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1966 EType Jag 4.2Ltr Manual (rebuilt engine) 9.8:1 190PSI each pot
Conversion to fuel injection (6 injectors) 450KPA Fuel Pressure
M130 ECU / Fixed Dissy / reluctor wheel / MAP / IAT
Converted to run E85
The tune on throttle is fine and on a dyno the lambda looks good .90 to .85 across the range . Makes good power and is smooth all through rev range.
My issue is a lean hesitation on throttle initial throttle opening. I have seen 1.7 to 2 lambda
I have played with the fuel film simple settings , it is set to 115% ( i have tried it up to 250%)
Idle is good and timing at idle control is between -5 and 15 Degrees at .99 Lambda
we are using the triple SU's with dash pots etc. removed and the throttle blades as air intakes through the std e type air cleaner
does anyone have any ideas for me as to what I can do to mitigate the hesitation.
How about some logging showing the issue? Show us what happens with different Fuel Film Primary Scale values? You might also want to play with Fuel Film Primary Offset -- this is calibrated by looking at the lambda value following a fuel cut (usually done with an overrun). See the help for "Fuel Film" for some details on this.
Do you have level 2 logging enabled on your M130? If so, log Fuel Film Calculator.
Since you are using the distributor -- can you confirm the engine runs without misfire at all the Ignition Timings you see in the logs? Sometimes the distributor needs to be clocked so that the rotor will still connect at the complete range of ignition angles.
Road car multi-throttle engines can be a major ball ache to get right with M1. Manifold pressure mode needs to be set to estimate and the shape of the MAP estimate table is critical for the fuel film model to work correctly - you cant just do a linear 0-100 or 30-100 like the help suggests for a road engine. The couple I have done have taken many hours of messing around with the MAP estimate table to give something that allows the film model to work acceptably at small throttle openings. Even after getting it good enough that it drove ok without flatspots etc, the lambda trace never looked great... Of course, every time you adjust the MAP estimate table you have to retune the VE table as well so it is a fairly painful process.
Also I will emphasize what David has mentioned about the distributor rotor phasing. Be aware with a locked distributor the maximum timing variation you can command is limited by the angular width of the tip of the rotor. So if for example your rotor tip is only 25 deg wide, you need to be careful with how much advance you command during cruise conditions - especially if you are using idle ignition etc. I imagine the old Jag hemi chamber probably wants way more advance in some conditions than will actually be possible with a locked distributor.
Thanks for the responses , the car runs fine in all other areas except the hesitation from crack of throttle. Revs cleanly to 5,500rpm red line
I will log the car today using those settings and post it up here.
Thank you again for your time with this issue .
Good observations about the distributor, or more accurately the rotor, phasing to the 'plug terminals. Even with the original operation, it wasn't unknown for the rotor tip to be misaligned either at idle, when fully retarded, or when fully advanced, as different aftermarket suppliers may have the alignment slots in slightly different positions, or there may be variations in the base-plates, etc.
Fortunately, this is quite easy to check and set, easier than with points, but requires the sacrifice of a distributor cap.
It's been many years but if I recall correctly -
Remove the HT leads.
Check the position of the clip points and the locating lug on the underside that aligns the cap to the slot in the body - you need to make sure these are left in place.
With a hacksaw, or other cutting blade, cut away the cap in the area around one of the plug posts - or several to ensure you can see inside clearly. You need to leave enough material to ensure the posts are still held solidly in place but remove enough to see what the rotor is doing.
Refit the HT leads and fit to engine.
Connect your favourite timing light to the plug wire that is on the most visible post and start the engine.
By using the timing light you should see the rotor illuminated with the tip aligned to the distributor post and by moving the dis' body you can change the relative positions so there's an overlap from idle to full advance.
I would suggest setting the timing to zero for rpm and load corrections, and have it just overlapping, that way any rpm and/or load correction advance will increase the overlaping of the tip and post. Then add the advances and check you still have overlap.
That may not be too clear, but with a little thinking about it, you should be fine.
just an update , found the issue with the tuning of the jag the fuel numbers were way to low for e85 specifically the enrichment based on MAP
if anyone would like the figures I will post them here for you.