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Engine runs rough and cat converter is glowing red


smudvapor

Well-Known Member
Supporting Member
U.S. Military - Veteran
Joined
May 13, 2008
Messages
180
Age
57
City
Youngstown, Ohio
Vehicle Year
1988
Engine
2.9 V6
Transmission
Manual
My credo
"Lets stop thinking in terms of limitations and start thinking in terms of possibilities."
I have an 88 Ranger 2.9 that has been sitting in my garage for about 16 months. It ran fine when we parked it. Now it has a hard time starting and when it does it seems like only about half of the cylinders are firing. I finally got it to idle but after a while the cat converter started getting hot so I turned it off. When might be causing all of this?
 
Cat getting hot means too much unburned fuel is getting into Cat and it is burning it, so........gets very hot.

A misfire means fuel wasn't burned, so the misfires are the cause of Cat getting hot.

Now what is causing the misfires?

Sitting for that long the gasoline in the fuel rail and injectors could have turned to varnish so has clogged up the fuel system, the gas in the tank would be about 40 octane, lol, so wouldn't burn to well.

Gasoline evaporates fairly fast, so always best to drain the system before storing, i.e. start engine, then pull fuel pump fuse/or relay, engine will start to stall but burn up most of the remaining fuel in the system.
Then fill up the gas tank to the top, so as little air as possible is in the gas tank and put cap on, but draining tank is not a bad idea, it if will sit longer than 6 months or so.
 
Cat getting hot means too much unburned fuel is getting into Cat and it is burning it, so........gets very hot.

A misfire means fuel wasn't burned, so the misfires are the cause of Cat getting hot.

Now what is causing the misfires?

Sitting for that long the gasoline in the fuel rail and injectors could have turned to varnish so has clogged up the fuel system, the gas in the tank would be about 40 octane, lol, so wouldn't burn to well.

Gasoline evaporates fairly fast, so always best to drain the system before storing, i.e. start engine, then pull fuel pump fuse/or relay, engine will start to stall but burn up most of the remaining fuel in the system.
Then fill up the gas tank to the top, so as little air as possible is in the gas tank and put cap on, but draining tank is not a bad idea, it if will sit longer than 6 months or so.

Ron: What about dropping in some octane boost and fuel line cleaner along with the fresh tank of gas? I've often wondered about doing this for long term projects (ie: family tractor not being used all winter...etc...)

S-
 
Cat getting hot means too much unburned fuel is getting into Cat and it is burning it, so........gets very hot.

A misfire means fuel wasn't burned, so the misfires are the cause of Cat getting hot.

Now what is causing the misfires?

Sitting for that long the gasoline in the fuel rail and injectors could have turned to varnish so has clogged up the fuel system, the gas in the tank would be about 40 octane, lol, so wouldn't burn to well.

Gasoline evaporates fairly fast, so always best to drain the system before storing, i.e. start engine, then pull fuel pump fuse/or relay, engine will start to stall but burn up most of the remaining fuel in the system.
Then fill up the gas tank to the top, so as little air as possible is in the gas tank and put cap on, but draining tank is not a bad idea, it if will sit longer than 6 months or so.


How am I going to get the system cleaned out? I replaced all of the spark plugs and tried it again and it is the same. It will run but I have to keep my foot in it. It sounds like only a couple of cylinders are firing.
 
How much old gas is in the tank?

Can you siphon some/most out and replace it with new gas?
Put some Seafoam in the gas tank with the new gas


Just to test if all fuel injectors are working, not clogged.
Pull coil wire to distributor, so no spark
Crank engine a few times.
Pull spark plugs, each one should be wet with fuel, dry plug means injector is clogged.
Smell the wet plug, bad gas will smell funny.


Yes you can add an octane boost but what it is really for is to absorb water that has settle in the bottom of the tank.
It is an ethanol product, ethanol raises octane level
 
Last edited:
A weak coil did it on my'84 Grand Wagoneer.. If all six plugs are black. There also could be a rodent nest in the exhaust. Please post back with the fix
 
How much old gas is in the tank?

Can you siphon some/most out and replace it with new gas?
Put some Seafoam in the gas tank with the new gas


Just to test if all fuel injectors are working, not clogged.
Pull coil wire to distributor, so no spark
Crank engine a few times.
Pull spark plugs, each one should be wet with fuel, dry plug means injector is clogged.
Smell the wet plug, bad gas will smell funny.


Yes you can add an octane boost but what it is really for is to absorb water that has settle in the bottom of the tank.
It is an ethanol product, ethanol raises octane level

I siphoned about five gallons out of the tank. I figured if the water was at the bottom that might be enough. I tried to fire it up and at first it did the same as it was doing before and then it just took off and started running just fine. I think you were right. There was water in the gas. I will try it again in the morning but I think if I put another five gallons of fresh gas in there it will be just fine. Thanks for you help!:icon_thumby:
 
I would think a can of dry gas which I think is mostly alcohol and a full tank. Run it out and then change the fuel filter would be a good idea.
 

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