DRLA 45 backfiring out of carb and exhaust (SOLVED)

[evanfrucht]

[67rustavenger]

Evan, when you say you pulled the jet stack. Did you mean the idle jet stack?
I get that this stack removal helped the engine idle better. So no need to rehash that.

If it was just the idle jet stack. Have you tried swapping the stack from #2 to #1 to see if this cleans up the idle issue?

another question. Have you completed the cam/lifter break in? It's generally recommended to get this step complete no matter how shitty the engine is running. Then get after the tune.

I'm gonna stuff my 2180 in my car this weekend, I imagine that come Monday/Tuesday, I'll be as soar as all hell!
_________________
I have learned over the years.
Cheap parts are gonna disappoint you.
Buy Once, Cry Once!

There's never enough time to do it right the first time. But there's always enough time to do it thrice.
GFY's Xevin and VW_Jimbo!

[evanfrucht]

[evanfrucht]

I found out I'm pretty close to Mcdragracer actually so I'm going to drive over there later today and hand them off to him. I would like to know for sure the carb is bad or find whatever is wrong before I buy a replacement.
_________________
1967 Bug ( the daily rod )
1964 Fury Wagon ( the pavement shredder )

[txoval]

You can’t go wrong with mcdragracer

You open the dictionary to Good Customer Service and Open Communication and his picture shows up.

[evanfrucht]

[67rustavenger]

[txoval]

Not many others will text you at each step including the weekends.

[Chickensoup]

[VW_Jimbo]

[Chickensoup]

[74 Thing]

Rick does good work so hopefully he finds the problem. A second set of eyes is sometimes a good thing.

I am pretty sure it is not an ignition problem since you swaped carbs side to side but what kind of distributor clamp are you using. The aluminum colored aftermarket ones can sometimes create a grounding issue.

In the future do not use 150 psi or air to blow threw the carb. That can create issues with all of the lead plugs. As you know the idle jet circuit is pretty simple in those carbs. From the top there are fixed idle air inlets (are they all the same and is the hole clear from the top into the idle jet holder thread area). Then there are the idle jets and holders (are the jets the same as well as the holders (check the holes) and the rubber o-rings). From the top view down it goes into the bowl but towards the top near the threaded area there is a hole where the gas goes down to the progression ports to the mixture screws. You can put a car cleaner tube in there and spray some fluid down there. You can remove the progression port plug (big phillips screw head on the side of the carb above the mixture screw) and see if the carb cleaner comes through. Then there is the mixture screws (check the o rings on these and the seating area. Finally there is the air bypass (how are the o rings on these and is it not leaking air.

When I clean a Dellorto carb idle jet circuit I will remove the jet from the holder and use carb cleaner and air to blow it out. I will also remove the progression port plug and put the carb cleaner straw in the downward port and spray and make sure carb cleaner is going through that. Then I will replace the progression port plug and remove the mixture screw and again spray carb cleaner down the circuit passage and make sure it flows down. I will also spray through the mixture screw passage into the carb barrel. Finally I will spray air upwards from the mixture screw through the open idle jet holder area. Then replace the mixture screw and idle jet holder.

Again, I am sure Rick will hook you up.

[67rustavenger]

This thread is becoming a how to diagnose Dell issues thread.
And it has some great content.

After reading the last two pages. I feel like I have a better understanding of the inner workings of Dell DRLA carbs. I've had mine for 3-4 years.

Thanks to Modok and Evan. Props to Ohio Tom and 74 thing too.
_________________
I have learned over the years.
Cheap parts are gonna disappoint you.
Buy Once, Cry Once!

There's never enough time to do it right the first time. But there's always enough time to do it thrice.
GFY's Xevin and VW_Jimbo!

[evanfrucht]

Well, Rick has my carbs now. He couldn't find anything on the bench majorly wrong with them and is going to test run them on an engine he has by mid next week.

So I guess we will see what's up

He was able to tell me I've been setting my float level like a dipshit
And he found one idle fuel delivery hole to be a hair smaller or with a tiny burr or something but it was insignificant enough neither of us are convinced that was the issue
_________________
1967 Bug ( the daily rod )
1964 Fury Wagon ( the pavement shredder )

[Chickensoup]

well until you get your carbs back just slap a stock intake and carb on there. maybe it will make you appreciate the power increase once you install the dells afterwards
_________________
-'85 c10 5.3 LS, 222 cam, long tubes, x pipe, 3 inch spin tech's
-'05 B5.5 TDI Wagon 17in sport rims ;EGR + BSM + ASV Delete, Stage-2 Tune, straight pipe
'65 Tourist Delivery Build
'66 RIP
'69 RIP
Hosea 4:6 "My people are destroyed for lack of knowledge"

[74 Thing]

Here are the guys at Blackline (formerly Art Thraen's shop) showing how to set floats on IDF's-the process is similar to Dells.
https://www.youtube.com/watch?v=54uPwTZ3DJw

Also since your carbs and manifolds are off look down the ports to see if your valve guides have walked any. Brian E suggested earlier to pay attention to the seats as well so may as well check the intake guides visually for movement and a possible intake leak.

[evanfrucht]

[evanfrucht]

I talked to Rick today. He fixed my float height and reamed/cleaned up/evened out in size the idle circuit fuel delivery holes (the ones that the mixture screw go into) on one carb so far. He then ran them on his test engine. He said he immediately new it sounded lean and was popping like I said and that it was the worst on number one. He said it sounded like it wanted bigger idle jets. Like way bigger! I had 63's in their which he sold and initally recomended to me but after running it on his test engine he said it sounds good with three 76 idles and one sized 80 in the cylinder number one.

He also said that it seems like the throttle bearing on the #1 cylinder seems to be acting like it has a slight vaccum leak even tho that is apparently very rare. But he also said that he wouldn't worry about. It still kinda bugs me tho...

He sent me a video and they sound good on his test engine. I'm still kinda frustrated with this particular set of carbs tho. Why do they want huge idle jets? Won't my gas mileage be shit?

Anyway, in the mext couple days he is going to check the idle fuel delivery hole size on the other carb and try a few other things and fine adjustments so we will see how it goes.
_________________
1967 Bug ( the daily rod )
1964 Fury Wagon ( the pavement shredder )

[modok]

Your killing me with all the suspense.
There must be a reason

[evanfrucht]