Hello, I have an 87 b150 with the /6.

I recently swapped over a good condition low mileage holley 1945 for the wore out one on my van.

I fired it up and it ran better than it ever has since I bought it.

It turned out to be a nice day today so I fired it up again and started checking all my vaccuum lines and such. Everything seemed fine until I noticed the exhaust was glowing cherry red.

I'm assuming this is not normal. What would cause this????

It may have been happening with the old carb I just never noticed it before.

Maybe your running it too lean. Are you running a cat? Air pump and EGR attached? Carb rebuilt/reman?

Either Way lean, or Way rich. Way rich you would smell, and likely burn your eyes. So unless your eyes are watering, it is probably lean. Ajust air fuel, and it might require jetting and timing changes.

Yes I am running a cat.
The air pump and egr are attached and working.
The carb is from a running but wrecked low mileage 87 b150 /6.


I will check to see if the exhaust burns my eyes or not. I saw the pipe was red hot so I shut it down right away.

u dont have to put your eyes in the exhaust for them to burn, cuz theyll prolly burn if you put them there no matter wut. my ol 77 cherokee is the driver seat eye burner right now, i need to tune the hell out of is richness

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'72 Valiant DD for over a decade-225-Disc brakes, big T-bars, big Sway bars f/r, carter bbd/super six, GM HEI, 2- 12" subs in trunk, 1000w amp...
'77 cherokee cheif widetrack-360-33x12.5 tires-no lift. keeps driveway dry-project/backup DD/mudder

There is also a good chance the convertor is stopped up if you had carb problems before. I have never seen a slant six cherry the pipes from being to lean or any other condission but I expect having the convertor in the exhaust could make a small condision worse than it would normally be. If the convertor is working it can also burn a lot of extra fuel if its to rich and you may not be able to tell its rich.


A vacuum check could help in figuring out if the convertor is stopped up, it will loose vacuum.


Very late ignition timing would be something I would look for also.




Jess

That made me laugh, sorry.

Would a sticking choke linkage cause it to run rich enough to cause this???

Which part of the exhaust is glowing red?

Rich running will heat up the catalytic converter and make it grow red hot.

Lean running will heat up the exhaust manifold and headpipe and make them grow red hot.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Which part of the exhaust is glowing red?


Both of the catalytic converters and the pipe that connects them.

OK, this means you're dumping grossly excessive unburned fuel out the exhaust. It could be due to a carburetion or choke problem, it could be due to ignition misfiring (at this point, if carb/choke problems are at the root of the problem, your spark plugs will be badly fouled, so it'll be "both"). If the converters have got hot enough to glow from the outside, they have likely both melted down internally, creating tremendous exhaust restriction and greatly aggravating the problem. So, you have a couple of tasks ahead of you:

1) Find out what's causing all the raw fuel to go out the exhaust. Fix all causes.

2) New catalytic converter(s). You can do considerably better for considerably less money than the factory "pre-cat/main-cat" setup with today's converters. See this post. Do make sure your truck's air injection system is working correctly!

One more question: Did this '87 originally have an Oxygen sensor screwed into the rear wall of the central collector of the exhaust manifold? If so, it was originally equipped with a Holley 6145, which is a feedback-equipped #1945 with duty cycle solenoid. A regular #1945 would tend to cook the cats in such an application...

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

The question of if the van had the correct carb on it was one that I had after I bought it and went to tune it up. The haynes and chiltons kept referring to a feedback carb 6145 but this van didn't have one. Then I picked up a FSM and read that models built in Canada came with the 1945 and no o2 sensor.

Since I freed up the choke linkage I cannot get the cats to glow no matter what I try so hopefully that is what it was but I will be keeping an eye on it for sure.

Thanks for all the replies.

I am just jumping in on this thread because it makes me think of my childhood. Sorry I can't actually help.

On the farm we powered one of our irrigation systems with a 318 on LPG. It was a 1/2 section circle system. If it was windy, we couldn't actually hear if it was running but at night we could see the manifolds glow with binoculars!!! That engine ran my entire childhood (many times 24 hrs a day at a high RPM) and then some, we actually sold it a few years ago at an auction.
I do remember it being one of my first "assisted" rebuilds with my dad and I really don't remember him rebuilding it after that (late 80's) so why did it perform so well and last so long when this engine is in trouble?

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