BAWC Forums

Here is my problem, and I'm STUMPED.

I finished my TT conversion, car ran great though would every so often throw a CEL 36. So I swapped out my PTU, which then caused a cylinder not to fire and threw a CEL 44 "ignition coil 1-4".

Being that the new PTU seemed to make it worse, I swapped back to the old one. No change. So I got a new coil pack. No change. Swapped between PTU's again, No change.

So, here is where I currently sit.

Replaced Coil Pack,
Replaced PTU,
new plugs,
CEL 36,
and getting a constant 9 knock count

My plans right now, check to make sure my coil wires are firing. If so, go ahead and do plugs again. If not there; start checking fuel. Though with how rich she is running, I'm pretty sure the is plenty of fuel going unburned.

other info to consider: '92 fed spec TT ECU, '95 N/A harness with hard wired front and rear O2 sensors and resisters wired into the fuel injectors.


Please Help, I'm running out of ideas and things to search for on Stealth316 haha.

-John

Do you have the black ground wire by the battery hooked up? It's supposed to share the same 10mm bolt as the negative battery wire on the firewall. Bolt is labled with an "E".

Does your ECU have leaky caps?

Your timing is going to be a few degress off (can't remember the exact number) because you used a 92 TT ecu with the later style CAS and crank sensors which is programed for the older style CAS latency. Might I suggest you try and find a 93 TT ECU from a buddy to swap in and see if the issues stop.

[quote=""Monochrome""]
Does your ECU have leaky caps?[/quote]



With weird shit like that going on the ECU should always be one of the first things to check.

Terry

[quote=""Monochrome""]Do you have the black ground wire by the battery hooked up? It's supposed to share the same 10mm bolt as the negative battery wire on the firewall. Bolt is labled with an "E".[/quote]

If that is the ground wire that connects to the fire wall near the windshield wiper motor, then yes.

[quote=""Monochrome""]
Does your ECU have leaky caps?[/quote]
[quote=""Terry""]
With weird shit like that going on the ECU should always be one of the first things to check.
[/quote]

I have checked my ECU a couple of times. I'm assuming that if the capacitors were leaking that there would be noticeable white corrosion on them, correct?

[quote=""Monochrome""]Your timing is going to be a few degress off (can't remember the exact number) because you used a 92 TT ecu with the later style CAS and crank sensors which is programed for the older style CAS latency. Might I suggest you try and find a 93 TT ECU from a buddy to swap in and see if the issues stop.[/quote]

There are a coupld of others running correctly with a '92 TT ECU and a hybrid N/A harness. but you never know, mine could be the weird one that doesn't run right. It is worth a shot.

I just wish there were owners that lived closer buy.

-John

Recheck all your wiring, im sure it's the source of the problem

[quote=""jackhammer""]Recheck all your wiring, im sure it's the source of the problem[/quote]

Do you think it could be the resistors in the injector harness?? That might explain why she ran great for over a week.







Here is some questions and answers from my local car forum. Non of them own a 3S, but still it may have some questions that you may have with my answers.

[quote=""turbodragnovice""]you could have one injector not firing and still have a rich o2?[/quote]

Not sure probably could. Since it would make that bank a leaner so the ECU would correct it by throwing more fuel at it.

[quote=""mschmoyer""]Could you pull the injectors and see if they are spraying fuel? [/quote]

With the datalogger I can test the injectors, as I turn them on and off there is a noticeable difference in the engine. So I THINK they are all working. But the key word there is think.

[quote=""mschmoyer""]
Then check the plugs and check if they're getting spark? There are ways to check both of those. My dad and I pulled a spark plug out and watched it spark to see if it worked =).[/quote]

I hadn't thought of taking it out while they were firing haha. Could be a fun light show. I am going to borrow Jeremy's timer tomorrow, or at least try to. Then I will know for sure if the coils and the coil wires are working. Then I will have to check the spark plugs.

[quote=""Clay""]Man John, I'm sorry all this crap is happening to you. Must be so frustrating![/quote]

It is, I know it will be worth it in the end, I just miss driving her. Y'all should hear her right now, she sounds so off with the missfireing, but also makes her sound kinda evil.

STarted her up today with just the downpipe on, made me jump! :roflol:

Chris sent me a good question filled PM, I'll post it here to get more info and hopefully more ideas.

tickwon wrote: John,
About your knock...crazy idea, just humor me...nothing is resting against your block that would cause any major vibrations, right? I don't think so, but I would just check to make sure. Something as simple as that would make it knock at odd times. Case in point...this one guy ran a 3" exhaust pipe and it would hit the transmission kinda hard under torque, then causing the motor to knock. Some knock sensor are pretty sensitive. Just an idea there I heard from someone else.

I don't think so, but I wouldn't rule it out. Though, I think the constant knock is more from the engine misfires, it could be picking that up.

tickwon wrote: How's your injectors firing? Did you get to listen to them? Are these new or used injectors?

I believe they are firing properly. Used the datalogger to test them individually and there seemed to be a noticeable change when each was turned off. The injectors are used, and I didn't have them flow tested prior to installing them, they have all new O-rings on them.

tickwon wrote: Remind me again CEL 36, what is that?

CHeck Engine Light code 36 is "Ignition Timing Adjustment Signal"

tickwon wrote: What EGT reading?

around 800 degrees fahrenheit at idle, which is right at ideal.

tickwon wrote: What ideas did Jeremy throw at you?

he course of action I am taking is based off of his idea. First find out if it is somewhere in the ignition system. Once we have eliminated all possibilities there. Start to tackle the fuel system.

tickwon wrote: What the wideband reading...is it reading accurate. I remember it would read and then go blank...looking like this: -- and then the numbers would show up...I don't have a wideband so is that normal? I know a lot of questions, but if you can answer them, they might help...if I can. Good Luck. I know brother it's frustrating...the Gremlins are coming out. I hope it nothing electrical...that's beyond my head.

It was reading a bit richer than it should be at the RPMS and throttle I was doing while driving. The "--" is normal for when coming off the throttle as the ECU pulls fuel so it goes off the map lean and/or not enough to get a reading.

Jeremy's behaves the same way.

Thanks guys, please keep the ideas coming.

-John

[quote=""J-Groove""]Do you think it could be the resistors in the injector harness?? That might explain why she ran great for over a week.[/quote]Like radio shack resistors, or the oem tt resistor pack?

[quote=""jackhammer""]Like radio shack resistors, or the oem tt resistor pack?[/quote]

Like radio Shack style.



I bought them from 3SX, here is the link.

http://www.3sx.com/store/comersus_viewI ... duct=24271

-John

They should probably be ok, but i would check the resistance anyway.

I wish i wouldnt have included my paper manuals in the liquidation of my mitsu stuff , going through the cd comparing wiring diagrams is a PITA

Hot dayumn. Parts Express sells those resistors for under $1 each.

[quote=""J-Groove""]There are a coupld of others running correctly with a '92 TT ECU and a hybrid N/A harness. but you never know, mine could be the weird one that doesn't run right. It is worth a shot. [/quote]

I didn't do a very good job explaining my reasoning for needing the 93 ECU and I don't know enough details about the "others" to comment.

http://www.stealth316.com/2-cas_conversion.htm

Basically, I believe your issues come from the Hall CAS and crank sensors on your car are reading timing faster than what the ECU is programmed for.

If you use the 92 ECU with the later style CAS and crank sensors, it will see 4 degrees LESS timing than what is actually there. The issue comes from the 91/92 style photosensor having a greater latency than the hall ones so the Japs engineered the 92 ECU to compensate for this latency.

Thus, what's going on is the spark plug is firing 4 degrees SOONER than what the ECU is supposed to see. Air go your knock AND your timing mis-fire code.

Humor me on this. Find a 93 VR4 ECU and plug it in. I'd be willing to bet everything will be fine (assuming your wiring is good).

I'll humor you, I currently have three threads, one in General, DFW, and SouthWest forums seeing if I can borrow someones '93 fed spec TT ECU.

Wish me luck. Hahaha, I just want to drive my car, well, she is drivable now, but I want to drive her without being stupid.

-John

John, I can't really provide any technical help on your problem as I've been out of the loop for far too long. But I hope you get her fixed quickly.

I just told the guy with the ECU to not send it. Here is a possible fix that fits what my car is bitching about.

I'm going to have some fun with wires today. haha.

Gray Haze wrote:Pasted here for archives.

The knock sensor is just bad. Replace it.

BUT before you go replace the ECU, heres what I'd like for you to do.

Pop the hood, passanger side strut tower, see that brown connector, make sure NOTHING is plugged into it. If there is not anything plugged in to that BROWN connector, then get ready.

ready to fix your issues?

Basically, IF you've got a code 36 that means the ignition adjustment terminal under the hood is some how grounded out. If there is nothing plugged in to it, chances are you have developed a short in the EFI harness. Starting to become an issue as ive seen broken wires on a few cars now, go figure.

If that short is there, then code 36 will go active. So by cutting the wire, and adding a insulated male/female spade connector on each end of the wire, you will keep the functionality of said wire/connector, but when unplugged, the light will extinguish.

This terminal is used to ground out to set base timing, with a datalogger connected, and the terminal grounded, it will allow you to raise the target idle.



Unplug ECU.
Pin 104 *remember to look at the connectors from the side in which the wires come out*

Get about half way down that wire, cut it, use insulated spade connectors so that you may re connect it at a later date if needed.

I have a STRONG feeling Shorted out PTU Channel 3, Ignition Timing Adjustment, and our Fuel pumps are all going to start becoming a VERY common thing in the near future.

Fixes;

Un Wrap electrical Harness; Remove PTU wires and Coil Wires, Splice the black w/ white strip and blue with yellow stripe together and delete the two that used to run back up the harness. Then the PTU to coil wiring will be the same for all 3 channels.

Ignition adjustment terminal; Use aformentioned method above to fix the ignition timing adjustment issue

Fuel Pump 12V+ Supply; This is where shits gonna start getting dangerous, and problly start blowing fuses left and right, and could lead to fire down the road....

Strip back the entire harness, and remove this spare damn wire from it. One less wire carrying 12V+ running loose in the engine bay just waiting to plague someone with problems.

Its starting to become a TREND i belive with the wires up there in the diagnostic bundle, like to short out.

grtn316 wrote: Then again, like I mentioned earlier there are probably a few things wired incorrectly. If the guy that did the wiring for him messed up the o2 sensors then I would be surprised if that was his only goof.

Chase actually didn't mess up the O2 sensor wiring, there is a typo in the Stealth factory service manual. I go off on it a little in my thread "My quest to FI" haha.

Gray Haze wrote: Pop the hood, passanger side strut tower, see that brown connector, make sure NOTHING is plugged into it. If there is not anything plugged in to that BROWN connector, then get ready.

Okay, WTF!?!? I went out there today, found the brown connector by the passenger side strut tower and unpluged this from it.





I then started the car, she ran great! No missfire, no hesitation, no ruff idle, no knock. Timing was at 17%. Both O2 sensors were cycling properly.

I want to drive her, but I apparently hit a heater hose or something along those lines while messing around with the PTU and coil packs over and over and am leaking a good amount of coolant when the car is on. So I need to fix that before I drive her and really find out if that brown plug truly fixed my problems.

Tiffany and I are going out today, but I might be able to work on the car later on today.

I still can't believe what happened.

So, is this brown cap a ground of sorts??

I'll keep everyone updated if this really fixed the problem or not as I know more.

But please, discuss the evil brown plug.

-John

Thats just a cap with no metal connection in it at all. If that fixes yur probem i may have to stop being athiest

Well John, I hope that fixes it for ya!

You should come up to DFW with Tiff and hang out if you have time (you know, if you need an excuse, just say you guys are visiting her parents)

[quote=""J-Groove""]So, is this brown cap a ground of sorts??

I'll keep everyone updated if this really fixed the problem or not as I know more.

But please, discuss the evil brown plug. [/quote]

There you go. Mystery solved.

That brown plug is the cap for the timing connector that Grey Haze was talking about.

When the plug is grounded it sets the ECU into mode where you can set the timing manually and the idle. You're not supposed to adjust the BISS screw without first grounding that little plug.


Oh and nice legs.

come on, you know you want to believe in God, just don't take the bible word for word, it was rewritten by to many men in power over the ages.

Haha, well the plug fixed it, but only probably because it moved the wire just enough.

I'm going to do as Grayson suggested and splice it at pin 104 on the ECU.

I'll be able to work on the car tomorrow while Tiffany is at work.

Trent, are you going to be in the DFW area next week?

Yes, I like Tiffany's legs.

-John

[quote=""J-Groove""]Trent, are you going to be in the DFW area next week?

-John[/quote]
Yep I'll be in DFW from 03/16 - 03/24. It would be sweet if you could come up.