Hi all. Was referred to your forum by the guy at the counter of an autoparts store. I have an 89 motorhome with a 460 motor with California Emissions pumps—I don't live in California. Any of you familiar with big motorhomes knows that they weigh tons, are slugish and burn too much of Arab gas.

I'm told that the smog stuff virtually strangles the motor and robs 30 HP or more—bottom line: I'd like to get all the smog stuff off the engine to make it breathe easier, get the HP back and maybe see a couple more mpg.

You all probably know, it has a Holley carb and, it is my understanding, the smog system is designed to make the motor run hot (it doesn't need help), that also controls the distributor spark advance (mechanically?).

Some items of concern: when at a stop sign raw gas fumes seep out from under the doghouse, it wants to choke-out when accelerating away from a stop (unless you mash the pedal most of the way down), has an occasional but slight backfire (with the raw fumes could pose a fire hazard), requires starter fluid from a cold start or you'll run the battery down, and perhaps last... the dash A/C only delivers cold air when I am decelerating (?) under acceleration or a steady throttle is won't blow or it just trickles cool air.

Other than that it is one hard starting son-of-a-gun (except when warm).

I talked to a Ford service tech about it (one who knows Ford/Holley carbs) who said he'd really like to help but can't because of regulations and said as an employee, he can't even refer me to a shop; plus, I wouldn't want him to do anything that would jeopardize his job security.

So, that's how/why the parts guy pointed me your direction. Question #1: How does one remove all that stuff or where can I find information to do it?#2: What carburetor and ignition can or should I refit on it.

I'm sure most all 1989± 460s were basically the same, with either Fed and/or California air pumps: one Fed (Nippon) and one California. They are on a shared belt driven off the front pulley of the alternator if I remember right.

Obviously, isn't a truck, although it kinda drives like one, it's only because of deadends and suggestion of the autoparts guy that I've found my way here—if any one of you can lend expert assistance/information/how-to I would truly appreciate it and sincerely thank you in advance.

Alan

 

Welcome to FTE-
The first part is that there are electronic controls on the carburetor that tell the computer where to set the timing at, and also let the computer control the fuel mixture. Vans are pretty hard on electronics, just because of the small engine compartment size and high heat in that area. If any of this stuff is damaged, the computer goes into fail-safe mode, where it runs the engine rich and sets the timing at baseline, usually around 8*.
To replace the carb and ignition, for pure ease of installation, use a distributor from performance distributors. They are a little pricey, but well worth it. It's only one wire to hook up, and they make a really hot spark. For a carburetor, you can go with a Holley, which you really have to spend some time dialing it in properly, or an Edelbrock which comes pretty well calibrated.
Your transmission should be a three-speed c6, so there shouldn't be any concerns about it shifting properly.

 

Hi Jared. Thanks for the info, I'm glad to find an experienced source on this stuff, as I haven't found many Ford knowledgeable folks; seems like lots of 454's in motorhomes for some reason. I appreciate it.

Is this a pretty straight forward swap-out? Intake manifold should be fine, assuming the carb includes an adapter plate? I've seen reference to using an Edelbrock 1903 or 1906— they appear to have a lot of tube connectors on them; is this the correct model or is there another recommendation? Electric choke, yes? Do the throttle linkages fit or require an adapter kit?

I'll check-out Performance Distributor. Based on your remark, would this be an electronic ignition ("just one wire to hook-up")? Any thoughts on plug wires? Is arcing a problem on these motors with hotter ignition? I've read a lot of posts referencing backfiring, anything there to be concerned with? Is this a winter project or would it be best done while in warmer temps?

With regard to the air pumps (smog) can a guy just disconnect all the hoses and remove just the belt from the alternator pulley that turns them OR take out the pumps too to open up that space? I don't think anything else shares that belt, and the alternator tensions it; but I suppose I'd better check that out closely. Are there any ports to plug on the manifold or elsewhere?

About vac hoses— are there any (or many) that will be left un-used by a replacement carb/ignition set-up that will need to be capped?

You are exactly right about the tranny, it is a C6. And that's something that never crossed my mind, thanks for the heads-up. I appreciate your input.

Thanks again.

Alan

 

Sounds like your accelerator pump in the carb is most of your problems. Probably not squirting anymore and possibly leaking onto the engine. I would throw a rebuild kit into the carb and see what happens before I spent a bunch of money converting stuff over.

 

Would your RV be a Coachman by any chance

 

It's a 37' Airstream on a Gillig bus chassis with a 460/Holley/C6. I don't know much about other makes of coaches except there are a lot of really nice looking rigs on the road and a lot of really nice folks traveling in them.