charr33

Ok, before I start, it should be noted that I did some searches, but due to the randomness of these symptoms, I wasn't able to pin point anything that matched up.

Car just brought out of storage last week. Did the oil change and fired it up.
Had to jump the battery. But other than that, it seemed healthy.
Took it for a spin to put air in the tires. Drove fine. (that is the key I think. It was working fine a week ago...what changed?)

Things to note. I believe the battery is dead. The gas in the tank has been sitting all winter (I'm not boosting yet anyways), and the spark plugs need to be changed. If any of these things could be causing this, let me know.

(Car is running on stock engine porting, rebuilt 20k ago, stock twins, stock boost, with a PFC. Open exhaust and intake.)

So I jump the car again this evening to drive it around for a bit. Starts ok with the jump. Sounds fine while warming up. Idle eventually settles down once the car is warmed up. Sounds fine. No problem.

Once I start to drive, I notice there is a yellow light in the bottom left of the cluster that has started to blink saying "4W ABS". Never seen that before. Never one to care much about ABS, I dont pay it much heed, other than to make a mental note to get it looked at next time its near a shop.

I turn onto the street and go through first gear, but the car starts to stutter. Almost like there is a hole in the fuel map. (I know there is an issue with my tuning, but it has never done this before) I would say its like safe mode, but you really couldnt drive anywhere like this. I cant even get over 3k rpm in first gear.

While this is happening I notice the odometer box seems to blink off and on randomly. I have never seen that happen before either. Seems to correlate with the bucking of the engine.

And when this happens I also get a "beep". The bad kind of beep that warns you to stop doing what youre doing or suffer the wrath of the rotory gods.

Further, I notice my headlights lose a bit of brightness when this happens.

AND I notice my PFC Commander is registering '---' in some of the fields. (I have had a similar issue which showed the PFC give a false reading of -35C before but never ---)

FINALLY, when reversing back into my garage, I notice that there is an odd whine coming from the right side (turbo side). Almost as if I had a supercharger instead of a turbo...That cant be good. But doesnt seem to be related (or maybe it is?)

So first I thought alternator, but then the car idles just fine. It revs ok (although I didnt really rev it past 4500 in neutral) and only gives the issues under load.

So I thought since it was a stuttering issue, it could be fouled plugs which I mentioned need changing. But why all the electrical issues?

Then I thought it could be the PFC itself. But would the car even run at all if it was messed up?

Finally, I am thinking it must be a sensor of some kind, and the PFC is trying to "tell me something" in its own way by sending these signals and perhaps retarding the timing. Maybe O2 sensor? Perhaps something on the turbo itself (caused by the fact that the turbos may be cooked as indicated by the whine?)

The fact that the car beeped at me seems to tell me that SOMETHING has sensed that there is a problem (or 2).

So has anyone had any experience with this kind of issue, or knows what sensor might be causing this (if it is a sensor), and if not, could it be the ECU?

Could we have bumped something when we did the oil change? Grounding wires?

Any help would be appreciated.
Thanks guys

Chris

Chadwick

iTrader: (12)

The first thing you need to do it get the battery issue fixed and see if you are still having problems. A lot of the systems and ECU perform differently under low voltage situations which can make for all kinds of weird symptoms.

Dan

RXcetera

I had the exact same symptoms when my alternator failed last fall.

Dusted RX

Same symptoms when my battery had a bad cell. Not enough juice to put the fuel pump to high speed.

zenofspeed

iTrader: (1)

Why don't you properly maintain the car before trying to diagnose "problems"?

IE (new battery, good gas)

Then get the alternator tested.

Dudemaaanownsanrx7

iTrader: (23)

agreed. get the basics out of the way. check your ground and power connections too make sure they are clean and tight. (not just the ones at the battery)

Neo

iTrader: (4)

Coming off a bit strong, huh?
It's not like he doesn't take care of his car. He just tends to worry it might cost him more than expected.

He'll get rid of the basics and take it from there.
Chances are good it'll either be the battery or the alternator.

Thanks for the input guys. He just needed confirmation, that's all.

charr33

Thank you all.

Battery replaced. Problem solved.

It just seemed too crazy to be the battery. I've had battery issues in the past, and it has never gone crazy like that before. Usually, the car just wont start.

Sorry to "cry wolf" but after 5 months of waiting to drive her again, this glitch put me over the edge...

Cheers