satch

iTrader: (1)

I would disconnect both connectors (2 pin and 4 pin).

3vil

iTrader: (4)

ok, lemme go try that now.

disconnected both plugs, nothing changed except that the tach stopped responding.

satch

iTrader: (1)

When you did the transmission swap was there a ground wire bolted to the previous housing?

3vil

iTrader: (4)

yes. i cleaned it up some and re attached it. it goes from the trans bell housing to the passenger side tower. and the cable is thick, like 2ga batt cable or something.

3vil

iTrader: (4)

ok so i checked the voltage of the ECU pins. and here are the the ones that were out of spec according to my FSM...

• 1M "Coil with Igniter (trailing) IGf-T" read 12.02v supposed to be below 2.0v
• 1X "Coil with Igniter (trailing) IGT-T (ignition timing signal)" read 0.14v supposed to be 0v
• 2C "Ground" read 0.05v supposed to be 0v
• 2I "Water Thermo Sensor" read 2.63v supposed to be 0.4-1.8v (but my car is completely cold)
• 2R "Ground" read 0.05v supposed to be 0v
• 3A "Ground" read 0.05v supposed to be 0v
• 3G "Ground" read 0.05v supposed to be 0v

so sign are pointing towards a bad trailing coil, but i keep hearing that the car should run on the leading coil alone. also, it is bad that all my grounds to the ECU show a slight amount of voltage?

satch

iTrader: (1)

As far as pin 1M is concerned the coil/igniter must be bolted to the fender properly for the igniter to be grounded. Without the ground pin 1M would read 12 volts so make sure it is grounded properly. Also, make sure the 4 wire connector at the trailing coil is plugged in.

Might be wrong but a .05 reading on the ground wires seems negligible.

Pin 2I, Water Thermosensor, should read 2 to 3 volts when engine coolant is cold.

blackrotary23

check the voltage on the trailing coil where the - and + wires bolt up. take off the covers that read T1 an T2. check each one individually. they should read between 0.2 - 1.0 ohms. if it is less or more, replace the coil. the leading coil should read in the same range as well.

3vil

iTrader: (4)

did you mean to say check both voltage and resistance at the connections under the T1 & T2 covers? i'll do it tomorrow, but i just never heard of checking voltage at that location.

satch

iTrader: (1)

I think he meant to say "ohms" on both accounts. Also, I believe pin 1M is an input signal so if the coil is properly grounded and it reads 12 volts then something is wrong with the coil.

blackrotary23

yes, i did mean ohms. but still, it should be in the range of 0.2- 1.0 ohms on both coils.

3vil

iTrader: (4)

ok i'll double check the grounding of the coil and the voltage on 1M in the morning.

and at the bottom of post #22 i mention that the voltage of coil T1 is 1.0Ω and T2 is 0.9Ω

blackrotary23

look, this is an easy fix. i have done this probably a hundred times before. if there is no spark on the leading coil but your rpms are working, then the coil itself is fried. probably has something to do with a bad ground from the tranny swap. something didnt get tightened down all the way or you missed something completely. CHECK EVERYTHING before you put in a new coil pack.

if the new pack does not work, then you fried the ecu.

3vil

iTrader: (4)

The leading coil fires just fine according to my timing light. i'm in the process of finding a working trailing pack in my price range.

fcrotory

iTrader: (20)

If ur tack works then the ignighter on trailing side is working. I drove my car for almost a yr with no trailing coils.(no tack either) I had help from RB and fixed the problem. Bad ignighter. So u won't notice much of a difference without them. I was told there more of an immision thing. Help burn off excess fuel and what not. I would double check everything like blackrotary says.

blackrotary23

$40 shipped for trailing coil. pm me if interested.

3vil

iTrader: (4)

thanks for the offer man but i'm tapped due to the holidays. this project just might have to wait until after new years.

satch

iTrader: (1)

For now, focus on the root cause whatever that might be, for the culprit is not the trailing coil.

3vil

iTrader: (4)

i hear ya on the satch, i'm just running out of ideas here. my next step is to check the continuity of the AFM harness, make sure there are no broken wires. other then that i'm kind of hitting a brick wall.

satch

iTrader: (1)

Did you remove the starter to change out the transmission?

3vil

iTrader: (4)

yes i did

fcrotory

iTrader: (20)

It wasn't an auto to 5 speed swap was it??

3vil

iTrader: (4)

no, the syncro for 2nd-3rd was getting really bad, and i found a forum member near me who doing a part out and letting his go cheap. it was a straight forward s4 5speed change out. i replaced the front and rear oil seals on it, new shifter bushing and return spring, and reused my electronics on the new trans. also rebuilt the master and slave while the trans was out and picked up a steel slave line.

satch

iTrader: (1)

If you haven't tried it then jumper the fuel check connector and w/key to on check for voltage at the the connector where the rear harness connects to the fuel pump harness on the fuel pump side of the connector.

Also, you might want to bypass the fuel cut unit you have currently installed.

With respect to the removal of the starter are you 100% sure you reconnected the wires to it exactly as before the removal when it comes to the wire(s) related to grounding?

blackrotary23

did you make sure that the ground wires from the engine harness are ALL bolted down?

3vil

iTrader: (4)

i did the jump and voltage check on tuesday. i was getting roughly 11.5v on both sides if the fuel pump plug (the one on the rear shock tower) as for the fuel cut switch, i can bypass it just to eliminate it as a possible candidate for problems. i will double check the starter wiring tomorrow, but if memory serves my correctly i did the + to the starter post (only removed the nut on the +post, not the one below it) the harness was connected, and the ground was done between the very long starter to engine bolt and the starter. again, i will jack up the car and double check this tomorrow (weather permitting)


i have made sure the ground that goes from the harness to the top of the block is clean and tight, as well as the one that goes to the d/s front shock tower. are there any others i am forgetting?

on a side note, i was thinking today. is it possible to put an exhaust gasket on the wrong way? i know that the flange on the racing beat stuff will not allow you tighten all 6 bolts down if you put the gasket on backwards, but what about the engine block side? is it possible to put an engine exhaust gasket on the wrong way and have it impede flow, similar to what a clogged cat would do?