Hi everybody, hope you can shed some light on this.
I have an Mk2 with 2.0 Pinto, FR32 cam, Ashley manifold and 32/36 DGAV.
I have been looking at Webcons Retrojekt, the one that bolts straight on 32/36 manifoil, and Microsquirt management for this.
Has anybody tried this, or have any info wether this is better than the 32/36? I like the idea of EFI because I feel that wathever I do with the carb I cant get it to run properly.
Thanks i advance.
what do you mean by you cant get it to run properly? if your issue is it doesnt idle very well, even injection may not totally cure it because the cam has a fair bit of lift on overlap which wants individual throttle plates ie twin dcoe or similar to idle well
Cold running is a pain, it hesitates and wants to die when I give it trottle. This is much better when warm, but I feel i don`t like sudden accelration even then.
The idle when warm is like it sucks false air, it Idles fine on 1000 rpm and suddenly drops and nearly dies. I have jetted it like Miniliteman adviced me some years ago, but can`t remember what jets i have in there since this is some years ago. I have written it down somwere though. It has an electric dizzy, 10 deg advance with vac off and blocked, and it does adjust when rewwed and it seems good. That is where I feel EFI has an advantage, you can set i up and it just works.
I should say I doesent have a lot of knowledge with EFI, but it seems more like a "fit and forget" than any carb.
Cold running is a pain, it hesitates and wants to die when I give it trottle. This is much better when warm, but I feel i don`t like sudden accelration even then.
The idle when warm is like it sucks false air, it Idles fine on 1000 rpm and suddenly drops and nearly dies. I have jetted it like Miniliteman adviced me some years ago, but can`t remember what jets i have in there since this is some years ago. I have written it down somwere though. It has an electric dizzy, 10 deg advance with vac off and blocked, and it does adjust when rewwed and it seems good. That is where I feel EFI has an advantage, you can set i up and it just works.
I should say I doesent have a lot of knowledge with EFI, but it seems more like a "fit and forget" than any carb.
If its not stock OEM - NOTHING is fit and forget and it most certainly doesn't 'just work'. With anything that can be tuned / adjusted the rule is - rubbish in / rubbish out, be it jetting / ignition timing or creating maps for EFI!
There is nothing “fit & forget“ about Microsquirt, it is an open source ECU and needs a competent tuner or a lot of knowledge to set up. You can use Autotune software that gets you somewhere near but will still need a dynotune.
As Graham said you have a camshaft/carb mismatch and that is probably the route of your problem, a simple set of bike carbs with a moan jet change to 1.5mm would work wonders
Thanks for all help guys. Bikecarbs has been in my mind too, but since it is a lefthand driver I have the tower for the brakeservo in the way, so then it is pedalbox and all that it needs and Mot does'nt really like that.
I stick with the 32/36 for now and see. Would been easy with the Retroject, tho.
Fit Piper 134 camshaft or any equivalent of the old Erson 134 profile (FR30 KENT). This cam is slightly faster as the cam you got right now but less valve lift at TDC (even less as standard). Will work perfect with 32/36.
Ok, decided to try to stick with the 32/36, can't let it win over me just yet. I know my cam probably is little too much for the carb, and it is practically unused, so will stick to thath. So if you can comment on what jets I have I would appreciate it.
Mains, 145/150
Airs, 170/170
F66 in both
Idles, 55/50
Forgot to say, the head is lightly ported.
Regards Mrmk2
Last edited by mrmk2; 23-06-2020 at 19:42.
My very old Weber tuning book shows basic from factory jetting which is different from what you have and assume because you followed jetting given to you from Miniliteman because you have the FR32 fitted.
Did it ever run properly? Or is this a new problem?
You want to keep the cam
You want to keep the carb
So your limited with what you can do apart from make sure the carb is not leaking air through the butterfly shafts or has another air leak.
Run engine spray WD40, carb/brake cleaner carefully around butterfly shafts, carb mating face to manifold, any vac pipes blocked or otherwise and manifold head face.
1 at a time for each area to see if revs rise.
Check your ignition timing at idle through to 3600.
I assume you have an adjustable vernier cam pully?
Do this and report back
Other things, manual or water choke?
Exploring the statement “lightly ported” it’s sounds like you have a non-injection head and standard valves so porting should be basically smoothing the inlet port short side turn.
With the carburetor setting of Miniliteman it should be running. It's probably still not 100% but it should drive. Otherwise you can try one step more rich in mains because over rich mixture will run (not ok for long time but it should run).
Idle can be bad because of valve lift at tdc but that's for later. If it does not run normal from let say 1500 - 2000 RPM up to .... you got an other problem and that's usual the case. But too often people start to blame the carburetor. That's also the reason why I don't sell rebuild or new carbs without a tune. You have no idea how many people do not even manage to get a fully tuned engine running in their car !!! already destroy the ignition or manipulate something they never thought it would harm.
Switching to fuel injection does not solve the problem, will make it only more confused.
i laughed at that, there used to be a old garage i used to visit, they had stacks of old carbs which they had changed because of problems, i used to buy them and fit them to engines where they worked perfectly without any repair!Originally Posted by onyd
Hahaha
If I get a phone call, they always need a carburetor or a new ignition. If I ask 2 more questions I already know it is none of them.
Few weeks ago, I had to start a fresh rebuild engine, dyno tested here in house and perfect running. It was erratic running in the car. The earth from the battery made a bad connection to the engine. Must say, difficult to find, I did saw an earth wire but you can't always see it is making real earth. You have to relay on the answer to you question, "did you cleaned the surface well before fitting the earth ? ". The answer is always "yes".
And you know they will be attacking that earthing point with a wire brush as soon as they've put the phone down!
Hahaha. No that's after 10 phone calls. I wish they would do it after the first one !!! hahaha
Thanks guys. Yes, I know it is easy to blame the fuelside, I will check everything and come back to you. I will most certanly learn somthing and it may help someone else along the way. Thats what it's all about, isn,t it.
Only way to learn, trial and error but never give up
You will indeed learn much as I am, there are very knowledgable people on this forum who give advice from experience willingly.
What ever you do please report back at every step, one of the most disappointing things is to have a thread die before a conclusion. When other search for information (as I have) and get to the end of the thread without an answer...
Totally agree, the knowledge on this forum is unbealiveble, and they probably has forgotten more than I ever will know.
I will come back with what I find.
does the accel pump, pump a jet of fuel in from the top when you operate the throttle ? look down carb with engine off and twist linkage sharply
Ok, got her out on the road today and here is what I found. Idles ok, but does not like it when I accelrate. It splutters an blow back in the carb. But I drowe her hot and started checking. Ignition was a little high so I adjusted it down to 13 deg whith vac off and blanked. It does not advance as much as I would like, about 30 degrees. Checked all sparkplugs, and found them to be white, too white for what I like. Nothing near the brownish I would like. BUT. On cylinder 2 it was all sooted so I expect it has'nt fired properly here. Could be nothing, because it has only been started and rolled out of the garage several times and not been driven warm for quite some time so if it starts to soot it will just be worse I expect. Back to the white sparkplugs, it seem lean but I think the jets certanly are big enough so I would expect them all to be black. I think I need to order a rebuildkit and some more jets. And check that dizzy. And checked for false air with brakecleaner and found nothing wrong.
Regards
did you check as i mentioned above ?
Hello Alladdin. Sorry, forgot to check that yesterday, so had a look now. And it does not squirt when quicly applying trottle. In none of the barrels. Maybe a split membrane?
Regards
possibly split or maybe blocked pump jet or its oneway valve is blocked, a 32/36 should ONLY squirt in the primary barrel
Some have a jet that squirts into both barrels.
yes ive seen that but they should not, all that happens is with light throttle use you build up a pool of fuel on top of the secondary butterfly where its not needed or wanted
Thank's guys. I will open it up and check. The gas these days is probably not so good for cars that is nestled un a garage for long periods either, so maybe it is clogged somwere. I will report back. I'm going to order some jets an rebuildkit from Burtons, I'm ordering some smaller and some bigger than what it got now. But can you say what sices up and down from the F66 thats worth having in spare?
Regards
No need to change the F66 emulsion tubes. You could buy some smaller and bigger main and idle jets.
But changing one size up on a main jet can be hard to notice.
If the membrane was split, fuel would run out of the carburetor, so that's not the problem. Something somewhere blocked or parts missing.
But to be honest, if you prepare the engine / carburetor for a run and it is not squirting fuel into the carburetor (acc. pump) I don't know why you even started the engine in the first place. It has to inject fuel or the engine will never run correct and it is one of those things you can check BEFORE you start the engine.
Please buy the most simple carburetor repair manual you can find and read it over and over. You are going to learn a lot. Of course, you must be willing to learn but I do believe you do. Much of the "black magic" of carburetors is so easy to understand with a few pictures and a clean explanation.
Here is what I found and done.
First I have the mecanical fuelpump so have to start it to fill the floatbowl.
As I wrote earlier it did not squirt from the accelrator "jets".
I took the top of the carb off an did'nt really find anything wrong, so i found some info on the acc- circuit om Webers site. The "banjo" that holds the acc nozzle is not only a banjo, it is a one way valve that prevents fuel to run back to the floatbowl, after the pump. Checked this and the ball inside was free and I could only blow trough it, not suck wich is good. In the bottom of the bowl there are 2 small holes on the side where the acc pump is. I took of the pump and would expect to see fuel, but it was dry. Checked the seetrough drawing at Weber an found another one way valve that you can't access unless drilling in the carb. I took my air gun and gently blew trough the holes in the floatchamber. But I really had to turn up pressure and then I heard a noticeable click and air came out of the hole inside the acc pump. Good. Mounted the pump an acc nozzle, because the one way valve in the banjo. You will not get fuel up without. Filled the bowl with cleaner, quicly applyed trottle and we have squirt! I found wery little info about this circuit, only funktion. I think this also has to do with tha anti stall aswell, because I checked that membrane aswell and found no fuel.
Checked floatheight an it was off, looks like it was adjusted as a brass one at 41 mm. Now it is at 35.
I wound the mixscrew all the way in and 2 rounds out, turned the idloscrew all the way out an in until contact with the link. Fired it up, would just barely idle. Turned idlescrew in 3/4 to 1 round, and mixturescrew in til it got rough agan. The mix is now 1,5 turns out. It idles fine and really picks up revs when hitting the trottle. But still not satysfied when driving. Much, much, much better but still hesitates a little when hitting trottle. Ignition is 13 deg vac off and plugged, gu15-18 when on.
And also, this carb squirt in both barrels, I aggree with Graham that light trottle would "owerflow" the secondary on light load but could be wrong.
So, any thougts on this is welcome.
Well the best thing you did today was reading info about the carburetor. Congratulations and I mean it. I do have a good feeling you now fully understand the whole acc. circuit and some others. This kind of people I want to talk to, that's not wasting expensive time.
People read hours and hours, evenings long trying to find the right info about there Megasquirt (and probably still got it wrong) but when it comes to carburetors, they read nothing at all, take the spanners, trow of the carburetor because "to complex in a modern world".
About the hesitate. First thing I notice, you vacuum is already pulling up the idle so what I already knew, the cam is not perfect for the engine, throttle plates are already too far open, so far vacuum hole is open. At the same time part of the progression holes already open and missing their function.
There are a few things that could be done here but most are one way so I suggest not to give it a try. First I would do is drive the car in second gear from as low as you can and increase the throttle very slow. Do the same for 3the and 4the gear. Not pulling the throttle fast but very slowly increasing. If all go well the jets are ok and all you probably need to do is fit a bigger acc. jet (or drill the jet). Or fit one that's blows only in the first step (at least only drill the frist step). If the test shows up hesitates (slowly pushing the throttle, not fast), try to increase the jets until it is driving correct. You should try idle jet also.
The acc. jet is only needed at quick acc. by pushing slowly it is not needed, not really working (or no influence) and this way you can check the jetting. This way you can tune the carb for 80% correct, even 100% if you are lucky. At least it should make the car run perfect (without fitting a laptop !!!)
Thank's Onyd, you are quite right, it is easy to bin the carb in favor to efi, but you are also right in the facination in having a problem an actually solve it too. I will stick to the carb and make the most of it.
I understand what you mean with easing revs up, when you mention it it was quite ok when doing this yesterday and I have thaugt exactly the same. This because now with the acc circuit ok it is as said much, much, much better but the "syndrom" reminds alot so if it was wery lean earlyer and nearly undriveable, it could be just a litte to lean now.
I would think the trottleplates would be less open now with alot less idlescrew. But I will order some jets, recheck ignition and try you're way of testing it.
Thank you again for all help!
Back again, and been playing around with the carb. I found that it did not respond on bigger acc jet, it did not cure the hesitation. So I started at the beginning and completely dismantled it, cleaned everything, jets and all fuelpassages and have now these jets:
Idle 55/50
Airs 170/170
Mains 170/165
Acc 55 singlesquirt
Aux 3,5/4,5
Drives really well, idles at 700 rpm with 1.5 turns on idlescreww, 2, 1/4 on mix screw. Ignition at 12 deg static and stays there with vac on. No smoke in the exhaus as I can see. But still hesitates on wot. But when cold or before hot it does'nt. So I think it gets too much air since it feels ok when chocke on. So mayby go down on airs? Any thoughts?
air you sure you dont have an air leak? the last thing you need to do is go down on the airs, they are already small in comparison to the mains. with mains that big you want at least 180/185 airs or it will be hideously rich at the top end, that wont cause your wot issue though.
have you checked the power valve is working? that opens to bypass the mains under WOT, if its not functioning you will need very large mains to make it run properly, heres a handy link which shows how to check it
https://www.classicfordmag.co.uk/wp-...structions.pdf
I have sprayed start gas on all hose connections, intake manifold and the carb itself and it is ok. Checked membrane in dissy, ok. When giving it wot I feel it will rev for a small second, then it starts to judder and hesitate. So I think this is the acc squirting and when it has done that it hesitates. Also little pussled by that it runs ok with chocke engaged. Thats why I thaught less air in the emulsion could help. Checked the power valve like in your link and it works.
Thank you for answering.
Last edited by mrmk2; 20-09-2020 at 08:44.
If the main jets really are 170/165 then change them to the 145/150 mentioned earlier.
Just tried these jets, Miniliteman, and it is much better but still not good. Drives soo sweet on cruising and normal trafgicaccelration but not on wot. But when between cold and normal temp it works fine.... It has the water connected to the manifold so that heats up like it should. It has no airfilter on now just to save time when working on it.
Some carbs don't like operating without filters / airboxes due to disturbed airflow? Try with the filter, it may be that simple?
When working correct between cold and almost normal temp it sounds like it is still somewhere too rich. Is it automatic choke? choke is fully open at this moment or still working for a small amount?
If choke is not longer working, cruising is correct, I should try a smaller acc. jet. Maybe it's over fueling at acc.
What kind of ignition are you running? Nothing getting hot? What plugs are fitted?
It is an autochoke, water. Works fine, that is not the problem. Plugs are brand new NGK from Burton, ngkap6fs on their website. Electronic dizzy, Ford. Not an aftermarket one. Coil is newish, some years old but very little runningtime. It is now running a 55 accjet, I can try a 50 and see.
Thanks Onyd.
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