Hotwire ECU Stepper motor connector ..
Discussion
I mentioned this on another thread as the little clip on the Gredge had become brittle and snapped. This proved to be a rare item to find but thanks to Paul (UKDJ) I have sourced a replacement. So if anyone needs one in the future use:
http://www.extraefi.co.uk/Misc_products.htm
Just scroll down to the bottom of the page
Chris
http://www.extraefi.co.uk/Misc_products.htm
Just scroll down to the bottom of the page
Chris
Edited by Jack Valiant on Sunday 11th January 18:02
Edited by Jack Valiant on Sunday 11th January 19:10
Thus stepper motor business confuses the hell out of me, I've not got one on my 5 ltr wedge and never had one when it was a 3.5. The only thing I did have was a spring loses valve fixed to the back of the plenum and connected by air pipes to the inlet just before the butterfly, my only gremlin seems to be on start up when I have to raise the idle for a minute or so until I can get tickler without cutting out. The offore mentioned valve I'm wondering may assist with cold start up, any advice please. I should mention that it wasn't connected electrically, worked purely on mechanicals, wooly.
It doesn't actually use any sensor in the induction side of things so probably not strictly as the term suggests, it sucks lots of air and drinks loadsa fuel but no airflow meter sensors or such to restrict, a super charger would be interesting however! It's fairly simple in what its got but the power is certainly there , could just be a little more refined at cold start up.
wooly350i said:
Thus stepper motor business confuses the hell out of me, I've not got one on my 5 ltr wedge and never had one when it was a 3.5. The only thing I did have was a spring loses valve fixed to the back of the plenum and connected by air pipes to the inlet just before the butterfly, my only gremlin seems to be on start up when I have to raise the idle for a minute or so until I can get tickler without cutting out. The offore mentioned valve I'm wondering may assist with cold start up, any advice please. I should mention that it wasn't connected electrically, worked purely on mechanicals, wooly.
Are you referring to a flapper or a hotwire?My understanding is that the stepper motor (hotwire) gives "closed loop" control over the idle speed. More important for a car with an autobox. TVRists can use clutch and throttle control to provide closed loop. A hotwire car will still idle on the "base" settings where a stepper motor isn't fitted.
wooly350i said:
I'm wondering may assist with cold start up, any advice please. I should mention that it wasn't connected electrically, worked purely on mechanicals, wooly.
Sounds like a flapper...The idle control valve really only applies when you de-accelerate..The EAV should be open to allow more air from cold along with extra fuel from the cold start injector...What is your base idle when warm....ZigaNot sure if you have the 4CU and flapper AFM or the full 14CUX and hotwire AFM on your car / set-up?
On the ex Griff 5 litre HC Serpentine engine I have in the Gredge the car will not idle without a stepper motor fitted / connected as I have special manifolds (bored out for the rearward facing setup and port sizes and lambdas fitted. I am running engine map 5 as the car has no cats so the ECU becomes confused in terms of fuelling. Running and returning to idle becomes impossible.
The plastic plug becoming brittle due to engine bay temps is a common fault, so for those using this system this is the plug (some 350SE - 390SE - later 400SE and 420 / 450SE'd used this system I believe?)
On the ex Griff 5 litre HC Serpentine engine I have in the Gredge the car will not idle without a stepper motor fitted / connected as I have special manifolds (bored out for the rearward facing setup and port sizes and lambdas fitted. I am running engine map 5 as the car has no cats so the ECU becomes confused in terms of fuelling. Running and returning to idle becomes impossible.
The plastic plug becoming brittle due to engine bay temps is a common fault, so for those using this system this is the plug (some 350SE - 390SE - later 400SE and 420 / 450SE'd used this system I believe?)
The 3.5 was originally a flapper but when we ditched that we ditched the 14 cu, now uses an aging DTA ecu and harness, as said previously we also ditched the airflow meter and its gubbins so now just unrestricted sucking and banging and blowing with associated map sensor, only issue bing tick over from start up. Oh it's pre serpentine as well. Fitted an adjustable fuel regulator last year pre getting it mapped on rollers.
Sounds good, I considered all options, MS, Emerald etc but decided I would go with the stock 14CUX and do the sensible cam/porting and induction mods do deliver real Bhp and torque improvements. I did fit a trigger wheel and sensor bracket just in case! Just need the last 15 horses to get thorough the 300 Bhp barrier! Target for 2015!
Hi John...Just wondering if you can... have fuelling maps been updated...Do you have the software for it?.....I guess now you have the adjustable FPR then it can be mapped accordingly..Which is probably what it needs...Cant beat a manual choke.....I remember having to use it on my mates mini to get home as the throttle cable snapped...It would certainly be interesting if you had to do it on a 5.0ltr V8....
Jack Valiant said:
The plastic plug becoming brittle due to engine bay temps
Couldn't you make a heatshield/jacket for the plug like the one for the AFM on the griff/chim ?I have an offcut of the engine bay heatshield stuff if you need some.
Regards
P
Edited by ukdj on Monday 12th January 17:09
mrzigazaga said:
Hi John...Just wondering if you can... have fuelling maps been updated...Do you have the software for it?.....I guess now you have the adjustable FPR then it can be mapped accordingly..Which is probably what it needs...Cant beat a manual choke.....I remember having to use it on my mates mini to get home as the throttle cable snapped...It would certainly be interesting if you had to do it on a 5.0ltr V8....
It got mapped last April Mark, sorted out the continuous over fuelling and timing and pulls like a,train now once he's warmed up, it's just whether or not the spring loaded valve on the back of the plenum which was removed might help during first couple of minutes.Oh it was converted to coil packs to do away with dizzy as well.
ukdj said:
Couldn't you make a heatshield/jacket for the plug like the one for the AFM on the griff/chim ?
I have an offcut of the engine bay heatshield stuff if you need some.
Regards
P
Hi Paul , sound like a good idea if you have a piece to suit. I did fit the AFM heat jacket mod to the car after the engine transplant. Likewise I am considering relocating the the K&N to the nose cone as I am aware that for some reason the hotwire AFM likes to see "tunnelled" air as you have in the Chim/Griff set up. After the 400 SE vented bonnet goes on we will see what difference iif any the cooler air flow has on the car Piccy of the prep on the bonnet ....I have an offcut of the engine bay heatshield stuff if you need some.
Regards
P
Edited by ukdj on Monday 12th January 17:09
Seems that there were 3 other previous colours so down to the gel coat!
Chris
Jack Valiant said:
Hi Paul , sound like a good idea if you have a piece to suit. I did fit the AFM heat jacket mod to the car after the engine transplant. Likewise I am considering relocating the the K&N to the nose cone as I am aware that for some reason the hotwire AFM likes to see "tunnelled" air as you have in the Chim/Griff set up. After the 400 SE vented bonnet goes on we will see what difference iif any the cooler air flow has on the car Piccy of the prep on the bonnet ....
Seems that there were 3 other previous colours so down to the gel coat!
Chris
Chris, was the bonnet an original with vents from a 400 se or have you added the vents yourself? I had a local ish guy fit my vents in my original bonnet off the car but we need to fettle the seaside vent a bit to get the curve right against the wing otherwise it's a gooden. Still not done a final colour yet, been thinking focus st orange but engineer john has beaten me to the orange .Seems that there were 3 other previous colours so down to the gel coat!
Chris
Paul, the next time we catch up would be good fella appreciate it ... I will owe you a breakfast at this rate.. thanks for your help 
The bonnet is an ex 400SE bonnet so was already fitted with the vents ... its been on the todo list for some time so may as well do it at the same time as the spray job. You cannot just put paint stripper onto glass, so its sand, sand and sand again to get it down to the gel coat and then put a number of coats of paint onto a good layer of primer and then clear it.
C
The bonnet is an ex 400SE bonnet so was already fitted with the vents ... its been on the todo list for some time so may as well do it at the same time as the spray job. You cannot just put paint stripper onto glass, so its sand, sand and sand again to get it down to the gel coat and then put a number of coats of paint onto a good layer of primer and then clear it.
C
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