So I replaced the battery yesterday on my car.
Fired it up and attempted to take it for a drive.
I got about halfway down the street and noticed the car wasn’t running right at all. (I let it warm up)
Was stuttering and bogging etc… idle sounded OK though.
Car is tuned with a piggyback ecu, also have an HKS VPC (Soon getting replaced by AEM EMS).
Could a battery change make a car lose it’s tune? I didn’t think so… Been banging my head against the wall for a few days.
Mods:
So far I’ve:
Swapped the plugs out for NGK BRK7e’s to see if that was the issue. Negative. Car does the exact same thing.
I tried resetting the ecu fuses, checked the battery cables, still no good.
Can anyone reccomend anything else?
spend the extra money and get the motec m600. any luck on supra forums? id look there for help or talk to travis.
boost/vac leak is what I’d check for first. Thats a common problem with any forced induction vehicle. Some cars won’t even idle with a small leak.
Tried on supraforums, still havn’t come up with much.
I know Travis is pretty busy, I pmed him before.
it was running normal when last parked, battery died and now its where youre at now, is that correct?
if thats the case, i highly doubt its a vac/boost leak. its probably related to the VPC. how is the data stored with the vpc as far as the adjustments, its been a while since ive seen one or dealt with it… time to MoTec it!
it was running normal when last parked, battery died and now its where youre at now, is that correct?
if thats the case, i highly doubt its a vac/boost leak. its probably related to the VPC. how is the data stored with the vpc as far as the adjustments, its been a while since ive seen one or dealt with it… time to MoTec it!
I know. VPC is old school technology. I’m not sure how it works entirely. I’m going to be getting AEM EMS. Maybe this is god telling me its time.
LKSi
September 21, 2008, 6:00pm
7
Unhooking your battery resets the ECU… so maybe your tuning thingy got reset too!!!
Thought about that… but several people said it shouldn’t reset the tune.
prolly not gonna reset it but it could of thrown off some sensors that will need a relearn like i.a.c but if it runs rough all threw the range id check a maf sensor and see if its shitty or if suttin got unplugged accidentily
LKSi
September 21, 2008, 6:27pm
11
I would think it was the piggy back … interesting.
i thought the vpc was an actual set of knobs to tune.
search for injector battery offsets, thats all i can think off
Singh1
September 21, 2008, 6:57pm
14
damn this is crappy news
the only advise i usually give is
turn it off, and turn it back on again, then call me back
Shoulda bought an E36 M3
/thread
He had an E46 M3 before the Supra… :headbang
And two e36 m3’s… The Supra has been crazy reliable for the HP it puts down. I cant complain. I’m thinking the ECU needs to relearn, and I need to drive it around for an hour or so and see what it does. I ended up breaking a crankcase hose because it was dry rotted when I swapped the plugs. So I’m waiting on that part.
I’ll take this problem car off your hands…
And two e36 m3’s… The Supra has been crazy reliable for the HP it puts down. I cant complain. I’m thinking the ECU needs to relearn, and I need to drive it around for an hour or so and see what it does. I ended up breaking a crankcase hose because it was dry rotted when I swapped the plugs. So I’m waiting on that part.
the isolator hoses between the valve covers? if so, normal heater hose would work just fine, i think its 1/2" id.
thats what i remember. its all analog
lconrad
September 22, 2008, 4:49am
20
i’m pretty sure his setup is a piggy back…so he’s not able to change anything…it may just have to relearn