Booztd 3

Not sure if anyone is following but here is the preface:

1994 touring--its a friends car
Grenaded motor a few months ago. I installed:

Atkins 13B Ported/Polished Motor

EVERYTHING else is stock on the motor.

After getting the car started and running, aside from the misc cooling issues and vaccum line issues these things have, its running "ok"

The car is throwing code 5 (which is a knock sensor code.) The car is puffing black smoke at idle (unburnt fuel) My guess is the ECU is picking up the knock sensor code and dumping in extra un-needed fuel to compensate for the knock. Is it possible the car is actually knocking at idle? I've cleared teh codes before, double checked they were cleared, fired it up, only to see the CEL go on again, resulting in a code 5 once again.

Since the motor is ported and its on stock everything else, is it possible its sucking in to much air for the stock computer to handle, and its actually going lean at idle and knocking? Anyone have any input?

re_rotary7

dont know if a knock can occur at idle, I think it would just stall before that happens. If its throwing a knock sensor code that means that there is a malfunction with the knock sensor itself or the wiring to it. might try replacing it, these go bad.

Kento

Depending on how much "porting and polishing" was done, the idle mapping on the stock ECU probably will never be correct for difference in intake pulses that a ported motor has. I doubt that the knock sensor problem is affecting the idle mixtures. Detonation really only occurs under load.

quid

have you done anything with the timing?

BlueSprite

i believe timing is adjust by the ecu itselt.
my friend had a knock sensor code before, but once he replace it and reset the ecu; the code was terminated. (he is running PFC now)
Could be the map sensor too....

Correct me if i m wrong

Booztd 3

Hrm thanks for the suggestion guys. I'm currently researching on how to "fool" the ecu into thinking a knock sensor is present (probably by placing a specific resistor into the wiring harness)

I checked the wiring harness and all thats supposed to be present between the harness and the ecu is continuity to ground. That all checks out

Mahjik

iTrader: (1)

The knock sensor isn't a simple "on/off" switch like the solenoids. Just replace it with a new/used (working) one or get an aftermarket ECU which ignores it (like the PFC).

Booztd 3

I'm only trying to fool it, to figure out whether or not it really is an issue with the knock sensor itsself, or if its another issue (wiring perhaps)

Mahjik

iTrader: (1)

You'll be better off just borrowing one from a working car and testing it. Then you'll know if replacing it will fix the issue or not. I'm sure there is someone around that area with and FD who would let you borrow one for a bit of testing.

BlueSprite

the PFC will ignore the knock sensor ?? how come the PFC can read the knock on the monitor

I didnt 100% know how to operate the PFC, thx for your info.

Mahjik

iTrader: (1)

It displays the Knock Reading, but that's it. It doesn't retard anything based off the information from the reading.

Booztd 3

Haha, think again

I know NO ONE that has anything available

fastcarfreak

I idle at 11.5 to 1 AFR if that makes you feel any better. That seems to be where my car wants to idle.

Adam

Booztd 3

Are you puffing a considerable amount of black smoke though?

DaleClark

iTrader: (55)

I would definitely fix the knock sensor code - if nothing else, just get a used one from someone on the forum, should be cheap to get one. Check that the wiring is connected, and that it isn't frayed and damaged. I doubt the knock sensor code is causing those problems, and no you can't really have detonation at idle, load and temps just aren't there.

As far as running rich, you could also have a problem with the injectors, like a pinched injector O-ring that's allowing fuel to squirt around the injector and into the engine. It's hard to diagnose that problem, but I've seen it happen. It's one drawback of side feed injectors.

I would also double-check the vacuum line to the boost/MAP sensor on the firewall. Make sure the vacuum line is hooked up, and make sure the in-line filter in there wasn't replaced with a check valve - it has to be a one-way filter. If that vacuum line is off, the car will run like bigtime crap, and you won't get a code for that, as electronically everything is fine.

Dale

Mahjik

iTrader: (1)

There isn't another FD owner in your area?