75 200 carb and stalling

Hi everyone, I'm new to the forum and IH pickup ownership,

I purchased a running 1975 IH 200 pickup from the great guys at super scouts specialists.

it is a 304 with automatic transmission. it came with a holly 2300 500CFM carb. It was hard to start when cold and stalled often when cold or starting from a stop under light accel. many of the vacc lines were disconnected and there was a aftermarket air cleaner and housing on it.

I swapped out the aftermarket cleaner for a IH one off a Scout that fit the top of the carb, and reconnected the vac lines. Now it starts easy but at idle you can hear a suction 'howling' sound that goes away under accel, but it still stalls a lot under light accell and when i drop it in gear
and ideas/suggestions?

John

Really sounds like another vacuum leak.
Lots of people will tell you to use something flammable like carb cleaner to find it at idle.
Don't. Instead use something non-flammable like a water squirt bottle to hose suspected vacuum leak sites.
If the engine suddenly slows down at idle when water is sprayed on a certain spot, you are close. It should be apparent at that time.
Don't forget carb and EGR base gaskets. PCV hoses and fittings.
Sometimes a intake manifold will crack underneath, too.
Check around intake manifold gaskets.
You can use a piece of garden hose or heater hose placed against your ear to narrow down where the noise is coming from.

The Holley 2300 was/is notorious for the acc. pump going south,usually by a tear in it (is there a gas leak anywhere?) or they just get stretched out and tired. They are just a thin diaphragm with a metal disc in the center,I musta sold 1000 of 'em. My suggestion is rebuild the carb. and eliminate all possible issues within it. Also use a good straight edge and check the fuel bowl for warpage,another common problem.

IH SV8's can be cold running beasts and yours would have had a pre-heat tube going from an exhaust manifold to the air cleaner horn (they do work).

Here' link's to a good carb. parts vendor with manual's and "how to" videos.
http://www.carburetor-parts.com/

2300 parts page
http://www.carburetor-parts.com/2300-Ca ... c_135.html

2300 tech page
http://www.carburetor-parts.com/2300_ep_336.html

There are 2 good overhaul manuals which are free to download.

Forum members who have used Mike's had only good things to say about them.

Had time so I went to the IH parts book.
If original one of the following IH pn's should be stamped on the air horn in addition to the Holley List number.
442165C91
454580C91

The IH carb. kit pn (FWIW)
439441C94

A Google search gave
921 as the Standard Jiffy Kit pn (which I confirmed in the SMP catalog)
which crosses to
CRB 25529 Echlin
http://www.napaonline.com/Catalog/Catal ... 0430106936

Here's the page from Mike's for the carb. by list numbers.
http://www.carburetor-parts.com/Holley- ... p_715.html

Still a good idea to check the List # incase the carb. you have is a replacement.

Torn accel pump causes "sucking, howling noise"?
Don't think so.
Yes, I've replaced my share of those, too.
I think there's a hidden vacuum leak somewhere.
In my shop we'd smoke it, or use a stethoscope to listen for it.
Or we have a small propane bottle connected to a vacuum hose to go around and feed tiny bursts of propane into different places.

Oh..I finally woke up. Torn POWER VALVE. OK. That might do something weird.
Yes, they go bad pretty often.

If I remember right, there are 7 circuits to a carb. Idle and off-idle are just 2 of them. If there is a howling sound, idle has the most vacuum pressure, where as cruising has less vacuum pressure. One possibility is a loose vacuum line. If that can't be found, a hose that is weak might be the culprit. If the truck hasn't had the lines replaced in, oh, say 5 years, why not change them anyway? It won't hurt, it might help, and should increase the reliability of the truck running. I bought a truck from SSS, and used it for a daily driver for more than a year. I've been changing things like that just because they do give out over time. Granted, it's just my 2 cents worth, but I thought it might help. Bill

nadz1126, the Holley Model 2300, List #4412 carb was never used as a factory installation on any IH engine.
This carb, List # 4412 (500 CFM) is mostly used on circle track engines, not IH daily drivers.
A few IH people have made this carb work for them, but either they were carb 'experts' or spent a lot of time tuning, adjusting and trying different carb parts until they got it to run good for them.

A better alternative to the List# 4412 is the Holley Model 2300, list # 7448 (350 CFM) carb, available at Jegs or Summit and some IH vendors as well. It comes as a manual choke carb, but an electric choke module can be purchased and installed on it easily. The List# 7448 carb (350 CFM) is much better suited to the slow revving IH dump truck engines, especially the 304, 345 and 392 engines. There is also a Model 2300 in a 275 CFM which is good for the IH 266 V-8 engine.

You should also get your vacuum hoses in order, fix vacuum leaks, etc. as noted in previous posts. Be sure you have a clean source of fuel and a good fuel filter. A full ignition tune up should be accomplished before tackling carb work.
I also recommend the use of 'alcohol free' gasoline whenever possible. Good Luck.

thanks for all the advice so far. I knew the carb was a replacement, I am working on and trouble shooting the vacc problems. I guess I might need to save save/plan on replacement

NADZ

500 cfm is way too big for a 304. The larger the venturi the weaker the signal to the carb the less accurate the metering will be. With a lot of work, you might get it to run ok, but you would be far better off finding a carb better matched to the engine. A 304 will never flow 500 CFM at speeds where it will stay together.
Unless you are very experianced with carbs, and understand how to change/adjust the balance between the idle and main metering circiuts, it will always have bog off idle. The engine will not transision between idle and main smoothly because the carb is too big for the engine requirements.
Look at the Ford 300 six, it is about the same displacement and runs a 1bbl when carb'd. Even the heavy loaded IHC 308 runs a small 2bbl. The OEM spent time to get the right carb, I'd look for one of those or sell the 500 and look for something in the low 300's or even less. More isn't better.

I'm going to stir this up a little and suggest a Chevy TBI conversion.
They are rock-solid and as close to "anvil simple" as you can get in fuel injection.
Binder Planet has some threads.
Basically, TBI is a two-injector "overhead sprinkler system" that takes the place of your carburetor.
The TBI I'm talking about would come off 1988 to about 1993 Chevy and GMC trucks and vans of the 5.7, 5.0 and 4.3l V-6 dispacements.
If the donor vehicle has a TV (throttle valve) cable in the auto trans--you're probably right.
Hurdles---
1) Base adaptor---Heck, I've made them out 3/16" plate...
2) oxygen sensor bung must be welded in exhaust close to the engine. You gotta run one. No ex leaks allowed in front of or at sensor.
3) fuel pressure is low but must be steady--spec is 10 to 13 psi. That's low for fuel injection. An in-tank pump will most likely be needed. That's what I would try to do. Many European and some Fords ran external FI fuel pumps so that IS possible.
4) ECM, wiring, sensors.. ECM is usually mounted near glovebox but an area outside of engine heat and weather inside the cab should be fine...get everything from one donor-computer, wires, sensors, air cleaner.
5) TBI is a "speed density" fuel injection. Therefore MAP "density" (Manifold Absolute Pressure) and engine RPM "speed" are the two main inputs. Obviously coolant temp, oxygen sensor inputs are important, too.
6) which brings us to 6. TBI requires a GM HEI-style distributor to run. Basically you would need a IHC 304 bottom on the dist with a GM HEI top.
There is nothing special about HEI electronically. It uses the same kind of magnetic pickup assembly to sense what the engine position is that MANY other makes did. What's different is the GM HEI ignition module and how it "hands off" timing control to the ECM above a low-threshold RPM (like 300 RPM).
I'm going to try TBI on my projects.