2nd to neutral = cut out

[maldotcom2]

I've got a VS which i just converted to manual, it generally drives fine. But when i'm slowing down at the lights and i downshift through the gears to 2nd, then as i hit the clutch and pull it into neutral it'll cut out as i brake to a stop. Not like a normal stall, but the revs just fall to zero. If i pull it into neutral from 3rd or above and brake to a stop it's fine.

I'm using a chip programmed for manual, it doesn't do this with an auto chip, but of course it has a constant engine light.

[maldotcom2]

Anyone got a theory?

I've revised the problem, it's basically 2nd or 3rd into neutral, the revs will just gradually drop to zero as i slow down, UNLESS i blip the throttle when in neutral before it would cutout. Doing this causes the engine to splutter a bit like it's running rich, but it won't cut out.

It's also throwing an engine light after say 10 minutes of driving, not after any particular action but just driving along. I'm yet to get an error code out of it though.

[hako]

Maybe the IAC sticky as that should correct the idle to stop it stalling.....maybe it's overfuelling as you go down thru the gears when in theory there should be no fuel going to the injectors...what about the MAF fouled with oil if you run a K&N airfilter.

[maldotcom2]

Thanks mate i'll try cleaning the MAF and IAC. Anything particular i shouldn't use to clean the IAC?

[muttley383]

Are you still running the auto pcm?
I would say that you have not got the correct speed signal going to the pcm.

[maldotcom2]

All the auto stuff is still there (auto computer if thats what you mean), and it ran fine with the auto memcal/eprom but it threw an engine light. So this is undesirable.

I put in a memcal/eprom designed to turn off the "oh shit no auto box" error codes, and it did, but now i have this problem. After a short distance it throws an engine light too, but when i check for codes i just get code 12.

Worth getting a new IAC?

[hako]

Don't clean the IAC with anything that leaves a residue....carby cleaner is fine and make sure no crud gets into the plunger when cleaning/spraying. Petrol can also be used but takes a bit longer. Also check the distance between the tip of the pintle and the flange - it must be no more than 28mm.

[muttley383]

How did you allow for the different type of speed input signals from auto to manual transmissions?
The 2 wire auto speed sender unit outputs an inductive pulse at 10x the frequency of the manual 3 wire trans hall effect sender unit. If nothing was done other than wiring changes then I would say that your computer is not registering any road speed input.
If no road speed is realised then this is the reason for the engine stalling when coming to a halt.

[delcowizzid]

its fead into the second input for VSS on the ecu theres a pin for both types of sensor

[maldotcom2]

It's picking up road speed because all my instruments are working correctly.

[delcowizzid]

hey mal seems theres a few versions of the 672 ecu not all accept the VSS going in that pin so the ecu can read speed so ide say you arnt actually supplying the ecu any pulses thats why its stalling sometimes and will be why it uses a little fuel check the barcode on the pink ECU plugs for the numbers .
There are 8 different model VS computers which makes the VS interesting, read pain in the A...
The 16210672 has several versions
The numbers that count are the bar code no. on the pink plugs
The 0672 super 6 pcm is numbered 3380xL xxxxxxxxxx (x means varies ie any number)
The 0672 T5 manual pcm is numbered 6760xMxxxxxxxx
The 0672 and 9728 normal auto is 997xxMxxxxx Very common usually 99714 or 5
The 9728 getrag manual pcm is 99700Lxxxxx
RF police/taxi . This one is fully populated as is the Service Replacement 0672 so these are the best 2 to score.
When GM released the VT they had realised the nightmare they had caused and made all VT pcm's fully populated, meaning (apart from all being the same) it was a costly exercise leaving out some of the 2 cent items that werent required in certain applications.

[maldotcom2]

Interesting. I'll check it out this arvo and post back. Cheers.

[Chris E]

Sorry to go off topic, but I was wondering how you got your speedo to work? I'm doing the conversion on my vr and this is one of the last things I need to do. Thanks for your help

[delcowizzid]

you grab switched 12 volts out the old auto harness under the car and connect it to the red wire on the VSS and earth the black wire on the vss then the purple wire feed that to the ecu you can use one of the auto shift solinoid wires to save running a new one and it connects to pin C12 along with the wire thats allready there that goes to the speedo

[delcowizzid]

thats for VR only too vs is different

[VSEXEC]

with the vs the speed sensor is the purple and white wire that you tap into and then run it to the sensor on the t5 aswell as power and ground is this correct? as this is how i was told and how i have run it

[delcowizzid]

with VS you take the violet and white wire out of pin C5 which is the feed to the dash for speedo and connect it into pin D2 along with the purple wire from the VSS.if you have the right model ecu from tyhe list above the ecu will see speedo as well as the dash will work if you have the wrong ecu only the dash will work the ecu wont see the vehicle is moving

[Chris E]

Awesome thanks heaps delco, will get on to that right away.

Just one question, since I've got only a basic grip of electronics, by switched 12 volts that just means a feed wire doesn't it? A positive 12v wire? I'm guessing that because the others are earth and signal.

Thanks again

[delcowizzid]

yeah meaning switched on when ignition comes on which the solinoid power wire will do or the torque convertor lockup they are all in the round plug on the harness for the auto