Discussion
What a bu99er of a day! 
The morning started with me removing one of my carbs to replace the main body as I discovered that one of the butterflies was worn/damaged and it was impossible to balance the setup. I had acquired a couple of second hand 40 DCNFs and proceeded to strip one down and then swapped all the jets & sundry good bits from my existing carb, and then refitted to the car. Going well I thought, all I have to do now is fire her up, balance and away we go. Wrong-oh!
De-immobilise, turn key, crank crank backfire stop
No little chirp from immobiliser immobilising - Ah Ha - I know what that is - its done it before - bad connection under the centre console. On the two previous occasions this has happened, remove two rear screws, lift console, grope around, little chirp, all OK again - Not this time 
Remove radio, console, pull out wiring in passenger footwell, pull out wiring under steering column, pull out wiring behind dash, and start to check all the connectors for continuity. The inside of the car now looks like a plate of spaghetti! Stop, go make cup of tea, and get SH's 'bible' out. Try to identify wiring from circuit diagram - give up (my car has had two different alarm systems & immobilisers fitted at various times and there are more redundant wires and connectors than you would believe). Get the multimeter out, and start to check feeds to immobiliser - nothing! Try to find fuse - can't, so resort to pulling every fuse, testing and re-fitting. All fuses OK
Check earth wires on immobiliser and alarm by shorting to cigar lighter casing. Chirp! FOUND IT!!
The earth wires were terminated to a screw on the steering column adjacent to the indicator stalk, and there was no ground. Poked around but couldn't find out why (I assume there must be some sort of slip ring contact), so made up a new earth elsewhere. Spent the next hour refitting all the wires and rebuilding the interior of the car!
Great, now lets get on with the original job. Fire up, roughly balance, and set mixtures, and go off for a little run to warm her up before setting up finally. On the way back a Boxter attempts to demonstrate his superior acceleration, a display he sadly loses
until embarrasingly, we suddenly lose power, exhaust popping and banging, and the engine sounding decidedly odd 
Pull off into car park, and with some trepidation lift the bonnet. Immediately find problem, some idiot 
forgot to tighten the carb linkage nuts, and they slacked off through vibration, and we were running on one carb with the other two at idle! Note to self - don't do this again. 
All's well that ends well, but it completely wrote off the day!
Cheers
Graham
>>> Edited by gbgaffer on Sunday 16th March 19:40
>>> Edited by gbgaffer on Sunday 16th March 19:41
The morning started with me removing one of my carbs to replace the main body as I discovered that one of the butterflies was worn/damaged and it was impossible to balance the setup. I had acquired a couple of second hand 40 DCNFs and proceeded to strip one down and then swapped all the jets & sundry good bits from my existing carb, and then refitted to the car. Going well I thought, all I have to do now is fire her up, balance and away we go. Wrong-oh! De-immobilise, turn key, crank crank backfire stop
No little chirp from immobiliser immobilising - Ah Ha - I know what that is - its done it before - bad connection under the centre console. On the two previous occasions this has happened, remove two rear screws, lift console, grope around, little chirp, all OK again - Not this time Remove radio, console, pull out wiring in passenger footwell, pull out wiring under steering column, pull out wiring behind dash, and start to check all the connectors for continuity. The inside of the car now looks like a plate of spaghetti! Stop, go make cup of tea, and get SH's 'bible' out. Try to identify wiring from circuit diagram - give up (my car has had two different alarm systems & immobilisers fitted at various times and there are more redundant wires and connectors than you would believe). Get the multimeter out, and start to check feeds to immobiliser - nothing! Try to find fuse - can't, so resort to pulling every fuse, testing and re-fitting. All fuses OK
Check earth wires on immobiliser and alarm by shorting to cigar lighter casing. Chirp! FOUND IT!!
The earth wires were terminated to a screw on the steering column adjacent to the indicator stalk, and there was no ground. Poked around but couldn't find out why (I assume there must be some sort of slip ring contact), so made up a new earth elsewhere. Spent the next hour refitting all the wires and rebuilding the interior of the car! Great, now lets get on with the original job. Fire up, roughly balance, and set mixtures, and go off for a little run to warm her up before setting up finally. On the way back a Boxter attempts to demonstrate his superior acceleration, a display he sadly loses
until embarrasingly, we suddenly lose power, exhaust popping and banging, and the engine sounding decidedly odd Pull off into car park, and with some trepidation lift the bonnet. Immediately find problem, some idiot forgot to tighten the carb linkage nuts, and they slacked off through vibration, and we were running on one carb with the other two at idle! Note to self - don't do this again. All's well that ends well
, but it completely wrote off the day! Cheers
Graham
>>> Edited by gbgaffer on Sunday 16th March 19:40
>>> Edited by gbgaffer on Sunday 16th March 19:41
. 
, if so let me know when, as I'd like to be there if poss. Hi Harry
Most of the fun was with the [expletive deleted] TVR wiring, the carb work didn't take much time, and was only really neccessary to clear a lumpy idle. The incident with the linkage is a sound reason to pay someone else to play with the thing!
Yes, I did phone EFI last week, but they were talking three weeks before they could even look at the car. I still want to get confirmation that the jets are sized OK as I feel that she's running a bit rich, so will try them again. Mind you I appear to be getting 23mpg running at motorway speeds, and I suspect thats probably not far off what it should be for the power o/p.
As to Fuel injection, you're probably right, however the carb setup is pushing out a few more bhp than the standard cosworth injection system provides, so will do me for a while. (I've just learnt that you get DCNF pattern throttle bodies if I want to go back to injection, but then I'd need a mappable ignition and and and.)
Cheers
Graham
Most of the fun was with the [expletive deleted] TVR wiring, the carb work didn't take much time, and was only really neccessary to clear a lumpy idle. The incident with the linkage is a sound reason to pay someone else to play with the thing!
Yes, I did phone EFI last week, but they were talking three weeks before they could even look at the car. I still want to get confirmation that the jets are sized OK as I feel that she's running a bit rich, so will try them again. Mind you I appear to be getting 23mpg running at motorway speeds, and I suspect thats probably not far off what it should be for the power o/p.
As to Fuel injection, you're probably right, however the carb setup is pushing out a few more bhp than the standard cosworth injection system provides, so will do me for a while. (I've just learnt that you get DCNF pattern throttle bodies if I want to go back to injection, but then I'd need a mappable ignition and and and.)
Cheers
Graham
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