When a favour turns into a mistake! (2x dcnf issues)

L8AGN2

L8AGN2

Rolling rattlecan resto
I had my car in to a clients shop (they do fleet service and such) and had them set the timing and check the carbs for me. What a mistake that was. Timing seems fine but the carbs are just hosed now!

What i mean by that is it idles way to high, sputters and spits fuel back throught the air filter, idles way up if i come to a stop now (mine are mounted backwards remeber!) and also just cuts right out every so often (the car stalls , sits for 5 min and firs back up)

I never had these issues before and am VERY RELUCTANT to take it back to them ( i recall a post by Jimbro about headgaskets and the shop not knowing what they were doing). I have an appointment for friday at a local European shop(jag's, mg, triumphs, rollers, rovers all over the place!) to look at it but they may not be able to work on it that day.

Does anyone with dual dcnf's have a rough tuning setup (ya know , air 1.5 turns out etc etc)? Before anyone asks i do not have a sync tool and I know i need one , i just want this to be driveable for a few days till it goes to the shop to be done by an expert.

Any help here (in a step by step method) would be great.

I know there are other posts on dual setups but they don't really tell me what I need.

TIA
 
I don't think you'll be able to get this fixed...

....probably should just remove the twins and their intake and give them to me. I will trade you straight up for a single stock carb and intake. I will even cover the shipping. :dance:

Hopefully somebody here can give you a heads up. Do you think they were playing with the jets and screwed up their order?:shock:
 
Do you really want my ugly Sprint manifoldand old 308 carbs?

After all the time I spent polishing the runners and what not i would have to decline your generous offer! (so hard to type sarcasim!)

I figured while it was all messed up i would make the effort to flip the carbs 180 and see what happens. 2 hours in all seems to be well (only draw back thus far is i have no throttle stop as right now(i will remedy this in short order). Car fired right up (thank the powers that be!)

Off to get some threaded rod and see if i can sort the linkage. Wish me luck!
 
L8AGN2 said:
I had my car in to a clients shop (they do fleet service and such) and had them set the timing and check the carbs for me. What a mistake that was. Timing seems fine but the carbs are just hosed now!

What i mean by that is it idles way to high, sputters and spits fuel back throught the air filter, idles way up if i come to a stop now (mine are mounted backwards remeber!) and also just cuts right out every so often (the car stalls , sits for 5 min and firs back up)

I never had these issues before and am VERY RELUCTANT to take it back to them ( i recall a post by Jimbro about headgaskets and the shop not knowing what they were doing). I have an appointment for friday at a local European shop(jag's, mg, triumphs, rollers, rovers all over the place!) to look at it but they may not be able to work on it that day.

Does anyone with dual dcnf's have a rough tuning setup (ya know , air 1.5 turns out etc etc)? Before anyone asks i do not have a sync tool and I know i need one , i just want this to be driveable for a few days till it goes to the shop to be done by an expert.

Any help here (in a step by step method) would be great.

I know there are other posts on dual setups but they don't really tell me what I need.

TIA
Click to expand...

Get the old haynes manual for the 124 Coupe, it has one of the best step by step instructions for setting up dual carbs I have ever seen. Yes, it's for different carbs than yours, but it's all basically the same.
Then get a syncronizer tool, I don't think I paid very much for mine.
Get yourself a couple of simple carburetor rebuild kits with new base gaskets. When you pull the carbs to turn them around pull em all apart & clean them & set the float level before you try to set them all up.
It's simple.
Or, send me the car & I will set it up for you!
 
Too bad the Coho doesn't run * night!

I could catch a ferry but they don't run this time of night! Thanks for the offer though but I have it driveable again (mostly). I'll just have to wait till friday and see what they can do at the shop for me.

Gonna also have to get someone to weld my linkage a little better. It works but i have no way to adjust idle speed, which kinda defeats the whole purpose of this adventure. Wish my welding gear wasn't broken. Oh well , par for the course this week i guess.

Just need to make it to work in the morning without having to drive the Toyota or Pontiac (BCAA is great here if all goes wrong!)
 
Pat Braden's Weber book has a nice step-by-step setup for twins (not specifically DCNFs, but you will get the idea).

Make sure to get a good syncronizer, the cheap ones with the "floating bead" may not work well - if at all. The problem with these are that DCNFs usually have tall aux venturis that come up to the level of the airhorns. When you use the 'bead' type tool, you have to screw the adjuster down a long way to get a measurement and that can block the air going into the aux venturi - no fuel flow - .

It is possible to use the 'old school' method of using a hose and 'listen' to the hiss in the airhorn (I became quite good at this with my old Datsun Roadster). The trick to this is to use a small diamter hose (1/4" fuel works well) and hold the end of the hose 90deg to the airflow right at the top edge of the airhorn. Hold it in the same position and distance on all 4 throats and compare the loudness of the hissing..... DCNFs have air bleeds to adjust across a single carb, the inter-link is used between the 2. It takes a while to get it right, take your time....

Also, I have taken to adjusting the sync at an rpm higher that idle (say 2000rpm) so that I'm adjusting the flow of the carbs at a normal running opening - I don't care if it idles well as long as it RUNS well.
 
Paul... glad to hear ya got it running a bit better...

... Maybe its time ya consider maintaining your current philosophy...

"Why pay for someone else's mistakes when you can pay for your own?"

Especially if yur gonna continue to use duals... I've NEVER known a set of duals, tris or any other multiples that didn't need constant attention.

I recommend you follow Chris' advice... get it back to where it was before ya flip or modify anything else.

HTH...
 
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They are already flipped, but alas

I am at the mercy of international mail! My kits won't be here for another week or so. In the meantime i am going to have to fab up a new linkage. As for paying for someone else's mistakes, well i guess i shouldn't have expected much for free! If it wasn't a time issue (i had no where to get a sync tool at 8 pm here, i would be more than happy to do it myself.

After messing around last night for "a little while" i managed to get them back to where they were before all this, or close to atleast.

It will have to do till the kits get here!
 
... and might as well order a sync tool...

... since yur waiting.

Then ya won't be caught like this again!

You are indeed a patient man...
 
Its on order as should have been mentioned above!

Anyhow , broke down and went and bought an arc welder. Linkage is mostly good now (my welds are ugly but they will work)

Of note that may interest some people, as we know my carbs were mounted 180 to everyone else for some reason. I swapped them around and have noticed that my engine temp has dropped 3 ticks on the gauge. Doesn't make sense to me , but the gauge is pretty accurate (according to my point and shoot temp gauge)

Anyone wanna hazzard a guess as to why?
 
You might have changed the AFR, leaner runs hotter where as richer runs cooler. I do not know if its typically a noticeable difference, but that could explain it.
 
It just keeps getting better

So looks as though whatever was done at this shop they somehow managed to crack the manifold gasket (or more likely a strange coincedence). Arggh! Which would be why i was having such a hard time getting it to run as good as it should.

On a side note: They say bad things come in three's right? So the above mentioned counts as two , and the broken vbelt this morning i guess would be three. Good thing it broke infront of a Lordco store (karma or what!) 5 minutes and back up and running!
 
well its probablly running a tad cooler because the carb bowls are now more insulated than they were, at least from the exhaust manifold
 
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