Tri-z fuel problem

[King Trikester]

I believe I'm not getting enough fuel, can someone please explain how the fuel pump works in an 86 Tri-z?

I took my Z out for the first ride today after a fesh rebuild, the carb and the fuel pump were taken apart and cleaned. It ran really great all day and at the end of the day it started bogging and dying out. It's intermittent it will run great and it seems like when it really makes power or is using lots of fuel it bogs out, like it starving for fuel, if I let off the throttle it seems to come around for a while.

I'm guessing I need to clean out the fuel system again and install an inline filter, but I would like a better understanding of how the fuel gets from the tank to the carb

[muthey]

I have no experience with a 86 tri-z but per the parts fiche it says the fuel pump is the same between the 85 and 86 , your fuel pump is driven by a vacuum hose on the bottom of the cylinder. if the diaphragm is wore out or develops a hole you will lose fuel flow. also if the vacuum line cracks it will not pump enough fuel. I would look into the fuel pump and vacuum hose. on a side not if you have an almost empty fuel tank and the z has sat for a week fill the tank or you will kick yourself to death before she starts., one other option that I have done but I never recommend it is shoot some starting fluid down the intake and it will fire and cause the pump to pick up fuel a lot quicker. back to your original question double check all fuel lines for blocks and then check the vacuum hose and finally check the pump diaphragm. also double check the petcock valve for crud as well ran into that once. Good luck and let us know what you find there are fuel pump rebuild kits out there.

[King Trikester]

Ok thanks she fires up first of second kick everytime, a vacuum leak could be possible I will have to go through the fuel system, it will get me better aquainted the thre old girl, thank you I will let you know how I make out.

[Just-Tri-It]

"It ran really great all day and at the end of the day it started bogging and dying out."

This is a long shot and over obvious but are you running low in gas and just need to use Reserve or refill? Of course on a new rebuild it could be other issues as well.

[christph]

Check your gas tank breather tube for kinks or obstructions. I recently had this problem with my 86 Z and I suspect there is a kink in the gas tank breather tube--I just haven't had time to inspect it yet. 80% of the time it runs fine, but after long fast runs the fuel stops flowing and the engine cuts out. I rebuilt the pump so that's not the problem. Then I realized it is probably a vacuum being created in the tank, which would explain why it only does it after being run hard. Next time it happens open your gas cap and see if it starts flowing again--it works with mine. I think the breather tube for the tank is small in diameter and long, which creates the problem. I haven't had a chance to test my theory yet but I plan on getting a larger breather tube.

[King Trikester]

Check your gas tank breather tube for kinks or obstructions. I recently had this problem with my 86 Z and I suspect there is a kink in the gas tank breather tube--I just haven't had time to inspect it yet. 80% of the time it runs fine, but after long fast runs the fuel stops flowing and the engine cuts out. I rebuilt the pump so that's not the problem. Then I realized it is probably a vacuum being created in the tank, which would explain why it only does it after being run hard. Next time it happens open your gas cap and see if it starts flowing again--it works with mine. I think the breather tube for the tank is small in diameter and long, which creates the problem. I haven't had a chance to test my theory yet but I plan on getting a larger breather tube.

Thank you, you just saved me the cost of a carb and fuel pump rebuild kit, I just read your post and went and checked out your theory, you were right, vent line was pinched underneath the fenders directly under all my weight.

It's to dark right now to ride it but I will be itching all day at work to run it and be 100% sure, but it makes perfect sense. I was riding all day with that 84 200es, taking it easy on the fresh top end and waiting for him, it didn't die on me until I was out on my own running her hard pulling lots of vacuum. Thank you again, now I can put the money towards more important things like front breaks and fork seals