Ignition timing etc

[sphs2]

Hi everyone, after the trials of sorting my car and getting through the MoT, i am now trying to set it up as best i can, on trying to set the timing the heath book quotes both 12 and 8 degrees bdtc. Which is correct? and is there any other tips on setting it up?.

[ketvrin]

Look here... go to the datasheets on the LH Side menu for your car

http://www.tvrsseries.com/

K

[sphs2]

cheers, i have tried to get it to 12 but it runs like a bag of nails, it seems to run best around 6 to 8.

Because of the other things the engine is up to i think there is some sort of fault.

[ketvrin]

What fuel are you using 95 Ron UL or 97 Ron Super Unleaded ? it makes a difference...

theres also a process for resetting your ECU before you set your timing - I cant remember the exact process but you need to put your ECU in Reset mode before doing the timing... I'm sure TVRGIT covered this in his diary, but do a search on ignition timing and I'm sure you will find something...

good luck

K

[Barkychoc]

sphs2 said:

cheers, i have tried to get it to 12 but it runs like a bag of nails, it seems to run best around 6 to 8.

Because of the other things the engine is up to i think there is some sort of fault.

Is 12 degrees OK for unleaded or is that for leaded fuel?
(worth getting a ford sierra V6 Haynes manual if you don't have one, I haven't got one so can't tell you)

If it runs better with the timing retarded slightly then I'd go with that.

Chris

[sphs2]

i have been using super 97 octane, i will try and find out about the ecu.

simon

[sphs2]

The scorpio book says 12 degrees btdc for all 2.9 engines running 97 fuel and no cat.

All ican see about the ECU is the adjustment wires:

Blue for 6 dergree retard
red for 3 degree retard
yellow for 50 rpm idle movement.

[tvrgit]

Part of yur problem may be that one of the variables that the ECU changes to meet fuelling, engine load etc requirements, is the ignition timing. So as you are altering the timing, the ECU is trying to alter it back (at idle) so the setting you end up with using your strobe light, is actually miles out.

Before you adjust it, you need to put the engine into "limp home" mode so that the ECU is using fixed mapping. You are supposed to do thus using a code reader connected to the diagnostic socket, but you can also do it by disconnecting the idle speed control valve - the engine goes into "limp home".

Then you adjust your timing as per the book.

Then you reconnect the valve.

Haven't tried this on the TVR but it worked on a 1990 2.9 Granada that I had years ago.

[sphs2]

Thanks for that i will try it tommorrow, i am sure this has alot to do with my running problems.

simon

[Jed-S]

The setting also depends on which ECU you have - one was mapped for 97 (or was leaded 98?)RON and the later one for 95RON unleaded. If you have the earlier one and you run it on 95RON then you'll need about 8 degrees BTDC and the later one can be set to 12 degrees - which is what I run. If you only use 97RON then you should be ok with 12 and 15 degrees respectively.

The older ECU is part numer 86GB 12A650AC and the newer one is 88BB 12A650JA.

Jed

[sphs2]

Thanks everyone, unplugged the idle control valve and set 12 degrees no problem.

simon