[Blaize]

Right, the plot thickens. Spoke to JDS Porsche and he gave me typical vac figures at the fuel dampner. He says 24 inches of mercury, I have 22. Close enough. I have taken off the plenum, throttle body, and the trottle body to MAF tube and thourougly cleaned all of it. T-body was filthy and no doubt not helping any of this. Very closely inspected all the vac hoses and fittings and replaced a few iffy parts, but nothing that was screaming out as being the problem. Also fitted a new crank posit sensor as it was cheap enough and seems to be a common fault. cleaned all the grounds in the engine bay, the two on the left rocker cover and one down the front of the engine on the right (of the car, left when viewing). I've confirmed with the customer that the injectors were recently rebiult/cleaned. about a year ago. sent the MAF off to JDS to be checked, he said it was ok, he recalibrated it (for free no less, damn good people over there) so I know its ok. I have checked the condition of the cog belt in the dizzy, looks fine, very little wear at all. I've been over the engine wiring harness with a fine tooth comb paying particular attention the the injector wiring, and while it has a few past repairs, nothing that looks like it could be a fault. Where it has been fixed in the past (2 places) I have tested it for contunuity while wiggling it and its all ok.

So took it for a test drive again today having just put it all back together and the problem persists. However, there is a new clue. I have found that the speedometer is reacting to the throttle. At a steady very light throttle cruise the speedo works as it should, as soon as any attemt to accelerate is made, and I mean just a bit, or floored, the speedo drops off by 10-15 percent and twitches around down there, release the throttle back to cruise, and it snaps right back to where it should be and stays there, nice and steady. This indicates to me thqat all of this is going to come down to an elec problem either in the CE board or the ECU itself. JDS is willing to test the ecu for a nominal fee so I am going to mail it up to him purely to eliminate it as a possible problem, and then sink my teeth into the CE board. The customer tells me that he has been thru all the fuse contacts and relay plugs with a dremel prior to bringing the car in to me, and I trust him to have done a good job, however he also tells me that this thing is a bit of a mess in there as it has had various phone kits, alarms, and a towbar (!?!) thru the years.

So thats where we stand and thats how I am going to attack it. Ill post here when I finally find the fault so the next guy may get an answer a bit quicker, and as always if any of you have seen this before feel free to chime in with advice.