Ford Racing 5.2L Aluminator 5.2 XS Crate Engine Idle issue

[MPE Racing]

Hi there all,

Been on here for years and haven't posted much, if any, but I am in need of some help from you guys today. I have a 5.2XS crate motor with a FRPP Controls Pack and I cannot for the life of me get it to idle well, if at all, once the fans come on. Cold start good? check, Hot start good? check, WOT good? check.

I got everything out of the way and then noticed the idle was really surging with the A/F ratio wigging out so after going through all the throttle body settings (IPC error was all over) and whatnot I got it to idle like stock, drive like stock and making what I would consider the correct HP & TQ (490 RWHP and 380 RWTQ on a 94-degree NE day so I think the power seems good) but the minute the fan comes on it all goes to hell. I have read post after post and found guys with the identical issue and did what was recommend tried changing the ETC Predicted, Driver Demand Table, Torque & Inverse Tables, Idle Torque Proportional & Gain tables plus a ton of other changes but I am out of theories and ideas. Any feedback and opinions would be greatly appreciated. Thanks, Chris

[mstang_man]

little fat on idle, idle torque min & max are low, stock is max 55 min -55. min throttle angle 0.625 you have (0), there are some other adjustments i would probably make. what is the throttle body 87mm or 90mm? gt350 intake correct? did you try raising the idle speed neutral and in drive? stock 625 raise to 750.

[MPE Racing]

Thanks for the reply... I had taken 3% of fuel out after that data log but the engine when then hot so I failed to mention I already cleaned up the MAF... I had already tried these items and the vehicle runs worst now than before, see attached. It seems to be happier at the 625 and maybe it's because the RPM axis but I didn't play with it because it idled so nice at 625. Since it now runs a lot different with just those two changes does that make any sense?

[mstang_man]

Thanks for the reply... I had taken 3% of fuel out after that data log but the engine when then hot so I failed to mention I already cleaned up the MAF... I had already tried these items and the vehicle runs worst now than before, see attached. It seems to be happier at the 625 and maybe it's because the RPM axis but I didn't play with it because it idled so nice at 625. Since it now runs a lot different with just those two changes does that make any sense?

this an actual 5.2aluminator? cobra jet intake and twin 65mm cobra jet Throttle body? the ETC effective and predictive appears off to me. you said you change those and the torque and torque inverse? still rough idle?

[MPE Racing]

Yes sir, this is an actual 5.2XS crate motor with a CJ intake, twin 65mm CJ throttle body and FRPP GEN 2 Controls pack... I used the effective and predictive data from an 15-17 Roush Phase 2 file I had because the only CJ tb info I had and have seen only has 14 columns of data that works for 11-14 Gen 1's but the 15-up has 18 columns of data needed so I tried to interpolate the missing data and it ran and idled but only with 5 degrees of minimum throttle angle. Once I used the Roush data the car idled great but still had the surging and eventually stalling issue when the fan came on. I initially thought it was just fan wash because the MAF sensor is right behind the fan, but I installed a heatshield on the filter, and all it did was raised the IAT's into the 150's and still had the fluctuating A/F ratio, surging and stalling.

[engineermike]

Idle torque reserve?

[MPE Racing]

Thanks for the reply Mike. I played with those values a little bit but it dint seem to make any affect but I may not have been making big enough changes. What kind of numbers should they be? Any idea? Thanks, Chris

[engineermike]

I was just thinking that the goal of torque reserve is that’s the torque left on the table, attainable with spark advance, so if the load changes at idle then the spark advance can very quickly come in and stabilize it. Cooling fans will cause a sudden increase in load, so torque reserve came to mind.

Another potential issue is “wash” from the fans causing noise in the maf signal. Can turbulence from the fan reach the maf element?

[MPE Racing]

Hey Mike,
Yeah, I already thought about the fan wash issue and talked about it in a earlier post. With a shield on the filter, it didn't change anything but made the IAT's go in the 150's.

[mstang_man]

Hey Mike,
Yeah, I already thought about the fan wash issue and talked about it in a earlier post. With a shield on the filter, it didn't change anything but made the IAT's go in the 150's.

i think mike has hit the nail on the head, the load increase as fans kick in, general load at idle is around 15-20 and that initial surge of 40 amps increase load to around 25-30 as the ETC compensates for the increase. I am not sure what we are missing in the tune.

[MPE Racing]

OK, so I have had a little bit of sucess today with the tune. I played a bunch with the Idle Torque Reserve going up to 50 and then down to -40, I honestly wasn't sure which way to go. I bumped the min idle throttle angle to 1.5 but it didn't do anything. I played with the Driver Demand tables some more and that also didn't do much. The major things that seemed to help was the ITR and we turned the MAF sensor up and away from the fan (that might have been what helped but I am not 100%). Anyway, I have a couple logs now (one at 625 Idle and one at 750 Idle) they both run about the same, but it will at least idle with the fan on now. So, now it's down to the surge with the spark advancing and subtracting with the A/F freaking out a bit. Any ideas, fellas?

[MPE Racing]

The major issue I see on the data log is the Idle Torque Base & Idle Torque Instant Correction. When that is about the same the surge is gone, and the A/F is fine. How to you correct the IT Base and IT Correction then? Proportional & Integral values?

[veeefour]

We tuned this engine with gen 2 and also with gen 3 PCM paired with 10r80...there is a ton to change for this to ilde OK-ish

TB data is fine, you can have few last or few first rows the same if the data has lower resolution...