EA81 Hit carb issue

[MaddCelt]

In previous posts I asked what could be causing hesitation and idling issues. I looked into all the usual culprits as instructed on here with no success.

 

I finally got a chance to look into the primary barrel and found the problem. The copper tube that the fuel is sprayed out of is somehow extended into the inner tubes wall and bent to some degree.

 

Has anyone ran into this issue and aside from pulling the top of the carb off, is there a way to move the tube back, even a small amount so fuel gets into the carb better till I can get the needed parts? Also, what would have cause that to happen?

[Loyale 2.7 Turbo]

Usually those fine tubes got a small bent in Old Clean Jobs and they Continue Working like That without Notice Untill they got Clogged...

You can Disassemble the Carb and Try to Straighten it a Li'l Bit with a Very fine Steel Needle, but be Careful 'cos the bent tube can Break.

Maybe you can Replace it... or even Better: Swap a Weber Carb There!

 

Good Luck!

Kind Regards.

[GeneralDisorder]

I don't think you are seeing what you think you are seeing. The only copper tube in the primary of the Hitachi's (I just looked) is the accelerator pump nozzle and that is cut at a steep angle so it should still not be blocked. And in any case that would only result in a flat spot under rapid throttle opening - which could be described as a hessitation. But it would do nothing to the idle and if you open the throttle slowely it would not produce a hessitation.

 

Can you get a video of what you are seeing? Or at least pics? It's hard to do this from a keyboard.

 

The Hitachi carbs are notoriously hard for people to rebuild correctly the first time around. It took me half a dozen tries before I got to where I could rebuild one and make it run in an acceptable (to my standards) way. I can rebuild your's for a reasonable fee but it's usually more cost-effective to just upgrade them to a Weber. That's what I reccomend.

 

GD

[MaddCelt]

GD

 

At first I was going to say "I know what I saw!" but I did a search online for what I saw and realized you are correct. I don't have a pic of my carb but here is what I found online and I see what you were refering to.

 

 

On the left is the tube I was refering to and seeing here it is what I was seeing yesterday. When running, how should the fuel be spraying out and from where on the tube?

[GeneralDisorder]

There are different types of nozzles based on that picture and what I saw in the one I looked at ('84 model). Some have two that are like the secondary in that pic (cast nozzle - that's how the '84 is), and some are a brass tube that's inserted into the venturi and has a slot cut into the bottom of it.

 

So what are you seeing in yours that's troubling to you?

 

The fuel should be a spray like from an aerated faucet. Should be nice and even.

 

GD

[MaddCelt]

That is how mine is set up, the full length jet in the primary and the short one in the secodary. Having no clear reference in my books I thought it forced over. The spray from it was poor and only from one side, reenforcing my thought that it wasn't right.

 

The spraying isn't solid from what I saw and you can hear the spray sputtering instead of a solid spraying sound. Likely it's a slit in the bottom like you mentioned and it's plugged. That would also explain why it would run better when I closed the choke manually, less air, more fuel ratio?

 

There are different types of nozzles based on that picture and what I saw in the one I looked at ('84 model). Some have two that are like the secondary in that pic (cast nozzle - that's how the '84 is), and some are a brass tube that's inserted into the venturi and has a slot cut into the bottom of it.

 

So what are you seeing in yours that's troubling to you?

 

The fuel should be a spray like from an aerated faucet. Should be nice and even.

[GeneralDisorder]

I doubt very much you will find any sort of clog in the nozzle. Correct terminology is key when we talk about this - that's a nozzle not a jet. Not trying to be an rump roast but we *have* to agree on the terms being used or there really is no communication with something this detailed and complex.

 

Much more likely there is a problem with the carb top gasket partially blocking a passage, or some gunk in one of the air bleeds or main jet (bottom of the float bowl).

 

It does sound like there's a clog somewhere or you have a vacuum leak or something. Remember that carbs are operated by pressure differential created by the airflow into the engine - thus a problem with that airflow will affect how the fuel and air flow through the carb and can show up as poor spray patterns, etc - due not to the carb itself but to some other problem with the intake tract.

 

GD

[spazomatic]

often times emissions doo-dads can give ya grief too, and act just like a carb problem. I kinda like the hitachi, but all the stuff plugged into it pisses me off! good luck resolving it!

[MaddCelt]

I finally found the culprit.

 

Turned out to be the intake manifold gasket. You can't hear it but if you hit it with carb cleaner you notice it.

[NV Zeno]

Intake gasket, huh? Haven't heard about that being a culprit with these Subies, but it was definitely something that happened more often with our muscle-cars during our high school days (about 10,000 years ago... ).

 

Glad you found it..I'll have to double check mine.

[MaddCelt]

I didn't have the problem when I drove 12 miles to work on country roads but I got out on the hiway with the new job, 65/70 mph for 45 mins looks like it took it's toll.