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Topic: Doe the computer have to "relearn" w/ HO swap? (Read 1624 times) previous topic - next topic

Doe the computer have to "relearn" w/ HO swap?

My 'bird is sputtering a good bit after the HO swap. When going slow and shifting smooth it does ok to about 4K then falls flat.  When jumping on it while driving it goes flat almost immediately from low RPM.

To add, I need to install the catback and I've not done any tuning to speak of other than set the timing to 12 degrees.  The only driving has been a mile down the road and back several times to get it up to temp and make sure everything works and does not leak.

The details....88 GT 5.0L, T5, DA9 computer, SD (did not convert to MAF), Mustang injectors, 70mm Edelbrock TB/EGR, 1-5/8" shorties, and BBK H-pipe.

The "relearn" part comes from a friend that I consider to me a VERY knowledge mustang guy.  He told me to fire it up and run it for a while to let the computer adjust for all the new parts.  Before I do this it needs more fuel and I want to run some Sea Foam through it.

Ideas?
1988 T-Bird Sport Coupe--5.0 HO, MAF swap, 1-5/8" shorties, BBK/Flowmaster exhaust, Explorer intake, 70mm Edelbrock TB, T5, B&M short throw, Centerforce clutch and PP, disc brake TC rear w/ 3.55's, TC front brakes, '98 Cobra springs, DIY SFC's, other misc .  14.05 @ 98mph with launching too low and shifting too high.

Doe the computer have to "relearn" w/ HO swap?

Reply #1 –
Not to discount your friend's input....but the only re-learning that takes place is the idle and some records later down the road used in Adaptive Strategy, or readings dubbed incorrect because they are too far out of range, that it needs to know are garbage. The point being that doing work like this, resetting the computer, and driving it for the first time ought to be just about hiccup-free.

Check your fuel pressure yet? Sounds like it's going dead lean, fuel pump or a blockage somewhere in the fuel delivery system. Especially since going WOT at any point causes it to die.
1987 20th Anniversary Cougar, 302 "5.0" GT-40 heads (F3ZE '93 Cobra) and TMoss Ported H.O. intake, H.O. camshaft
2.5" Duals, no cats, Flowmaster 40s, Richmond 3.73s w/ Trac-Lok, maxed out Baumann shift kit, 3000 RPM Dirty Dog non-lock TC
Aside from the Mustang crinkle headers, still looks like it's only 150 HP...
1988 Black XR7 Trick Flow top end, Tremec 3550
1988 Black XR7 Procharger P600B intercooled, Edelbrock Performer non-RPM heads, GT40 intake AOD, 13 PSI @5000 RPM. 93 octane

Doe the computer have to "relearn" w/ HO swap?

Reply #2 –
All the lines are new and I had the tank apart for a new sending unit.  I'm going to pull the TB and clean it...while that is apart I'm going to put a gauge on the FPR.  Forgot to add that I installed a BBK FPR also.......all used from a friend that was taking stuff off his Mustang.

Wish I had a wideband on it like my Ranger.

You mentioned "resetting the computer".  Was there something I was supposed to do to reset it??  I just yanked the stocker and installed the DA9.

Thanks for the input.
1988 T-Bird Sport Coupe--5.0 HO, MAF swap, 1-5/8" shorties, BBK/Flowmaster exhaust, Explorer intake, 70mm Edelbrock TB, T5, B&M short throw, Centerforce clutch and PP, disc brake TC rear w/ 3.55's, TC front brakes, '98 Cobra springs, DIY SFC's, other misc .  14.05 @ 98mph with launching too low and shifting too high.

Doe the computer have to "relearn" w/ HO swap?

Reply #3 –
I was guessing fuel also.  What condition is the pump?
Mike

Doe the computer have to "relearn" w/ HO swap?

Reply #4 –
Just unplugging the battery terminals in the course of swapping a motor in/doing any work like that is what I meant.
1987 20th Anniversary Cougar, 302 "5.0" GT-40 heads (F3ZE '93 Cobra) and TMoss Ported H.O. intake, H.O. camshaft
2.5" Duals, no cats, Flowmaster 40s, Richmond 3.73s w/ Trac-Lok, maxed out Baumann shift kit, 3000 RPM Dirty Dog non-lock TC
Aside from the Mustang crinkle headers, still looks like it's only 150 HP...
1988 Black XR7 Trick Flow top end, Tremec 3550
1988 Black XR7 Procharger P600B intercooled, Edelbrock Performer non-RPM heads, GT40 intake AOD, 13 PSI @5000 RPM. 93 octane

Doe the computer have to "relearn" w/ HO swap?

Reply #5 –
Mass-Air convert it. for real. You've swapped the injectors (which is the biggest deal for SD) and the throttle body, added headers, etc. The SD system relies on assumptions to work.  It has no idea how much air is moving through the engine, it only knows what to expect based on the MAP sensor and the O2s.  The SD system is calibrated to operate with stock or mildly worked parts.  Anything like what you've done is like moving the furniture around in a blind man's house; it can't cope properly.  MAF convert it, so that the PCM can make it's fuel calc based on an actual measurement of the airflow through the engine rather that how much air it THINKS is moving through it.

Doe the computer have to "relearn" w/ HO swap?

Reply #6 –
Don't knock SD too much. What do you want out of the car? A wild thumpy cam for nothing but top-end dragstrip power? A good street cruiser? Boost and lots of it? Yes it needs vacuum and most cams especially Ford letter cams aren't going to work. There are plenty of SD-friendly cams however. 20 years of technology helps ;). 
 
What he's done is perfectly fine. The only thing I think I'd change is the throttle body, and use a 60mm stock Mustang one because there's no point in the bigger TB when the opening on the upper plenum is jsut 60mm, and what the TPS is reporting is technically more airflow than what would be expected at that position. Of course, the TPS isn't exactly highest on the chain of command for fuel and spark calculation. The MAP reads vacuum or lack thereof and is king of the hill, so TB doesn't affect that negatively.
1987 20th Anniversary Cougar, 302 "5.0" GT-40 heads (F3ZE '93 Cobra) and TMoss Ported H.O. intake, H.O. camshaft
2.5" Duals, no cats, Flowmaster 40s, Richmond 3.73s w/ Trac-Lok, maxed out Baumann shift kit, 3000 RPM Dirty Dog non-lock TC
Aside from the Mustang crinkle headers, still looks like it's only 150 HP...
1988 Black XR7 Trick Flow top end, Tremec 3550
1988 Black XR7 Procharger P600B intercooled, Edelbrock Performer non-RPM heads, GT40 intake AOD, 13 PSI @5000 RPM. 93 octane

Doe the computer have to "relearn" w/ HO swap?

Reply #7 –
Oops......also have an Explorer upper and lower.

All I want is a cruiser with more oomph than a stock fox GT.
1988 T-Bird Sport Coupe--5.0 HO, MAF swap, 1-5/8" shorties, BBK/Flowmaster exhaust, Explorer intake, 70mm Edelbrock TB, T5, B&M short throw, Centerforce clutch and PP, disc brake TC rear w/ 3.55's, TC front brakes, '98 Cobra springs, DIY SFC's, other misc .  14.05 @ 98mph with launching too low and shifting too high.

Doe the computer have to "relearn" w/ HO swap?

Reply #8 –
Nothing wrong with the intake either, so actually yea keep the TB haha. 19# injectors are just fine with that as well. I bet you've got a fuel supply issue and once that's sorted out you'll be right as rain.
1987 20th Anniversary Cougar, 302 "5.0" GT-40 heads (F3ZE '93 Cobra) and TMoss Ported H.O. intake, H.O. camshaft
2.5" Duals, no cats, Flowmaster 40s, Richmond 3.73s w/ Trac-Lok, maxed out Baumann shift kit, 3000 RPM Dirty Dog non-lock TC
Aside from the Mustang crinkle headers, still looks like it's only 150 HP...
1988 Black XR7 Trick Flow top end, Tremec 3550
1988 Black XR7 Procharger P600B intercooled, Edelbrock Performer non-RPM heads, GT40 intake AOD, 13 PSI @5000 RPM. 93 octane

Doe the computer have to "relearn" w/ HO swap?

Reply #9 –
Fuel pressure. I had the issue not very freakin' long after I swapped in my HO..was a fast-dying f/p.

And hey, ole dude that's hawking the mass air conversion....stock for stock, a speed density system will run a bit harder than a mass air setup....he doesn't need m/a unless he changes cams, or gets a crazy set of heads. SD will run and run ed well with what he has now....and I am not the only one that will stand by this.
'84 Mustang
'98 Explorer 5.0
'03 Focus, dropped a valve seat. yay. freakin' split port engines...
'06 Explorer EB 4.6
 

Doe the computer have to "relearn" w/ HO swap?

Reply #10 –
Vac,intake leak?
Old Grey Cat to this.88 Cat, 5.0 HO, CW mounts, mass air, CI custom cam, afr165's, Tmoss worked cobra intake, BBK shorty's,off road h pipe, magnaflow ex. T-5,spec stage 2 clutch, 8.8 373 TC trac loc, che ajustables with bullits on the rear. 11" brakes up front. +