Ford 351W TFI MS3.57x - Tip in going lean

[Blue Coupe]

Hello,

I have a Ford 351W TFI with an MSD running full sequential injection with 3.57x.
The 4 wire Stepper motor is disabled until I have the basics working, bi-pass port is taped off on the throttle body.
Currently only running a wide band, no narrow band 02 sensor.

Starts and idles well.
Issue: Tip in (light throttle) from idle the car hesitates and goes lean.

Attached is the tune and a short log file.
I tried turning off the AFR/EGO correction, increased timing and adjusted the Time based Accel enrichment with no material improvement.

Suggestions?

Thank you,
Erik

[slow_hemi6]

Is this engine seriously turbocharged? If it is not then it is a waste of the table to have the load scaled to 400kpa. You will need more table resolution from 70kpa to 100kpa. I am going to make a guess that this car does not have a std/mild cam as it is idling at 70kpa. Trying to target an idle afr of 14.7 with a half decent amount of overlap is unrealistic. It will be much happier targeting mid 13's afr at idle and it will help with the transition off idle. With an increase in table resolution you will also be able to increase more VE cell values better to cover the transition as well. What you have shown in the log is not enough change for AE to factor in, yet.

[billr]

What caught my eye is that the VE values are so very low, about 1/2 of what I expect, even though the req_fuel seems to have been calculated correctly. Something is wrong there, no engine will breathe that poorly across its entire operating range. Have you flowed the injectors to measure the flow rate at your fuel pressure?

[Blue Coupe]

The engine is not turbo charged. Running a mild hydraulic flat tappet cam with 2bbl Cleveland heads; with carb it pulls hard to 6300rpm.

I'll try richening it up.

billR good catch on the ve tables. I had to reduce them by half to get the idle AFR from 11.6 to the high 14s. I applied the reduction to the entire table, even though only about 10 cells have only been used so far.
The injectors are Ford SVO 30 lbs red tops.

I'll check the fuel pressure....once I find my gauge. I can also flow the injectors if necessary.

Hitting the throttle is almost a delayed reaction. Transitioning to 10%, the engine will hesitate then begin to increase in rpm. At higher rpms ~ 1900 the engine is much more responsive.

[billr]

Have you been driving it, or has all running only been at idle?

[Blue Coupe]

No driving, it's on jack stands. The hesitation would-be brutal...and I'll drive just about anything.

[billr]

I encourage you to go ahead and try it on the road. Pick a time when there is no traffic, so you don't have to bring it to a stop and fight the idle/tip-in too much. Either use the VE generator to get a more realistic table, or just try it as-is and hope VEAL gets you in better shape quickly. If you use VEAL, be sure the threshold temp in the "warmup" filter is set pretty low, no use having to drive it with a very poor VE table until the engine manages to get hot and VEAL can start! A vehicle with a 351 should be drive-able with no AE, if it isn't in something like a 3-yard dump truck.

[Blue Coupe]

I think you're right a drive might be best, I have quite a few wires to clean up first.

I tried richening the idle to low 13s:1 and the Tip in lag was still there and a bigger pop if I hit the throttle quickly. I also noticed that if I slowly open the throttle and rpms rise the AFR was a solid 13:1 (off idle cells were richened as well). The injectors can provide the fuel, they are just lazy slow reacting.

I'll have to read up the on VE table generator, I logged everything possible and the generator is stating RPM, EGO cor1, AFR, VE Table1 and CLT are missing. I'm not certain where the software is looking for these values as each is selected in the playback as well.

[Blue Coupe]

Update:
I drove the car today about 10 minutes on auto tune the and tip in began to improve (VE table changed significantly to larger numbers 50-60ish). After tip in at lower speeds there is a lot of bucking. I'll provide another update once I have more time on the road.

[ZOOMZOOMs]

my 02 .. use a larger tps dot , at least while still tunning low rpm afr... is possible that the " low speed bucking" that you feel is generated by too low tps dot , that over enrich with little throttle movements... i suspect is a stick shift car....

work your afr´s first, and ignore the accel hesitations... when you´re satisfied with the afr start to work on the accel enrichment.... start with a tps dot of 200, and lower your TPS BASED AE curve so it don´t interfere with your tunning stage..

take agood log driving slow , so we can have a better idea!

Juan

[billr]

Post new MSQ and MSL, now that you have had it on the road and given VEAL a chance. That bucking may simply be AE coming on when not needed.

[Blue Coupe]

I drove the car today using the VE auto tune and it worked quite well at first. The TIP in issue improved but more bucking at lower speeds. I had to stop tuning since I think my wide band is completely inaccurate and the tune went pig rich and my wide band still stated Mid 13s at the richest point. BTW I am only running a wide band no narrow band.
Have a look at the massive numbers in the VE table and I'll include a short data log for only for entertainment purposes. The good news is the car was pulling reasonably hard to 6200rpm at one point...then the tune with further adjustments went south.

Sample plug

Plug.jpg