99GTvert

Got my car back from a shop. The battery had been disconnected for at least a week. The car hesitates to accelerate but it idles OK. It has bolt ons (EGR deleted) with a dyno tune and it did not do this before I brought the car in.

The shop mentioned something about the car's computer having to relearn stuff for 50 miles or so..I wish they would have told me this before I went back again but anyway, does that sound about right? Do you think I need to re-upload the tune from my SCT2 handheld? I may try that anyway but I just don't see how the tune would be wiped out from just disconnecting the power.

cliffyk

Having the power disconnected for more than 5-7 minutes causes the KAM (Keep Alive Memory) in the PCM to be cleared. The KAM is where learned operating parameters such as idle air, and short and long term fuel, trims are stored. The "tune" is not affected by having the battery disconnected as it is stored in EEPROM (Electrically Erasable Programmable Read Only Memory), aka "flash memory". Reprogramming the tune won't hurt anything.

What sort of work was done while it was at the "shop"?

It is possible that the problem you are experiencing could be KAM related, however the fuel trims would have had to have been way off before clearing the KAM to make it behave as you describe.

If it hasn't straightened out after 50 miles something is wrong...

99GTvert

Thanks cliff. They replaced the cylinder head to fix a coolant leak because a head gasket went bad. I have put on about 30 miles or so, all on city streets with plenty of stop n go (no highway cruising). I'm going to drive it some more and see what happens.

99GTvert

Went over the 50 mile mark and its still being a piece of ****. Going to upload the tune to see if dumb luck will make it work, if not then back to the shop.

99GTvert

60+ miles & one re-upload of the same tune later, still feels like there's a restriction/stutter/hesitation. Back to the shop!! Weee!!!

JeremyB

if they put a new cylinder head in, it may have a break in period, but i'm not sure. I'm pretty sure there is a special procedure you have to do after installing the head to get it broken in.

russellthelovemuscle

Sounds like your running a little lean. If you got a Dyno tune you should tell your tuner he needs to readjust your air fuel ratios

2k1saleen

I just had my cylinder heads replaced with MMR Stage 1 and it does the same thing....it is really annoying after spending over $3000 it feels weak as hell. I been asking around and they told me to get it tuned and upgrade my fuel injectors and fuel rail because there is not enough fuel coming in to compensate for the air goin in. Im gonna try the injectors and rail first and see what happen.


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cliffyk

Whoever said you need aftermarket fuel rails is an āss do not believe another word they tell you. The stock fuel rails are good to over 600 HP at 40 psi, 1200 at higher pressures-- here's Kenne Bell's white paper stating same.

There is truth in the higher capacity fuel injector suggestion. Your 2001 came with 19 lb/h (orange) injectors that max out (95% duty cycle) around 290 fwHP, 245 at the wheels. In late '02 Ford admitted this and changed to 21 lb/h unit (pink) that can support 320 fwHP and 272 rwHP at 40 psi.

What you need are the FRPP 24 lb/h injectors, they are good to 365 at the crank, and 310 at the wheels; at 40 psi.

Unfortunately the FRPP M-9593-AA302 24 lb/h injectors are out of production, they were going for $170 a set after being discontinued however a quick "Google" does not show anyone still stocking them.

2k1saleen

Cliffyk, thanks for your info it was helpful...I made an appt at a dyno place to get it tune and the guy there told me not to change the fuel rails neather, injectors might; because I got well over 300hp and it might be cutting it short, but we'll see.