32/36 DFEV setup on 1592 with single plane

[Amendonsa]

Happy Sunday all.

I am finally getting around to installing an EMPI DFEV that I got from Csaba last year. It was appropriately jetted for the engine and intake. It is now mated to a single plane intake, with all ports blocked.

I am carb illiterate and will do my best to explain my issue before I tow the car to a shop. Hopefully it is something simple that I have overlooked.

Background:
Car is a 1973 Spider, 1592 engine. With the original carb and intake it ran fine, but slow. Decided to upgrade.
Prior to my ownership, the car sat for an extended period of time, so the gas tank is suspect. But, seemed to run fine on the old carb.

Issue:
Car will start and idle fine. However, as soon as any gas is given, it will stumble and backfire. Other research says this means lean??

If I very slowly press the gas, I can get it as high as 3500rpms before it will start backfiring. Under quick throttle, backfire is immediate. Cannot be driven as any distance as any amount of load causes backfire and no power.

Done so far:
The fuel pressure seems ok for a mechanical pump, measured 4-5psi at the carb. New lines and fuel filter.

I set the carb initially per instructions (I think). But I found no amount of moving what I believe to be the mixture screw in or out had any effect. I believe what I was adjusting was the proper screw, the one with the spring on it.

I am attaching some photos in the hopes that someone has an idea of where to go next, or sees something obviously installed incorrectly or not addressed. There are a few ports in the carb which are currently not connected to anything, but I believe I read elsewhere that they were unnecessary. The vacuum line from the manifold to the brake booster is installed.

Thank you in advance for any advice and help!

[azruss]

sounds like you are getting too much air with the throttle. Don't know carbs good enough to tell you where those 2 ports go. My guess is they shouldn't be going to open air.

[70spider]

I noticed your fuel filter does not have a return line. When I switched to the 32/36 DFEV it does not have a provision for the return fuel line. I got a fuel filter that solved this: http://www.amazon.com/FRAM-G3583DP-In-L ... B000C2ZJRU. Also on the vacuum ports I capped them off. I also changed the jetting on the carb, my post on jetting may help you http://www.fiatspider.com/f15/viewtopic.php?f=5&t=32533

[So Cal Mark]

you can't leave vacuum ports open, they have to be connected or capped. If you're using old fuel it needs to be drained and fresh fuel added. To determine if it's too lean, hold the choke partially closed and see if that affects how it runs
Is the ignition timing correct?

[Amendonsa]

Thank you all for the replies.

I will try capping the lines and see if it helps.

The fuel was fresh last summer, but I do not know how long fuel typically stays good. Im guessing in California it may be a bit off.

I tried blocking the choke open to set the carb, I did not experiment much with it closed. Although, if I recall, the car seemed to run a little better as it warmed up and the choke opened.

I assume (I know) that the ignition timing is correct, as I did not change anything since it last ran. But it probably wouldn't hurt to confirm that.

Thank you all. I now have a few directions to start heading. As always, I appreciate all the help from the board.

Andrew

[Amendonsa]

Mark-

Can I assume that the two ports directly above the adjustment screw are vacuum ports? I should be able to just get some little vacuum caps to seal them, right?

[So Cal Mark]

they are vacuum ports, cap them if you don't connect them. Fuel doesn't last long since it's now laced with ethanol. If the fuel is 9 months old it's not very volatile. I'll assume you still have points, set them correctly then check the timing. Make sure the advance works when you rev the engine

[rjbaum12]

I have the same issue with the stalling/backfiring when cold as you describe. I was thinking it's a choke issue as once I let it just sit and idle until warmed up it runs fine. Have you sorted this out?

[So Cal Mark]

is your choke closing when cold?

[Amendonsa]

I can add that the problem was identified and Mark hit the nail on the head. The distributor advance was seized, which must have happened while sitting. So timing was indeed the issue. Runs like a champ now. Hope that helps.

[rjbaum12]

Thanks guys. I'll check the distributor advance though I think that's ok. I'll have to look at the choke - I've been trying to adjust it but it looks to me like the linkage was taken apart at some point and isn't put together properly. I've been able to drive it just fine as is by just letting it warm up so it hasn't been a real concern - I'd just like to get it sorted at some point. As is it performed quite well on a recent lap around the Circuit of the Americas track.

[So Cal Mark]

check to see if the choke closes completely when cold. We've seen a few of the choke pull off rods that rotated in the housing and prevents the choke from moving freely