Engine problems after battery short circuits?

spetz · Post by **spetz** » Mon Feb 27, 2006 11:41 pm

So,
A friends battery went dead. We filled it up with distilled water and got it jump started.
We unbolted it from the mounts to open all the little caps, but never bolted it back in properly.

Then, we thought we would rev it to charge it up, but on acceleration the battery moved backwards and the +ive hit the strut brace, everything switched off for a second and then went back on.

Now, the car isn't running properly, it's low end power is good, but it runs out of puff at around 6000rpm. The induction roar is much much louder, and in MIVEC it screams.
It also idles quite high (1500rpm or so) and sometimes at those revs, the revs suddenly drop then go back up.

The battery has been changed already, checked cam timing, and looking for any vacuum leaks but couldn't find anything as of yet.

Any ideas?
Help someone...

DIGGIDY · Post by **DIGGIDY** » Tue Feb 28, 2006 4:33 am

Not a very clever thing to do..

I'd try the basic's like check all fuses, and a ECU reset, see how much difference that makes..

if your still getting problems, check the stepper for faluts(idilng problem) and maybe the intake control valve on the plenium as well, if you've not got the dual runner flaps open in the mivec range, your gonna loose a few ponnies...

scarecrow · Post by **scarecrow** » Tue Feb 28, 2006 10:10 am

Those f**king strut braces... there should be a warning on them

I took the battery out to give it a clean, and when i put it back in i started tightening it with a spanner, ended up turning it too far and it came in contact with the strut brace... took a chunk of metal clean out of the spanner, and punched a hole in my skin plus gave me some awesome looking scorch marks.

Cars fine but.

Dr_Jones · Post by **Dr_Jones** » Tue Feb 28, 2006 12:01 pm

It's not the strut brace that should come with a warning it's people.

Positive should be the last off and the first on, eliminating (mostly) the potential for a short circuit. I also have a very tidy piece of rubber hose around my brace should the battery decide to move.

spetz · Post by **spetz** » Tue Feb 28, 2006 1:25 pm

We took off the valve control and the worm drive works (you can see/feel/hear it spin at 4500 rpm)

We did reset the ECU, not only that but we even took out the ECU from my car and swapped it over just incase the short circuit stuffed the computer, but same problem.

Would the TPS show up with an error if it was faulty?

And the stepper motor, would that make the car lose all it's top end? MIVEC is useless as it's got more power before it now. But it just makes about 3X more noise now

Post by **Bennoz** » Tue Feb 28, 2006 1:38 pm

Yeah I'd be having a look see at the error codes... heaps of sensors that could be out or have fuses blown that run them

11 Oxygen Sensor
12 Air Flow Sensor
13 Intake air temperature sensor
14 Throttle position sensor (TPS)
15 ISC Motor Position Sensor
21 Engine coolant temperature sensor
22 Crank angle sensor
23 Camshaft position sensor
24 Vehicle speed sensor
25 BARO Sensor (listed as 26 in one info source)
31 Detonation sensor
32 Vacuum sensor
36 Ignition Timing Adjustment Signal
39 Oxygen Sensor
41 Injector system
42 Fuel Pump
43 EGR
44 Ignition coil and power transistor unit (Cylinder 1 & 4)
52 Ignition coil and power transistor unit (Cylinder 2 & 5)
53 Ignition coil and power transistor unit (Cylinder 3 & 6)
55 Idle Air Control Valve/Servo Valve Position Sensor
61 Communications wire with A/T-ECU
62 Intake air control valve position sensor
64 Alternator FR terminal
71 Vacuum control solenoid valve (TCL)
72 Ventilation control solenoid valve (TCL)

spetz · Post by **spetz** » Tue Feb 28, 2006 2:19 pm

The ECU doesn't come up with errors...
It did once with 62, but reset it, player around with the worm motor and it works fine now.

other than that the ECU is clear (just keeps flashing)

Post by **Bennoz** » Tue Feb 28, 2006 3:41 pm

So its all fixed?? What do you think did it, the reset?

Im curious as I've been asked about this problem before (battery shorting)

spetz · Post by **spetz** » Tue Feb 28, 2006 9:23 pm

No the ECU reset didn't do anything.

The car still has this problem.

Put it on a scan tool and everything seems to be working properly without errors coming up. It doesn't "seem" to be an electrical problem.

What I have also noticed is that the exhaust is a lot quiter. So I am thinking maybe at the time of the battery short circuiting, excess fuel was dumped into the exhaust and it destroyed the cat?

Temperature readings show the cat is fine, but on thursday will take it off to check.

Post by **Bennoz** » Tue Feb 28, 2006 11:29 pm

If your cat was fried you'd get error 39 Oxygen sensor. I think you've fried the ECU....

spetz · Post by **spetz** » Wed Mar 01, 2006 2:03 am

No it can't be the ECU as we put my ECU into his car and it had the same problem.

Would error 39 definately come up? Maybe the cat is just restricting air flow now (like putting a tiny exhaust on).
Because that's what it feels like, the car has more torque down load, no power up high, the exhaust note is heaps more quiet, but induction noise is much louder

spetz · Post by **spetz** » Thu Mar 02, 2006 10:58 pm

I thought I would let everyone know that the problem was found.

I was correct and it was the cat that was destroyed. $380 later it has a high flow full stainless 3" cat in it

Post by **Bennoz** » Thu Mar 02, 2006 11:25 pm

Well I'll be! Nice find

DIGGIDY · Post by **DIGGIDY** » Fri Mar 03, 2006 4:34 am

I take it you put the control valve back on correctly?? remember it has to be put on and rotated into place where the bolt holes line up... and the motor has to be set in the correct postion as well... if you got it wound back the wrong way it isn't going to function correctly, and you would loose top end...

spetz · Post by **spetz** » Fri Mar 03, 2006 5:31 pm

I am pretty sure the motor was put back in the right way.

The car was free revved with the motor off and I checked into what direction the worm drive spins, and from then on I just held the intake valve control on full closed position (not it's free state) with a small screwdriver and put the motor/drive onto it