75 FJ - Trouble starting when warm (1 Viewer)

[Navenarb70]

Hi All,

Recently I've been having trouble starting my FJ after it's been running for a while. I have no problem starting it when it's cold - first start of the day...no problem....starts right up. If I drive for 20 minutes then shut if off and try to restart it, it struggles. It's trying to turn over (whah whah whah whah), but just doesn't start. Same behavior whether or not the choke is in our out.

It starts eventually, but idles really rough. Any suggestions on what to look at first?

Thanks

 

[brian]

would be handy to know the set up is??
stock? desmogged? what carb?
v8?

 

[Navenarb70]

would be handy to know the set up is??
stock? desmogged? what carb?
v8?

Completely stock 2F with Carb. Was rebuilt back in 2014. Not sure about the desmogged.

 

[Navenarb70]

And let me add that this is my first FJ...just got it about a month ago. Could I be letting it "warm up" too long with the choke out (or half choked)? I usually start it and let it run for about 5 minutes with the choke at half pull. Not sure if that makes any difference, but figured I'd put it out there.

 

[handcannon]

I'm assuming that you are not very familiar with a carb. It would really help us to know some specifics about the motor. It is a 75, but is it a stock motor or ?, stock carb or aftermarket, smogged or desmogged, if stock carb is there fuel showing in the sight glass, does it have a working carb cooling fan (not sure what year they started installing them)?

First, the amount of choke, and the length of time needed will vary depending on outside temperature, and the peculiarities of the vehicle. Five minutes at half choke may, or may not, be too long. It will just take some experimenting. The main thing that too long with the choke on will cause is carboning up the plugs, valves, and combustion chamber. This carboning should be blown out within the first few miles. This amount of choke will not affect any subsequent start attempts, unless the motor is shut down when the choke is still on. What may happen at that time is the motor may act like it is getting too much gas, start with a rough idle, and blow black smoke. At this point, if the choke is immediately released, the motor should smooth out shortly.

Second, there are several possibilities for the cause of the problem. If stock carb, is there fuel showing in the sight glass when trying to restart a warm motor? It may be that a warm motor is boiling out the gas from the float bowl, requiring the starter to bring fuel back up to the carb. If this is the case the motor will most likely start the same as one that was ran out of gas, rough and stumbling until enough gas is pumped up into the carb. It could also be electrical/timing. It could be more that one problem affecting the restart.

When trying to find the problem do just one thing at a time. That way you will know the cause of your problem. Add some of this needed info and keep checking back. This website is loaded with people who are very helpful, they just need to know details.

Don

Opps, just noticed that you had posted it was a stock 2F motor. But, most of my questions still apply. Add some pics of what you have. The motor, and of course the 40.

 

[Sethro60]

Try no choke, gas floored until it fires. A few revs and your good to go. Works every time for me.

 

[emac]

I have experienced longer hot starts on occasion. Especially if I forget to give it some gas while starting. Having grown up with carbs, you always added gas when starting. Then we went to FI and zero gas at start up. Now when I drive one of my carb cars I have to remember to add some fuel when starting. Try starting with different amounts of gas pedal when hot, you may find the sweet spot it likes. I dont have any carb motors that start as easy as a modern FI motor. Hot or cold.

 

[Navenarb70]

I'm assuming that you are not very familiar with a carb. It would really help us to know some specifics about the motor. It is a 75, but is it a stock motor or ?, stock carb or aftermarket, smogged or desmogged, if stock carb is there fuel showing in the sight glass, does it have a working carb cooling fan (not sure what year they started installing them)?

First, the amount of choke, and the length of time needed will vary depending on outside temperature, and the peculiarities of the vehicle. Five minutes at half choke may, or may not, be too long. It will just take some experimenting. The main thing that too long with the choke on will cause is carboning up the plugs, valves, and combustion chamber. This carboning should be blown out within the first few miles. This amount of choke will not affect any subsequent start attempts, unless the motor is shut down when the choke is still on. What may happen at that time is the motor may act like it is getting too much gas, start with a rough idle, and blow black smoke. At this point, if the choke is immediately released, the motor should smooth out shortly.

Second, there are several possibilities for the cause of the problem. If stock carb, is there fuel showing in the sight glass when trying to restart a warm motor? It may be that a warm motor is boiling out the gas from the float bowl, requiring the starter to bring fuel back up to the carb. If this is the case the motor will most likely start the same as one that was ran out of gas, rough and stumbling until enough gas is pumped up into the carb. It could also be electrical/timing. It could be more that one problem affecting the restart.

When trying to find the problem do just one thing at a time. That way you will know the cause of your problem. Add some of this needed info and keep checking back. This website is loaded with people who are very helpful, they just need to know details.

Don

Opps, just noticed that you had posted it was a stock 2F motor. But, most of my questions still apply. Add some pics of what you have. The motor, and of course the 40.

Thanks for all the info (and your patience). It has a stock carb and there is gas in the sight glass. I just started it after a couple hours of downtime and it started right up and ran perfectly.

Maybe this is just a matter of me getting used to a car with a carb & adjusting my choke & starting method. I'll post any updates going forward. Thanks again.

 

[emac]

Habits can be hard to break. On my rig a cold start is: Full choke, two pumps of gas and as soon as it fires go to half choke. as soon as it gets going I turn the choke off. By the time I get out of the neighborhood (1 mile) it is usually pretty good. Sometimes I have to feather the choke to get it right for the first few miles. Bottom line for me is to get the choke off sooner than later. I am not the type that starts a car and lets it fully warm up before moving it. Once oil pressure is up, I go. Unless it has been sitting for a long time. Hot start put enough fuel in to get it to fire.

 

[Navenarb70]

Habits can be hard to break. On my rig a cold start is: Full choke, two pumps of gas and as soon as it fires go to half choke. as soon as it gets going I turn the choke off. By the time I get out of the neighborhood (1 mile) it is usually pretty good. Sometimes I have to feather the choke to get it right for the first few miles. Bottom line for me is to get the choke off sooner than later. I am not the type that starts a car and lets it fully warm up before moving it. Once oil pressure is up, I go. Unless it has been sitting for a long time. Hot start put enough fuel in to get it to fire.

Thanks emac. I appreciate the info.