• Hello Guest, we are proud to now have our Wiki online that is completely compiled and written by our members. Feel free to browse our Jeep-CJ Wiki or click on any orange keyword when looking at posts in the forum.

Engine Fuel squirting out spark plug port

Engine Fuel squirting out spark plug port

Detheridge

Jeeper
Posts
5
Thanks
0
Location
Gardnerville, NV, USA
Vehicle(s)
78 CJ5 304, T18, D20, AMC 20 converted to one pc axle, 4.56 gears, D30 front, 4.56 gears, ARB locker
Working on a 78 CJ5 AMC 304 w/Holley 4bbl 1850.
Fuel is squirting out the #8 (maybe #6 too) spark plug port and mixing with the engine oil.
The jeep sat for 2 years after an engine fire. I have repaired visible damage and rebuilt the carb. I have had to change the oil twice due to gas pouring into the crankcase.

Suggestions?
Thanks
 
  1. Do you have an electric or mechanical pump?
  2. Holley 1850 is a side hung float. Does fuel flow out of the sight plug when cranking? If so the needle may be opened by too much pressure.
  3. Fuel in the oil could be from flooded cylinder walls allowing the gas to get past the rings. Have you run a compression check?
  4. 8 and 6 are adjacent cyl.'s Did the fire harm the intake gasket? It's a steal valley pan gasket so I doubt it.
I'm mostly concerned with 1 & 2.
I definitely would disconnect the fuel line to the carb and run it until it runs out of fuel and start a fresh diagnosis.
 
Risking derision I must ask, are the spark plugs installed? Or is the gas going past the intake valve/rings to crank case? 🔭
 
I have an electric fuel pump. I adjusted the floats until the fuel splashed out the inspection ports when I jostled the jeep. Since it's electric I could adjust the floats with just the pump running since I can't start it yet. I ran a compression check, and all cylinders are between 125 and 140. The fire was put out pretty quickly and only damaged stuff on top. Wiring, tubing, distributor cap, etc..

I'm talking a lot of fuel is squirting out the spark plug port and it fills up fast. Before the fire the jeep ran pretty well so I kind of doubt it's an issue with the valves or the rings, at least not enough to cause this. It looks like more fuel than would collect on a dead cylinder. Something is causing fuel to flow unrestricted through the carb and it's not the float level.

And yes the plug was removed when I witnessed the fuel squirting out.

I'm going to blow out my fuel lines and replace the 3 pipe fuel filter. Maybe the return line is clogged. Any ideas?

Thanks
 
Risking derision I must ask, are the spark plugs installed? Or is the gas going past the intake valve/rings to crank case? 🔭
Hello,
Fuel is filling up the crank case. So, it must be flowing past the valves and rings, but what is causing fuel to leak unrestricted into the intake manifold. It really dumps fuel when I am able to get it started. Runs ok at first and quickly gets worse. When you shut it down you can hear gas dripping into the crankcase. Of course, until I solve the gas leak, I can't run it to help diagnose the issue without causing internal damage if I haven't already.
 
The carburator cannot control fuel delivery due to malfunction or there is excessive fuel pressure.
 
I woil
I rebuilt the carb. I must have done something wrong. I'll pull it and start over. Any ideas what I may have done wrong?
Before I would take the carb apart, I would pull it but leave the fuel line on.
Then turn on the pump while being able to look at the bottom of the carb.

I did not see what the fuel pressure is set to but any more than 7 or 8 psi can blow past the needle valve.

But a blown power valve will also dump fuel like crazy but it only supplies fuel to the main circuit, but the main circuit is not supposed to be active at idle. Do you have another power valve?
 
I rebuilt the carb. I must have done something wrong. I'll pull it and start over. Any ideas what I may have done wrong?
slow down the fuel pressure, buy a regulator, most carbs don't need more than 5 psi. Been there once with my 75 IHC truck too much carb and 9 psi pump, less carb and 5 psi was the cure
 

Jeep-CJ Donation Drive

Help support Jeep-CJ.com by making a contribution.

Help support Jeep-CJ.com by making a contribution.
Goal
$200.00
Earned
$0.00
This donation drive ends in
0 hours, 0 minutes, 0 seconds
  0.0%
Back
Top Bottom