I'm not 100% sure of anything at this point
I'll give it a try. What does the water do?

Change the idle speed as water gets sucked into the vacume leak and momentarily stops the leak.

Long shot here. Looking at an illustration in tomlinson's del manual. Is there any chance you overlooked the port below the throttle plate that the idle air mixture screw controls for flow at idle? If you have the book it's on p.50. The hole/port would be below the throttle plate when closed.

If you mean the hole below the throttle plate that the idle screw points into, yeah I have. I've blasted out every port, hole, and pathway on the carb. Even the ones not related to the idle circuit. But yeah, with the idle screw removed, I can see straight through into the inner bore of the carb. It's clean.

Like said, long shot. There's only so many places the fuel can escape once it's beyond the float valve. Perplexed. I surrender.

I'm in the same boat, man!

good tip ,used WD 40 lots in the past ,water is less suitable,type 4 heads do pull intake studs,most people overtighten them,wondering cause the OP has little adjustment on the air bleeds = air leak.
Are there equal reading when you check the vacuum @ the throats.
Dells are great carbs don't give up,you will get there,OMG you deserve to.

I have used spray carb cleaner in the past but didn't want to take the powder coat off the tin with it. WD-40 would work. All you are trying to do is see if you can detect a change which would mean that you have a vacume leak.

You said the head to manifold plastic isolators you used didn't have gaskets on them. What did you use for gaskets?

You could swith carbs from side to side to see if the same cylinder is affected but that seems like a lot of work.

I tried spraying water all around both ends of the manifold but didn't notice any change in rpm. My wd40 is just about empty and not enough was coming out to use. One thing I have noticed is that if I smother the input to #3, the AFR goes perfectly back to the 12's. But the idle speed doesn't increase when I do this, which is what I thought is supposed to happen with a vac leak.

I thought the plastic spacers were the gaskets. You're saying that there needs to be a gasket in addition to the spacers?

Yeah I don't know how I'd get the linkage to work if I swapped the carbs. I suppose I could just crank up the idle screws until it warms up.

The plastic spacers I used have thin gasket material attached to both sides. Seems like it would be an easy place for a leak.

You could switch the carbs and not hook up the linkage just to see if the same cylinder is not responding to the idle screw. That way you would no if it's the carb or a possible vacume leak.

I vaguely remember that the gasket at the base of the carb that came with the Dellorto rebuild kit was not as good as the big thick gasket that I was running before I rebuilt the carbs. I installed the Dellorto gaskets but then ended up replacing them with the originals.

If this was my car, I would yank the carbs and install a Ljet FI system. Be that as it may, I do like the idea that was already tossed around with swapping the carbs with the other bank. Its a fairly quick way to isolate if you have a problem related to the carb.

Ljet will work on a 2270???? Tell me more of this amazingness of which you speak!
Seriously though, really? I would loooooove to get rid of these carbs. I've been considering the idea of selling this car for the last six months or so, just because I'm freaking tired of waiting for carbs to warm up anytime I want to go somewhere, and $3K+ for the Dubshop's ITB setup is not in the budget right now.

Yeah the last time I bought the spacers they had the thin paper on them, but this time not. I wasn't sure what was up with that. It seems to be holding strong on the 1/2 side though. Maybe I'll order another set and see what happens.

I'm actually running the thicker gaskets from CB between the carb and manifold. Those wafer thin little things that came with the rebuild kit didn't seem like they'd hold up.

I'll try swapping carbs and see what happens.

If the plastic spacers are just plastic with no paper gasket that could be the source for a vacuum leak. Both surfaces would have to be perfect not to leak unless you used some kind of sealer. The ones I used looked like this:

Click to view attachment

... you definitely need more than just the plastic. Did not know that this was the situation till you said that Dustin.

In the meantime, you can try these Dustin...

http://www.cbperformance.com/SearchResults.asp?Cat=270

These are paper gaskets which can be used totally in place of the phenolic spacer. Or, you may to chose to order 4 of them, and put one on both sides of the the spacer, then bolt the manifold to the head.

Use the 2725 gasket if you have 2.0 heads, or the 2724 if you have the 1.7/1.8 heads. Maybe even order a few extras since they're so cheap. I personally like to use a little RTV to glue these paper gaskets to the phenolic spacer, one on each side, making a total of 4. Then I use a little grease on the paper side and bolt the manifolds on. Not had a leak since.

You may ALSO take the opportunity to order new "2700" base gaskets (on the next page) since you have removed and installed the carbs so many times now.

Let's start there. I know you have to wait, but it's a lot cheaper than sending the carbs off at this point and we can further troubleshoot the situation.

Well damn, I can't believe it might something that simple! I thought it was odd they didn't have the paper. I ordered the VR ones from Pelican that I always get. I wonder what happened that they didn't have the paper. I thought maybe it was non-essential. Lesson learned!
I'll go ahead and order those gaskets from CB. It usually only takes me a couple days to get stuff from them.
I HOPE this fixes the problem!!!!!!

Hope so too. Not getting my hopes up, but it's the next most logical and cheap step. Generally that guides my workflow. When I've exhausted traditional troubleshooting techniques, I start with the free stuff, then the cheap stuff and work my way up to swapping out parts as a last resort.

Ljet should work fairly well with your size engine. Some tinkering will be needed with the air flow meter but very doable. You would need to make sure your current cam is compatible for FI

Hang in there Era. There's no doubt there is a simple solution to this, because your setup is proven to work. I hope you find it soon and then all this will be worth it, and a ton of people will learn from it.

No doubt FI will be a nice upgrade at some point. But when that time comes, a more modern solution (Megasquirt or whatever is the best value at the time) will make way more sense on a 2270+ than the OG stuff.

If you have some 3M spray glue or some of that Permatex copper spray gasket compound you could make your own using a thick paper. Like maybe manila folder paper. Glue the paper to the phenolic spacers and use some grease between the paper and the head and manifolds. You could order the CB gaskets but I the 2 gaskets plus the phenolic spacer would end up being too thick.

Ed, you're saying the spacers are just plain material with no facing on both sides of the part? I had never noticed the price dif on the offerings at pelican. VR @$8.25 vs $19.50 for the "OEM". Pictured parts appear to have printed surfaces on both items. You would think if the ones you are using fail to seal on one cyl they could fail on the other 3. A hassle but try lifting the carbs off as they sit and switching them around. Due to the dual fitting on one carb you might need to get a longer section of hose. Did you do the flow measurement on each of the 4 throats?

Yeah its just plastic with none of the paper material on either side. It's weird because I've bought those same cheaper VR ones before, once for my old FI car and then once for this car shortly after I bought it because the PO only had paper gaskets on there. Both times the VR gaskets had the paper facing. This 3rd time they didnt. Maybe a manufacturing error?
Flow test...you mean with a unisyn? I can get them to match but I have to crank up the idle screw alot more on the 3/4 side. And it doesn't seem to be stable. Sometimes it's higher sometimes lower without me changing anything. Could be due to a vac leak letting more air in somewhere else I guess?

I'm going to try George's idea of the CB gasket on both sides of the phenolic. My intake studs look like they have enough length for it to fit. If it doesn't fit i'll try Mark's suggestion of cutting my own.

Maybe an issue with the intake to carb base junction? If you use the one idle speed screw method to increase the rpm (1700 rpm or so) and then use the Unisyn you're eliminating what might be a false balance with the idle speed screws. Off stop the linkage is in a more natural position. Even a little linkage play can really wreck havoc. The most pressing issue is if the cyl is dead thru out the rpm range.

if the phenolic spacers have no gaskets, then they are just that. Spacers. To isolate the head heat from the carb. Helps to keep the fuel cooler. Order 4 gaskets, or use gascacinch.

Gotta be it. Everything so far has pointed to a vac leak. I'm going to miss this thread once the issue is solved.

Cheers to that
I think this is my longest thread I've ever had. They normally barely make it to two pages
I gotta say this forum and the folks on it kick ass! I so much appreciate all the help and insight.
Now it's just a waiting game until those new gaskets arrive.

Did you get it to work?

I have always used the phenolic spacers and RTV Blue silicone on both sides.

Still waiting for the gaskets to show up. Original delivery date was friday, but they never showed up. Then for some reason they went to Washington DC over the weekend, then to Maryland. They're in Raleigh today finally. We'll see if I get them today or tomorrow.
Of all the shipments to be bizarrely rerouted and delayed, this wasn't the one I needed it to happen on!

I fell off this one.....recovering on stupid pills....made me (believe it or not) even more stupid.

So, let me know if you still need them, I can get out again so I will ship them if required.

Rich

No worries, Rich! I'll see if these new gaskets cure the problem. If they don't, then I'll take you up on that offer

YYYYYYYEEEEEEEEEEEEEEEESSSSSSSSSSSSSSSSSSS!!!!!!!!!!!!!!!!!!

The new gaskets did the trick! Just came back from a test drive after tuning and timing. All's good. Head temps are running a little hotter than before about 7-8 degrees on the 3/4 side, I probably need to tweak the linkage just a hair on that side. Those arms are so sensitive to the slightest adjustment.

But it's running great, AFR is great, and the idle is stronger than it's ever been.

Thanks so much guys! All of you are awesome for walking me through this and all the help and advice.

Lesson learned about those phenolic spacers from PP. Just because the pic has the paper gasket, doesn't mean they come with one...and they are needed!

Damn! That's what I was going to suggest near the very beginning of this thread. But I didn't, so I lost my chance to look smart. Isn't that some law or something, think of all the possibilities and then choose the simplest, because that's probably the right one? I think it is.

No paper gaskets required. One of the few places on these engines that sillycone cannot cause harm.

Ha! It's like when you think of that witty comment about 10 seconds too late after the subject has changed in a conversation, and no one will ever know that funny thing you thought to say. Oh well. All's well that ends well.



I'll rephrase, the phenolic spacers can't be used as a gasket on their own.
It's weird though that in the past they've come with the paper gaskets attached to them, and this time they didn't.

Spacers were never intended to be gaskets. It's up to us to make sure things are sealed properly.

Thanks so much for sharing the results. Some threads die with no answer. So great to hear a win!!

Tell that to Pelican
Their site is why I thought it was a gasket. Learned something!

Happy motorvating.

Oof, yeah. And it's not always so simple because some surfaces need an extra sealant and some shouldn't have one. Thanks for sharing everything on this thread. It helps all of us learn.

A *thin* layer of the right goop on intake related connections has never scared me. It's simply about air-tight. The wrong kind of goop (or the wrong amount of it) connected to engine internals or high-heat applications is another matter.

Well after all the headscratching I caused you guys, I felt it only right to post the results! And yeah, I hate it too when you're trying to find info on an issue you're having, you come across a thread that's exactly what you're looking for, and then there's no answer ever posted.

Great news. I was hoping this is would have a good ending. Especially after that one member you so badly on that rust bucket that he sold you. What was his name again?

Scotty Boy
#neverforget
As long as he continues to post on this forum, I will never let that asshat forget what he did.

But ANYWAY....
All's good, just in time for some good driving weather!

Glad we were able to get it figured out Dustin. Sometimes it's the simple things. The hard part about diagnosing stuff over a forum is getting all of the little bits of information that would be more obvious in person. You deserve a good drive after that one though.

Haha, yeah I bet you would've known from the get go in person. But at least I got to learn a lot about my car in the process.