Slight hesitation when you accelerate/ also backfires

[leidgam]

Hello guys,

I have this problem with a vehicle that I just imported for a client. It's a 1970 L60 short wheel base soft top.

When you first step on the gas, in the beginning there is a slight hesitation, like it wants to turn off. If you step on it harder it will recover. It seems to do it more often when the engine is cold, as it warms up it still does it but a lot less. And also sometimes it will backfire.

I'm pretty sure it's related to the carburetor. Any suggestions as to what I should adjust or clean?

Also I'm not a big fan of the fuel filter happiness going on with the Patrols in Colombia sometimes. They like to install multiple fuel filters along the way. I'm going to try to clean it up a bit, install one new filter and straighten up the lines. They have too many curves because they have too many filters.

Any other suggestions are welcomed.

Here are some pictures for your viewing pleasure:

IMG-20181116-WA0006.jpg

IMG-20181117-WA0015.jpg

IMG-20181117-WA0016.jpg

[RiverPatrol]

That's a beautiful Patrol! Is it one of Volcan's? Yeah, full filter placement is wrong on so many levels.

The first thing that comes to mind on the hesitation is the accelerator pump in the carb. That usually requires and overhaul to include replacing the pump. You'd need to source the kit out of Colombia, that carb was never available here.

[Esteban]

Beautiful pictures and setup.

In addition to RiverPatrol's comments, please take a look at this thread:

http://www.60patrol.com/forum/viewtopic ... 0&start=15

Member Pancho has some good photos there. On the side of the carb, you'll see that the accelerator pump is driven by a plastic cam that is on the outside. This cam wears often and the carb develops a flat spot. It might be difficult to source a spare cam, but making a metal one could be done with lots of patience. When you initially give gas, the throttle opens but there's no response from the accelerator pump due to the wear of the cam, and the engine hesitates.

Hope this is your problem.

[leidgam]

That's a beautiful Patrol! Is it one of Volcan's? Yeah, full filter placement is wrong on so many levels.

The first thing that comes to mind on the hesitation is the accelerator pump in the carb. That usually requires and overhaul to include replacing the pump. You'd need to source the kit out of Colombia, that carb was never available here.

Thanks for the compliment, Volcan has very nice vehicles. We also source Patrols and Land Cruisers out of Colombia and this is one we helped a client bring.

I hope to be able to get my own Patrol someday, right now we are still adapting to having a newborn son so I need the income. He eats a lot and diapers are expensive I do actually like the Patrols better than the FJ40s, but they are both excellent vehicles. I get more people stop and ask when I'm driving the Patrol.

Thanks again for the suggestions!

[leidgam]

Beautiful pictures and setup.

In addition to RiverPatrol's comments, please take a look at this thread:

http://www.60patrol.com/forum/viewtopic ... 0&start=15

Member Pancho has some good photos there. On the side of the carb, you'll see that the accelerator pump is driven by a plastic cam that is on the outside. This cam wears often and the carb develops a flat spot. It might be difficult to source a spare cam, but making a metal one could be done with lots of patience. When you initially give gas, the throttle opens but there's no response from the accelerator pump due to the wear of the cam, and the engine hesitates.

Hope this is your problem.

Thank you so much, I have fun photographing these trucks.

Also, thank you for your help. It makes sense. I will check on this and let you know the results.

[leidgam]

I have an update, and it's worse.

Now I think the carb is over-flooding. It will crank and run rough when its cold, but as soon as it starts to warm up, it will shut off.
Once it shuts off, I see fuel spilling over the side of the carburetor over the intake manifold. I guess these things have an overfill hole, if it gets too full, it spews it out. Not sure, but just taking a wild guess. I was asking around and people say it could be a float. Any suggestions or recommendations of what should I try to do? Very much appreciated. Thank you for your patience.

[mad4hws]

Not sure if this will help. My Patrol was also imported from Columbia. It has a Hitatchi VHA carb. It was running okay, but I decided to take it off and have it rebuilt anyway - just because i was going through the entire fuel system. I sent it off to Carburetor Specialists in Alpharetta GA and they were able to completely rebuild it. It took about 3 weeks. I can't tell you how it runs yet because my gas tank is not yet re-installed after being cleaned. I have high hopes for it though. They also had some replacement alternatives. If you want to call them, here's their contact info:

WWW.CARBS.US
888-871-CARB

[Esteban]

...Now I think the carb is over-flooding. It will crank and run rough when its cold, but as soon as it starts to warm up, it will shut off.
Once it shuts off, I see fuel spilling over the side of the carburetor over the intake manifold. I guess these things have an overfill hole, if it gets too full, it spews it out. Not sure, but just taking a wild guess. I was asking around and people say it could be a float. Any suggestions or recommendations of what should I try to do? Very much appreciated. Thank you for your patience.

Rather than the float, it could be the float valve/needle that is getting stuck in the open position, but of course it is a float related issue.

The valve/needle is accessible from the outside, so you can take it out and inspect. Could be some debris preventing proper seating of the needle.

[leidgam]

Thank you Esteban, you and River Patrol are a wealth of knowledge.
When you have a chance, could you tell me which is the needle referencing the parts manual? I'm young to work on these carburetors, everything I've known is fuel injected.

[Esteban]

The Needle Valve Body is #14 in the following diagram. The body is screwed from the outside of the carb in the location shown in the inset photo. At one end of the Needle Valve Body you have the "Needle" itself (this is the name it's commonly known). The float makes contact with it allowing or blocking flow of fuel into the carb.

You can clean all the components and then try blowing some air with your mouth inside by the outside end while you work the needle on the other side, checking whether the needle is actually sealing or not. Don't use compressed air for this "test" since the needle can come loose and flying to be never be found .

Carburetor VHA Parts.jpg