3200GT Oversensitive throttle adjustment

3200GT Oversensitive throttle adjustment

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Nigelo

Original Poster:

293 posts

234 months

Wednesday 9th February 2005
quotequote all
.. from the comfort of the drivers seat but do read very carefully. If you are not sure of what you are doing, leave it to someone who does!

1) Reset the mechanical zero position
- Put gear lever in neutral
- Switch on ignition (to MAR position) but do NOT start the engine
- Do not touch the throttle pedal for 2 minutes
- Switch off ignition

2) Reset the mechanical Full Throttle position
- Put gear lever in neutral
- Switch on ignition (to MAR position) but do NOT start the engine
- Fully depress throttle pedal and hold for 5 seconds
- Release throttle pedal completely
- Switch off ignition

The full text does not specify waiting until the various warning lights have extinguished themselves after switching on ignition, but I do not depress throttle (item 2) or start timing until they have.

Hope this helps

Source: Offical Factory Workshop Manual (Engine) page 96 of the Fuel supply section.

Nigelo

Original Poster:

293 posts

234 months

Wednesday 9th February 2005
quotequote all
bad loser said:
At a guess number 1 sets the minimum throttle (tickover) number 2 sets the maximum.



That's correct. The no throttle setting (tickover or lower value) is 350/650mv whilst full throttle (upper value) is typically 3,100/3,300mv.

Apparently, the management system strategy gradually reduces the full throttle value by 5mv (for the next switch-on) every time the ignition is turned on (whether engine started or not) UNLESS full throttle is applied for 5 seconds at least once in that cycle (eg climbing a steep hill with full throttle etc). Therefore, under certain circumstances, the full throttle setting will gradually reduce leading to over sensitivity at the pedal. The manual reset procedure restores the upper and lower values to their default design settings.

>> Edited by Nigelo on Wednesday 9th February 10:09

Nigelo

Original Poster:

293 posts

234 months

Saturday 23rd July 2005
quotequote all
Bad loser

I assume that Greypaul used an SD2 / SD3 tester to diagnose the problem - If so, be very careful. The potentiometer needs dual circuitry to operate as a failsafe and in fact is a dual unit itself. You are therefore totally relying on the electronics (with a known problem) to flag an error and perform a power shutdown - Therefore strongly suggest you avoid anything more than the lightest of throttle at any time until fixed. There is potential, however unlikely, for throttle to stick open with disasterous consequences.

That said, if Dealer did not use an SD2/3 why not and how did they do the diag checks. Greypaul have a good reputation but always be wary of (expensive) part replacement on a suck-it-and-see basis.

HTH

nigelo

Original Poster:

293 posts

234 months

Sunday 24th July 2005
quotequote all
Vulcan

Lancs are my nearest and as good as any. I know the plastic conduit to which you refer and is actually split along its length to allow the wires to be inserted easily. Problems occur when moisture enters.

Bad Loser

Sensible approach and judging from GP's request to retest, Maser UK have probably requested just that. FWIW, there have been some odd symptoms recently on some 3200s where insufficient earthing has been the cause. Would be interested to know the final diag + cure even though under warranty.

Take care