New Coil - Tachometer Jumpy affecting TCU

[NissanGQ4.2]

Some things I can think of:

If the water temperature sender for the computer (not the dash gauge, there are two senders) is faulty or the wire is off or not making a good connection, then the torque converter lock up clutch will not work.
Check the connections near the battery where they come up from the automatic transmission.

Incorrect throttle sensor or inhibitor switch adjustment,

line pressure or engine RPM signal,
faulty revolution sensor or speed sensor,

lock-up solenoid,
fluid temperature sensor,
control valve assembly,
Torque converter itself


Not enough bourbon!

[Yendor]

Ok the TC was locking with original coil but sounds like there where problems 2 begin with

Yes I know, but I asked him that question directly and he said "the tacho and TC started playing up after he replaced the module and coil, before replacing the valve body".

[Yendor]

.4 to 2 ohms Primary & 6k to 16k ohms secondary

That's a big variance, I was expecting the lower end of that scale.

[patch697]

Yes I know, but I asked him that question directly and he said "the tacho and TC started playing up after he replaced the module and coil, before replacing the valve body".

Replaced the module with what exactly?

[Yendor]

Todd slow down, I can't post that fast.....ahahahahahha

I'm not sure if Scotty can get online at the moment.

[Yendor]

Replaced the module with what exactly?

Sorry I don't know what brand it was.

But I don't think that is the problem.

[patch697]

That's a big variance, I was expecting the lower end of that scale.

there not overly specific thought Rod.

In most cases you'd work on around 5K +/- 1k but mines 7.3k

Im surfing the net new trying to find out more.

[patch697]

Sorry I don't know what brand it was.

But I don't think that is the problem.

Don't be so sure...... It was in mine.

[Bigrig]

Okey dokey - here goes:

The coil died, put a second hand one on from another car (don't know brand and it was a stop gap whilst a new one and module were ordered). The problem started as soon as the coil was replaced - this was days before the valve body, the new coil and the new module.

The tacho is jumping all over the shop, but the revs aren't - the TC apparently takes some reading from the TCU that is sourced from the tacho and if outs out, the TC won't lock up.

The new coil (Crane Cams High Performance) got installed with a new module (standard Bosch replacement) at the same time I swapped the valve body over - problem still remained. Got to Sydney and that's when I first posted about it - spoke to Wholesale Automatica etc and went out today and got another coil with in built resistor (also tried a coil from an EB falcon to no avail). Put the new coil with resistor in and same problem although very marginally less jumpy.

The Crane coil comes in at 0.8 ohms resistance, and the one with the resistor measured 1.6 ohms ...

Currently still running the Crane Cams one and thinking of getting a standard GQ Patrol coil, but was trying to find out what resistance they are to compare to the ones I have ...

Thanks all - sorry for the sporadic responses - with family, not at home and relying on the occasional 3G connectivity as we travel to use tapatalk.

[Bigrig]

Don't be so sure...... It was in mine.

Problem is old mate - started before the module was replaced and it's a stock standard Bosch replacement.