Fingers crossed...
Discussion
Just had "the call"
few odds and sods like a ball joint and a tie bar bush so nothing major
Main issue is the fueling......massively over fueling......circa 2000 reading on emissions which is sapping power and effecting the running (vs the 500 limit for the MOT pass). The AFM has been opened at some point, so it stands a good chance it's knackered.
They are going to swap in a new normal AFM to see if that helps the fueling and call me back
The straight through exhaust is not helping the power as the lack of back pressure.........may lump for a silencer back in then sooner rather than later
Will keep you posted
few odds and sods like a ball joint and a tie bar bush so nothing major
Main issue is the fueling......massively over fueling......circa 2000 reading on emissions which is sapping power and effecting the running (vs the 500 limit for the MOT pass). The AFM has been opened at some point, so it stands a good chance it's knackered.
They are going to swap in a new normal AFM to see if that helps the fueling and call me back
The straight through exhaust is not helping the power as the lack of back pressure.........may lump for a silencer back in then sooner rather than later
Will keep you posted
adam quantrill said:
If it's just idle fuelling then that won't necessarily affect the rest of the rev range - as said above - it might be OK at reasonable throttle openings, and WOT is the most important for max power - it may well be spot on.
To adjust the idle CO you need to look at only the throttle gap on "shut", the bypass screw in the AFM, and the idle speed (and double-check the engine temperature sensor).
Easiest way to get it to pass is raise the idle to 1200 (you are allowed 1500) and then if needed adjust the bypass (allen key) to bring down the CO to 2% or maybe a little lower.
What you do after the MoT is your own affair....
Interesting, idle was set at 1200To adjust the idle CO you need to look at only the throttle gap on "shut", the bypass screw in the AFM, and the idle speed (and double-check the engine temperature sensor).
Easiest way to get it to pass is raise the idle to 1200 (you are allowed 1500) and then if needed adjust the bypass (allen key) to bring down the CO to 2% or maybe a little lower.
What you do after the MoT is your own affair....
Bobby Shaftoe said:
I would have presumed, being a TVR specialist, that David Geralds would have already tried to adjust the Idle CO AFM screw as part of the full service.
You can take the idle CO screw all the way out for maximum effect, i used to do it on L-jet equipped Pug 205 gti's to get them through the mot.
If it is the car i'm thinking of, the H234 camshaft it's running has a s
tload of overlap, making the emissions situation worse.
I bloody hell hope so lol You can take the idle CO screw all the way out for maximum effect, i used to do it on L-jet equipped Pug 205 gti's to get them through the mot.
If it is the car i'm thinking of, the H234 camshaft it's running has a s
tload of overlap, making the emissions situation worse.Edited by Bobby Shaftoe on Thursday 17th July 20:11
adam quantrill said:
1200 rpm already - in that case you might need some extra bypass. This can be achieved by trapping a small pipe - around 5mm-8mm dia - between the AFM and its outlet pipe. You can take it out after the test.
the plan was to get it all serviced / address and issues then get Mark Adams to set her up.....when I look through the cars history there are so many receipts about "look at poor running"when giving the old girl the beans she really does move so I feel its been set up back in the day for WOT type running vs pottering around / low revs etc
Bobby Shaftoe said:
Lol, ditto the above!
You've essentially got a semi race engine in there. The Kent H234 cam needs loads of timing at idle, which then reduces at low rpm and then piles back again, essentially a V-shaped timing curve- but a dizzy can't do that.
You also need a rich idle, but probably not as rich as you have at the moment, for comparison my idle was 13.7:1 afr and 792ppm Hydrocarbons for the mot (and i'vew since leaned it out), 2000ppm is insane.
I suspect you have a standard ecu with the fuel pressure turned up to provide ~300bhp's worth of fuel. The lucas 4cu ecu is not mapable so you'll probably need to live with a rich idle as a consequence. Try removing the idle CO screw completely first.
There are a few solutions if this is the case, the easiest being a rovertec adjustable ecu which has two adjustable pots, one sets cruise & idle mixture, the other sets WOT fuelling. I had one of these on my car and it's not a bad solution.
The best (but not easiest) option is fully mapable fuelling and ignition like emerald, omex, megasquirt ect. This isn't an easy route but probably cheaper and more effective than paying for mark adams' time. He won't be able to do a great deal with a stock ecu at any rate.
The third option is to put a milder cam in it, but that would be quite frankly the girly thing to do.
DG have spoken with Mark Adams now for adviceYou've essentially got a semi race engine in there. The Kent H234 cam needs loads of timing at idle, which then reduces at low rpm and then piles back again, essentially a V-shaped timing curve- but a dizzy can't do that.
You also need a rich idle, but probably not as rich as you have at the moment, for comparison my idle was 13.7:1 afr and 792ppm Hydrocarbons for the mot (and i'vew since leaned it out), 2000ppm is insane.
I suspect you have a standard ecu with the fuel pressure turned up to provide ~300bhp's worth of fuel. The lucas 4cu ecu is not mapable so you'll probably need to live with a rich idle as a consequence. Try removing the idle CO screw completely first.
There are a few solutions if this is the case, the easiest being a rovertec adjustable ecu which has two adjustable pots, one sets cruise & idle mixture, the other sets WOT fuelling. I had one of these on my car and it's not a bad solution.
The best (but not easiest) option is fully mapable fuelling and ignition like emerald, omex, megasquirt ect. This isn't an easy route but probably cheaper and more effective than paying for mark adams' time. He won't be able to do a great deal with a stock ecu at any rate.
The third option is to put a milder cam in it, but that would be quite frankly the girly thing to do.
Edited by Bobby Shaftoe on Thursday 17th July 23:37
Car is now all done but its my call on what to do ref the AFM etc........as a last ditch attempt they are putting in a new ECU and AFM to see what if anything that will do
Mark mentioned the original EUC can drift out given the age of the car if its original still.......one option is to send him the ECU an AFM to test them (not that expensive) but it means more time without the car
in short the car runs and goes well............just running rich
so I have time to noodle what direction to go in
NB1 I will not be stripping this, I love it
NB2 Defo keeping this cam, I like the high end power, suits my driving style
NB3 Both seat frames turned out to be goosed - another job to be fixed lol
mrzigazaga said:
Hi Glen...They do come up from time to time...There is a long number on the top of the black plastic, I believe that is a part number.
Also make sure they are the same AM....There are 2AM..3AM...5AM
Alternatively there are people who repair them...As i understand it they are tuned to the ECU in the car so using one from another is not always good.
Cheers....Ziga
that is also what I heard........the AFM is stickerless ie someones had it open beforeAlso make sure they are the same AM....There are 2AM..3AM...5AM
Alternatively there are people who repair them...As i understand it they are tuned to the ECU in the car so using one from another is not always good.
Cheers....Ziga
The "DG / Mark Adams" theory is = ECU has drifted out or is not 100%.........AFM was then bastardised to compensate.......meaning AFM is now in need repair also
Have left Mark a message as if he can test / repair both items then bingo :-)
What a great job DG have done with the 420, very pleased
Full on 12k service and all fluids changes and changed all the fuels lines for me plus a few bushes and ball joi Ta
Still got the AFM / ecu issue who h I knew about so waiting on mark Adams for a test and fix price then I recon she will be minty minty
The guys at DG were very impressed with the car, especially the chassis which is great to hear :-)
All in all a good day :-)
Full on 12k service and all fluids changes and changed all the fuels lines for me plus a few bushes and ball joi Ta
Still got the AFM / ecu issue who h I knew about so waiting on mark Adams for a test and fix price then I recon she will be minty minty
The guys at DG were very impressed with the car, especially the chassis which is great to hear :-)
All in all a good day :-)
gmw9666 said:
Have left Mark a message as if he can test / repair both items then bingo :-)
Well managed to chat to MA.........top chap.........so taken the AFM and ECU and will send to him for a testing to see what's whatThought I'd share my AFM stats just incase anyone cares lol (please note the measurements are taken with a tape measure so will not be 100%)
Never noticed the Plenum is stamped NCK with Internal Diameter (ID) of 72mm and Outside Diameter (OD) is 80mm
The inlet end of the AFM is ID of 66mm and OD of 69mm
The outlet end of the AFM is ID of 75mm and OD of 78mm
So the weird thing I noticed was the inlet and outlet are different sizes........and the inlet, it has a bloody great gap on the underside of the hose connector which sure would let un filtered air into the AFM???
Looks dodge so glad its being sorted once and for all :-)
pwd95 said:
Hi Glen, was away last week so just catching up. The AFM & ECU need to be 'together' so to speak in order to get the right fuelling so Mark Adams is deffo the right man to sort those for you. Good luck. 
yup, joined at the hip lolMark can event tweak the ECU to match the mods on 420 to maximize everything as well......could even make it adjustable.......top man and plenty of choices
Means I get to keep the injection OE spec which was my preference
Campbell said:
I should have read through this thread earlier as I have a tweeked Mark Adams ECU and flapper from my 420SEAC sitting on the shelf waiting for some one to make me an offer for it.
My 420 made 281bhp on the rollers at Shrewsbury Automotive with the owner Mike running the rollers and Mark tuning the flapper to the engine.
Great place and people and when you get your car back together you will need to get the car tuned on the RR.
Any one want to buy a tuned ecu and maching flapper
Cambelt
YHMMy 420 made 281bhp on the rollers at Shrewsbury Automotive with the owner Mike running the rollers and Mark tuning the flapper to the engine.
Great place and people and when you get your car back together you will need to get the car tuned on the RR.
Any one want to buy a tuned ecu and maching flapper
Cambelt
earlybay said:
Sounds like interesting stuff ... Im about to start delving into some ECU tweaking although I always understood it to be quite limited on the 4CU/Flapper...Id also like to stay with standard injection components rather than go complete Megasquirt, although that would be easier ...
Then you definitely need the services of Mark Adams......a legend with these 4CU's Gassing Station | Wedges | Top of Page | What's New | My Stuff