fueling massively, attempted to minor adjust TPs so I could attempt to drive her up to temp. Adjusted idle to 950ish. Like A PIG (both adaptives 30+). Warmed up and could not adjust adaptives below +12 - would not adjust anymore. Fuel smell overbearing, coughing & spluttering. Just the as same before I changed the "knackered" injectors. I've done this procedure multiple times, placing the Throttle pots in the middle to give more adjustment but nothing works. The overfueling is ridiculous. The TPots bought online just before the group buy, swapped then over numerous times with same results. Sick of this s**t engine.
Adjustable fuel regulator? Why? All manor of issues potentially with them from my experience. Including leaks.

Have you wound off idle stop, removed the linkage bar and started from there? Have you had a syncrometer on the banks?

If you are saying it is + on the adaptives it is running lean, and adding fuel.

What are your lambda traces like? Are they the correct way round?

Byker28i

77,500 posts

234 months

Tuesday 9th July 2019
quotequote all
Fire up the diagnostics and reset the adaptives to start with?

Wolvesboy

Original Poster:

597 posts

158 months

Tuesday 9th July 2019
quotequote all
Thanks for the quick reply.
Yep, I completely wound off the idle screw. Balanced from there. Lambdas brand new and correct placement.
The only thing I have not done is the air measurement -I don’t have that piece of equipment. Too much air so you could be onto something with the air flow through the butterflies. I’m not sure how much “flow” is correct for a 4.5 and how to adjust them.

Jhonno

6,191 posts

158 months

Tuesday 9th July 2019
quotequote all
Wolvesboy said:
Thanks for the quick reply.
Yep, I completely wound off the idle screw. Balanced from there. Lambdas brand new and correct placement.
The only thing I have not done is the air measurement -I don’t have that piece of equipment. Too much air so you could be onto something with the air flow through the butterflies. I’m not sure how much “flow” is correct for a 4.5 and how to adjust them.
4.5 should be 14/15% TPS value @ idle.

FarmyardPants

4,256 posts

235 months

spitfire4v8

4,018 posts

198 months

Tuesday 9th July 2019
quotequote all
You say it's overfuelling massively but you also say the adaptives are not at their limit 0f 37percent. The two cannot exist simultaneously, assuming no faults.

How do you know it's overfuelling?

If the adaptives are less than +/- 37percent, and the lambda traces in the live diagnostics screen are swinging violently up and down, then the ecu has achieved lambda=1

I used to get hung up on achieving close to zero adaptives, now I don't and haven't for over a decade or so. The adaptives will be what they will be - assuming you have about equal airflow bank to bank and the throttle pots are about equal bank to bank and somewhere around 15-17 percent then it should at least run fine.

What you've done so far sounds fine as a basic up and running set up.

Demondad

482 posts

232 months

Wednesday 10th July 2019
quotequote all
I'm no expert on this but one experience of something similar was solved by simply taking it for a gentle run to 70-80, up and down the gearbox. The adaptives need some time to adapt I guess and all was solved after 5-10 miles. The same happened when my lambdas were connected the wrong way round. It took 5 miles gentle driving after the connection was corrected to settle down. Leaving it idling doesn't seem to work.