Starting problems - Chugs for 10 seconds, starts, stall, then start right up.

[Flex BT]

My jeep has the following problem starting:

If it hasn't been started in a few days it will crank for a long time (approx 10 seconds) then start. The sound of the starter is very strong and it sounds like it should be turning over right away. After it finally starts I turn the key back to the run position and it will stall. It starts right up after that and always starts right up when it is warm or has been driven in the last several hours. In the last few months I've done several upgrades and I'm not sure when the problem started. I know it was happening before I replaced the carburetor. It also has a new teamrush upgrade with new diz cap, wires and plugs, new fuel filter, and fuel reg (set to 3.5 per Weber specs). Any ideas?

 

[Saddle Tramp]

The symptom described typically signals a carburetor bowl that drains out while sitting then it takes a little time to replenish the gas to the bowl. From my experience Webers are either good right out of the box or they are junk, you just never know. However assuming you got a good one the problem may be the fuel pump. If it is mechanical and starting to fail but just starting to fail it could takes a little time to get the fuel flowing after sitting for a few days. If you haven’t change the pump spend a few bucks and just do it.

 

[hole]

It does sound like a fuel delivery issue. What fuel pump are you using, elec or mechanical?

 

[jasonmark1993]

I agree with the prior two responses and would start looking at that.

When you would normally expect the stall to happen, pop the air cleaner and manually work the throttle while looking into the carb. If you have no fuel, you just have to figure out why.

 

[Flex BT]

It does sound like a fuel delivery issue. What fuel pump are you using, elec or mechanical?

The stock mechanical one, I don't know if it has ever been replaced but it looks like it. Which should I get as a replacement? It will have a fuel pressure regulator in between it and the carb.

 

[hole]

Hopefully someone with any Weber experience can join in, because I don't know anything about them. That said, I would look at the pump.Your fuel is draining back to the tank after sitting for only a few days, causing the hard start. As far as which pump to run, I would run mechanical on carburated vehicals and electric on injected. Electric pumps don't like to suck fuel, they like to push it and should generally be mounted close to the tank. Mechanical pumps do a better job of sucking fuel but don't push it as well. The cost for a quality mech vs electric will be quite lower too.

 

[gmakra]

Whats the temperature when your having these problems?
The I-6 manifold has a problem with fuel puddling on the bottom of the manifold when it gets cold. Thats why there is a hedgehog or electric heater in the bottom of the stock manifold it helps keep the fuel in suspension, that is also why the manifold is heated with engine coolant.

Take a look at the hedgehog and see if the connector fell off or your relay is working.

 

[Flex BT]

All temperatures, same issue. I put in a new pump today, I'll let you know how it goes. I know there's a hedgehog under the carb inside the manifold, I thought that was just to agitate the air / fuel mix coming through. What connector are you referring to?

 

[Flex BT]

Still the same problem with the new fuel pump. How can I check the carb, and what connector in the intake manifold were you talking about gmakra? Would the heater start working fast enough to make it a problem right at startup? I thought the manifold was just heated by radiator fluid.

 

[gmakra]

Underneath the manifold there will be a flag terminal that should have a 12 gage wire going to the hedgehog. This red wire should go to a relay sommwhere around the fire fall by the mainfold side of the engine bay. This hedgehog is controlled by the engine temp.

 

[Flex BT]

Well I gave it a peek today. A very short fray of wires coming from the bottom of the intake heater. Maybe enough to patch up but I'm not sure. I saw the relay is for sale, I can just buy that and connect it to the oil gauge, battery, manifold sensor and intake heater? There was no trace of and of the old wires or relay. The PO probably removed it completely while doing the painless wiring harness he installed.

My other question is could this really affect the start up time? It seems like it would take a lot longer than just a few turns of the starter for the hedgehog to heat up enough to make a difference in the start time. Does it really help the fuel atomize that quickly?

 

[Dwilder]

I had an issue where i had to pour gas into the carb, then it would run fine. Did most all the checks and then i use a bike pump to put pressure on the gas tank, wrap a rag around it and make a seal, and pumped pressure to see if i could get gas out of the line feeding the mech gas pump up front. Found the gas draining out on top of the tank. The rubber hose had a hole at the connection on the tank. Its hard to draw fuel thru a broken straw...

Dropped the tank, replaced the soft rubber hoses, and that fixed the issue.

I also had to replace the tank and the sending unit due to rust and age, but thats a different story

 

[Torxhead]

Flex, I think you have other issues than a manifold heater that might not work. Since you have installed a new fuel pump have you verified that it works and that is the issue? A fuel pressure gauge would be one way to check this and you are looking for at least 3.5 p.s.i. You could at least unhook the inlet fuel line and make sure it is pumping gas when you hit the starter. When you do get it started, let it sit for awhile to make sure the float bowl is not loosing any gas by draining out or evaporation from heat.

 

[mtnwhlr]

I had an issue where i had to pour gas into the carb, then it would run fine. Did most all the checks and then i use a bike pump to put pressure on the gas tank, wrap a rag around it and make a seal, and pumped pressure to see if i could get gas out of the line feeding the mech gas pump up front. Found the gas draining out on top of the tank. The rubber hose had a hole at the connection on the tank. Its hard to draw fuel thru a broken straw...

Dropped the tank, replaced the soft rubber hoses, and that fixed the issue.

I also had to replace the tank and the sending unit due to rust and age, but thats a different story

I love this, you had a problem and came up with a ingenious way to find what is wrong. This is what being a Jeeper is all about

 

[Hedgehog]

My suggestion, and I'm not trying to be smart, just learn to live with it. Know that it's going to take a few seconds to start your jeep and that it is perfectly normal for a carbureted vehicle. Think of it as character.

 

[jdcaples]

The PO's weber is sitting around waiting for me to rebuild it. I knew I wouldn't get around to it for quite a while, so I replaced it with one of Gronk's Motorcraft 2150s for now; felt like seeing how the other half lives, so to speak.

Anyway, I pulled the weber because its bowl started going dry after 48, then 24 hours of sitting. For a few weeks I dumped a standard red gas cap's worth of fuel down the throat and it'd start right up and keep running.

At first, I probably cranked the engine a few times as you (original poster) are doing, and I think it stalled, but can't be sure. I do know that it was just easier to prime the carb first.

If you can, look at the bowl and recheck the float level. I'm not sure what it should be set to because I was counting on the rebuild kit to tell me

-Jon

 

[Lumpy Grits]

Are you still using the OEM fuel filter with the return line?
If so-Make sure the return line is at the top, as in a 12 o'clock position.
LG

 

[Flex BT]

The return for the fuel line is oriented on top of the filter. What I thought might be causing an issue is that the filter is lower than my carburetor.

This is an old thread, but the problem is still there. I didn't run the jeep for about 2 weeks and it probably took 20 full seconds of cranking before it finally turned over. I know there's no fuel in the line right before the carb as the fuel pressure gauge I installed is only a few inches before the float bowl and it doesn't move until a few seconds before the motor finally fires.

I think the issue is two parts... the float bowl is evaporating or otherwise emptying out after a few days, and the fuel line is draining over time as well. I think part of my issue might be the fuel filter being lower than the carb, and the other may have to do with the charcoal canister not behaving as it should. That might be responsible for both, who knows. I did the adaptation from the (I think) cherokee canister that's still available that includes drilling out the one port, etc.

Here's my idea for diagnosing where the fuel is running back in the lines... getting clear fuel lines temporarily installed to see where the fuel is backing out of the system. What's the i.d. of the fuel lines between the pump and the carb?

 

[Lumpy Grits]

Raise the filter to the carbs level, if not a bit higher.
LG

 

[Torxhead]

Flex, the fuel intake lines are 5/16" i.d. all the way from the tank. The charcoal canister could create a problem if it is blocking the fuel tank vent system as fuel being pumped out of the tank will create a vacuum in the tank upsetting fuel flow. The fuel tank does need to be vented. Using clear fuel lines sounds like a good idea to check fuel flow.