[HotRodGT]

i drove the car down to autozone last night to get a new serp belt to fit the p/s stuff i installed monday and as soon as i pull in car dies. i didnt think anything of it, got the belt installed and fired her up. it was running really low idle, stumbling on accelaeration, and rich as hell. i limped it home and wasted the next two hour checking timing and carb adjustments and still no solution. i finally gave up when i noticed the cat was glowing red!! i pulled it back in the garage and shaw this black spot

on the ground where the muffler was.

any advice guys? it been a long time since i have messed with carbs

thanks in advance

[69fastback]

Did you check the floats?

[HotRodGT]

no. do you have to pull the metering blocks to do that?

i forgot to mention that it did this to me a couple weeks ago coming home from a buddy and i limped it back but by the time i got home it was running fine.

if the floats stick does that cuase the carb to dump fuel like crazy? how do i check the floats? i feel stupid lol

[jjpluml]

it does sound like the carb to me too. Try runnin some sea foam directly into you fuel inlet hose, let it sit for ab 10 minutes, and then start runnin the fuel to it again and see if it gets any better. Its worked wonders for me quiet a few times without having to bu a full gasket kit and totally tear down the carb

[HotRodGT]

ok i did som research. so the srcrew on top of the two bowls of the carb are to adjust the float levet correct? and the two screws on the side of the bowls would be the sight plugs? so i should empty the bowls, bring the floats as low as the can go, start the car and raise the floats until fuel just start to come out of the sight plug hole?

[HotRodGT]

cant the floats fill up with fuel and basically sink making the carb just keeping pour fuel into the intake?

jeez it been a long time since i messed with carbs...

[MustangMatt96GT]

Personally to me the Glowing red cat, would indicate a lean issue to me and too much timing... You should adjust the floats so that fuel is just dripping out of the plugs on the side...

Then you need to see what jets are in the carb, you may have too small of jets.

And then you need to check the timing, actually would be doing this first IMO...

I see your in Bakersfield, are you an engineer?

[HotRodGT]

thats what i would think about the cat, unless its plugged.

yes im an engineer of sorts

[MustangMatt96GT]

Nice, my sister just got a job out there for upstream oil and gas, she is a chemical engineer.

[69fastback]

Too little timing will raise the EGTs and make the headers glow. A rich condition can cause raw fuel to be dumped in the exhaust and make the headers glow. What carburetor is on it?

[HotRodGT]

Originally Posted by MustangMatt96GT Nice, my sister just got a job out there for upstream oil and gas, she is a chemical engineer.

sweet who does she work for? maybe we can network. i work for a safety firm out here. safety is VERY competitive out here.

Originally Posted by 69fastback Too little timing will raise the EGTs and make the headers glow. A rich condition can cause raw fuel to be dumped in the exhaust and make the headers glow. What carburetor is on it?

its a holley 80457.


i took it all apart tonight and reset the float levels according to the manual i downloaded from holleys website. but i guess i was in a hurry when i re-assembled and i pinched one of the o-ring on the fuel supply rod so when she started up it was spewing fuel everywhere. so i took the rear bowl off and shut it down for the night. luckily i have an ample supply of o-rings at work so maybe tomorrow night i can fire it back up and see whats going on.

[1987mustanggt]

.

[HotRodGT]

rebuilt the carb sunday. i started it this morning and it runs good o far. i still have to adjust it though

[WickedSnake00]

Originally Posted by MustangMatt96GT Personally to me the Glowing red cat, would indicate a lean issue to me and too much timing... I see your in Bakersfield, are you an engineer?

Umm, I could be wrong here, but high temperature faults in cats generally points to excess fuel in the exhaust, so I would guess overly rich? The excess fuel gets cooked off in the catalyst, which produces more heat.

I'm also an engineer in the engine industry, and I've dealt with a fair number of catalyst over-temp faults, usually caused by overly rich commands/overfueling, or incomplete combustion (misfires or low spark).

Clogged cats are also a possibility though.

[HotRodGT]

yea i know i was dumping fuel like crazy due to the soot on the driveway, now i just need to run the car and see it has cleared up since i rebuilt the carb. its hard to tell if im still running rich or if its just blowing out left behind soot from when the carb was jacked up.