Idles great, runs like crap-pg. 2

[67bondobronc]

Specs: 302, pretty much stock everything except a small edelbrock 4-bar. The Bronco idles great but when I start to drive it the motor begins to sputter, cut-out and sometimes shuts off when I give it gas. I thought that I had the gas lines ran too close to the exhaust so I re-did those and it is still doing it. I put in a clear fuel filter to see if there was any gunk coming out of the gas tank and that is not it. It is getting gas but:

1) Should the fuel filter be completely full? It is only half full and will not completely fill up so I am thinking that it is not getting enough gas. So, that could mean a clogged sending unit or bad fuel pump? How do I check those?

2) Or is it something else that I am overlooking?

Thanks as always

 

[SeaBiscuit68]

1) Mostly full is normal.

2) How old are the plug wires? Aged ones can exhibit that symptom.

 

[67bondobronc]

Pretty new spark plug wires but I think they were too close to the headers and I fixed that but I wonder if they were damaged before I fixed it.

 

[KempEl]

when was the last time you rebuilt the carb. try carb cleaner and new air filter

 

[Skiddy]

If your still running points they could exhibit that kind of behavior also.

 

[67bondobronc]

Thanks for the replies.
The carb is a "reman" from Summit.

I am running points, I will check the gap to see if it is correct.

I have been searching past posts and some with the same problem had to rebuild the carb.

This may help, I could swear that when it starts sputtering (when I put it in gear and press the gas) it almost sounded like it had a quiet backfire. When it is in neutral I can rev it up and it does fine. The timing is close to being perfect (I battled that problem for months).

One other thing...........please remember that I have been doing a frame off for four years and in the middle of this I built a new home and had to move and store it and move it again. During one of the moves I was loading the Bronco and the fan loosened and ate up a radiator and I did not have an air cleaner on it (I should have a camera crew documenting my rebuild, it would be great comedy). Maybe junk got in it. But, it was running fine on my little test runs until the other day.

 

[SeaBiscuit68]

Hard for me to say if you damaged them. Burnt marks?

Or it could be the carb. Sounds like the idle circuit is clean and maybe the running circuit is dirty.

 

[302fix]

Sounds a little like bad gas. It's shelf life is pretty short anymore.

If you're sure the gas is fine then I'd look at the points and vacuum advance.

I swithced to the pertronix setup and it made a world of difference.

Good luck.

 

[Skuzzlebutt]

Is the vacuum advance connected to a proper vac source?

 

[Mr Joe]

It sounds like a fuel issue... low fuel pressure, poor flow, low float setting.

I'd first check the fuel pressure with a gauge. It should be between 4-7 psi.

 

[67bondobronc]

Is the vacuum advance connected to a proper vac source?

On the carb I have there are two places to hook a vac line to, I have mine on the right as you are looking at the carb, there is one on the left also but I have that one plugged.

I'd first check the fuel pressure with a gauge. It should be between 4-7 psi.

I will need to get a pressure gauge to check that one.

If you're sure the gas is fine then I'd look at the points and vacuum advance.

I am going to check the gap on the points this afternoon.

I will check all of these and then report back my results..........wish me luck.

 

[RangerRob]

I think you are hooked up to the wrong vacuum source at the carb. Pretty sure the one on the left as you are looking from the front is the ported vacuum. You should hook up to that one and cap the other one off. You might need to set the timing again.

Good Luck!!!

Rob

 

[wildbill]

If it dose this when you try to give it the gas then I would look at the accelerator pump as if it is not putting out it will crap out on you good luck. Bill %) ;D

 

[B1]

If it dose this when you try to give it the gas then I would look at the accelerator pump as if it is not putting out it will crap out on you good luck. Bill %) ;D

X2 have had this happen before.

 

[67bondobronc]

Things I did this afternoon;

Points gap is good
Checked wires for defects Spark Plug wires are good
Vaccum advance connected to the correct place
Couldn't check fuel pressure but I do have a clear filter and it looks like it is pumping good
Pulled valved covers and checked for loose rocker......none found.
Pulled the top of the edelbrock off and sprayed the mess out of it wtih carb cleaner.
Checked to make sure both jets are spraying good.

One thing I noticed is that when I give it gas it sounds like it is sucking air hard........sorta like my engine is having an asthma attack??????

If it dose this when you try to give it the gas then I would look at the accelerator pump as if it is not putting out it will crap out on you good luck. Bill

Lost me on this one........would that be in the carb?

What about an exhaust leak? Could this be a cause and if so, any easy way to check for one?

Thanks again for all the replies, I greatly appreciate it.

 

[abromer]

The exact same thing happened to me and I still have not been able to fully fix the problem. I rebuilt my carb, new fuel pump, fuel lines, filter, fuel cell, timing, plugs, cap, wires and i still cant figure this out. It was running perfect one day and the next day the problem started. Thanks for opening this thread, i will keep reading in hope of fixing both our problems.

Aaron

 

[Wes harden]

Ok with the engine off air cleaner remove look down the carb bore primary barrels and open the throttle full, you should see a squirt of gas in both barrels. If not your accelerator pump is working. If you think you have gunked up passages in the carb start the engine bring revs up to @ 2500 and close the choke vavle/butterfly by hand, don't let the engine die. This will create a high vacuum in the carb and may dislodge any blockage.

 

[67bondobronc]

Ok with the engine off air cleaner remove look down the carb bore primary barrels and open the throttle full, you should see a squirt of gas in both barrels. If not your accelerator pump is working.

I did this and saw the two squirts (streams) of gas, so this means mine is working correct?

Also, I had a restless night and it came to me that while I was fighting my timing problem I was smoking out the tail pipes like crazy and I wonder if I damaged the spark plugs. I probably have burnt them or they have junk on them. So I think this would cause problems. I am getting new plugs this afternoon and trying that.

But, I can't get the sound the carb makes when I give it gas..........seriously sucking. Break it down simply.........gas, air, fire............should run. So why is it wanting so much air?

Thanks again......................I am determined to beat this.

 

[67bondobronc]

Day 3
Reset the timing
Changed all the spark plugs.......the others had black crap that I could scrape off
Still runs like crap
Blue/white/grey smoke coming out of right side.


When I hit the gas it just stalls.

Two weeks ago and this was not happening.
I have done all suggestions (I think) except pressure tested the gas line and I didn't want to spend the money on the gauge but it looks like that is the last choice.

Any ideas?

 

[DonsBolt]

It still sounds like you are having a carb problem.

Maybee there is someone that lives close to you that has a good working carb they can lend you. Since it only take a few minutes to swap carbs, I might try that first.

If I wasn't so far away I would lend you a carb I have that I know is perfect.
Maybee someone close to you will let you try there carb.

If that doesn't solve your problem, that would rule out the carb, if it fixes it you know your problem.

I have a pertronix ignitor II and one of there coils. If you want them just pay me shipping and there yours. That would elliminate any issues the points may be causing you.