• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

76 with fuel problems

Share this page

jcatnite

jcatnite

Jedi Knight
Offline
Greetings everyone. Pretty new to the forum but thought I would start by saying it seems as though there is some really good info bouncing around here. I recently purchased a 76 Midget that has been treated pretty badly for a long time. The only thing that keeps it from being a basket case is the fact that the actual body isn't rusted out yet. The most immediate concern I have is the fuel tank. The guy I bought it from told me that it was rusty but "he had it repaired"...lol. I would like to put a new tank on it but am concerned over the vented non vented issue. I would like to get rid of the vapor canister all together if possible. Does anyone have any experience with this? The car is running so rich right at idle that I'm pretty sure it will foul the plugs every 50 miles or so...lol Thanks in advance,
JC
 
OK new twist. The PO tells me that he had the fuel tank serviced professionally and that it shouldn't have anymore rust in it. I'm going to work off that assumption until I can siphon some out through a rag to see what it looks like for myself. But, I was messing with the carb trying to lean it out when I decided to pull the hose from the evap canister off to see what it does. What a difference. This little homemade vacuum leak made it run so much better? I pulled the hose that "T"s between the valve cover and the none throttle cable side of the carb. There is a little blowby coming from the valve cover but not really that much. It's pretty neutral till you tach the engine up pretty good. Anyway, any ideas on why pulling this line from the canister would make it run better? It not only jumps the idle up about 200rpm but it smooths it out so much. At this point I'm pretty much fishing for ideas.
JC
 
Hello Jc, and welcome to the forum!

checking the fuel tank is no big deal if you open the trunk and pull the fuel filler hose off and take a peak inside you can get a pretty good idea of what it is like inside of there. Please dont use a lighter to peer down inside of there. as far as it running better perhaps you have a plugged canister or a pinched line somewhere? also ther should be a second canister up inside the right hand side of the rear fender (near the fuel filler hose) check here for any obvious problems

mark
 
LOL...I'm resist the desire to stick a lighter in the tank... I'm not that frustrated with it yet. As far as the canisters, I didn't know about the second one in the rear fender. I will check into that. Is there any way to tell if the canisters are bad or is it just a part swapping deal?
Thanks again,
JC
 
Hi there, and welcome to the forum. The "canister" in the rear fender is a separator to keep liquid gas from going up through the vent lines to the vapor canister under the hood. My car had an unpleasant experience when the old rubber line split off that separator and started siphoning fuel into the trunk! /ubbthreads/images/graemlins/shocked.gif I would have to agree it sounds like maybe you've got a blocked vent somewhere. Mine was running pretty rich too until I rebuilt the carb and got it adjusted.

-Dave
 
Thanks Dave,
Looks like I'll have my head stuck in the other end of the car tonight. That will be a nice change since I've spent so much time with it stuck in the engine compartment lately...
JC
 
Looking for the vapor canister. Can't find it yet. But did notice a drop of fuel hanging to the bottom of the tank...whimper... So now I know why the garage smells like a refinery today. Looks like the tank is coming off...
JC
 
Hi again JC, the vapor canister should be near the firewall on the right side of the car, sitting on the inner fender. Look for the big round thing with a few hoses coming out of it /ubbthreads/images/graemlins/wink.gif. Hope that helps!

-Dave
 
Thanks Dave,
I found that one. It actually wasn't stopped up as even though I thought it was. The one that is supposed to be in the trunk has been removed and the hoses are spliced together. I've been all over the engine and just can't seem to get it to idle smoothly. Did a compression check and got 145, 160, 135, and 125. 3 and 4 don't hold pressure very well. Suspecting that the valves are getting close to needing a head job. Between the valves and the Zenith that won't lean out I'm about to get decide to just through a bunch of money at it and start from ground zero...lol
JC
 
My 76 did not have that second canister in the trunk. All it had was the cansiter up front on the fenderwell. The charcoal there did plug up though.
 
I'm assuming it is ok. I can blow through it with little to no resistance what so ever. I think it is ok?
JC
 
Sounds like maybe your charcoal canister is okay then. As for the running rich, there's a variety of reasons the Zenith can do that. There was a very good article by John Twist of University Motors about the Z-S, but I haven't been able to find it. The title was something to the effect of "Those Darned Zenith Strombergs", but "Darned" was something else ;-) (sounds like "bammed"). The choke assembly may be loose, the choke needle valve may not be sealing, the auto choke may be out of ajustment, or the vacuum kick piston (which closes off the choke a little when the engine starts) may be stuck, the diaphragm may be leaking... Lots of reasons. Mine actually had a clogged heater return line, so there was no coolant flowing through the auto choke. I'm assuming you have the adjusting tool for the Zenith needle? You can get more adjustment out of that than out of the idle air screw on the side.

Here's a link to a site that had some good info about the Zenith, which I also found helpful. If I can find a link to the article I mentioned, I'll send that along. Good luck!
https://www.chicagolandmgclub.com/techtips/general/generaltips.html
-Dave
 
Thanks Dave,
The carb actually has a manual choke on it. I haven't taken the carb apart to see if there is anything stuck in the choke yet. I have been playing with the needle quite a bit. I'm thinking that I may have ignition problems that are causing me to suspect the Zenith. You can get to Dr. Twist's article at https://www.sterlingbritishmotoringsociety.org/files/zenith%20stromberg%20tech%20tips.pdf. I found the article to be very enlightening. Thanks again for the help.
JC
 
Back
Top