Hey everyone. I belong to a Vol. Fire Dept with a 1981 Ford cab-over pumper. It has a 534 with an auto trans. Holley 1150 cfm. Enroute to scene this thing cant get out of its own way. (Hope my house doesnt catch fire!) Takes damn near 1 mile to get to 55 mph. Granted this thing is carrying 1000 gal of water but it just doesnt seem to have any get up and go. We have had the thing pumping at capacity and notice the exhaust manifolds, Y-pipe and first 2 chambers of the muffler glowing cherry red. The big red truck isnt supposed to be red underneath too! We've melted asphalt with it along with torching yards. (Embarressing!) My question is: Isnt this alittle large of a carb? and the glow in the dark exhaust...is that normal on this engine running damn near wide open??? Hate to think that the fire truck is a fire hazard! Thanks guys!

 

Thats Sounds like a heck of a note. I used to be at a vol. fire dept with my uncle and they had a 534 also and i don't recall it ever getting hot. it had the original carb though. well of course he worked on the trucks so they were in pretty good condition. sounds odd to me. how high is it reving? How often is it to the floor (ie. all the time, 50% 75%)? try letting up a bit on the throtle, nothing to slow you down but enough so were it won't rev out as high. not an expert but try it when you aren't on a call. take it out if possible and expiriment with it. find it's sweet spot.

1978 F-250 Ranger Explorer 4x4
351M, C6, Np205, D44 Front, D60 Rear 4.10LS

 

That's Deffinately NOT NORMAL!!!!

1978 F-250 Ranger Explorer 4x4
351M, C6, Np205, D44 Front, D60 Rear 4.10LS

 

Morning guys. I have found that when trying to get down the road when the old girl is cold, if you let up just enough to back out of the secondaries it'll pich up about 3 or 4 mph. While pumping and glowing red hot, engine rpm is under 3000 rpm. The carb is original, I was told it was 1150 cfm but i guess I should verify this myself. My bad for taking somebody's word for gospel. At our Dept, unless its broke it aint worked on. I dont know the last time the timing or anything was checked on it (if ever). Keep ideas coming please so I can pick a good place to start! Thanks!

 

let me ask some people and try and get some answers for you. Be back later tonight or tomorrow morning.


1978 F-250 Ranger Explorer 4x4
351M, C6, Np205, D44 Front(not 100% sure, have issues), D60 Rear 4.10LS

Drive It Like You Stole It!!!!!!!

 

Hey guys. Just got back from the fire dept and i have some numbers off the carb. It's a holley with vac secondaries...but with a Motocraft tag on it. The numbers are...D9HE EA C 9K9. I'm researching it now but without much luck. As for engine rpm...governed speed is 3200 rpm...Max capacity of the pump is at 2600 rpm. So when we're pumping with the glow in the dark manifolds we should only be turning 2600 rpm. Any ideas let me know! Thanks!

 

Sounds to me like you need to do a tune-up, new plugs, wires, cap, rotor, double check the points and condensor (or change to an electronic setup). The glow is not normal but retarded timing could cause it, and if the plugs are worn it will change the timing. It's the little things that keep stuff going, as a fire dept you can't afford downtime on any equipment, my advice is to keep the maintenance up on ALL the vehilce in the dept. You wouldn't like it if your house burnt down because the dept was (no offense) too cheap to maintain the vehicles, plugs, wire, cap, rotor, oil filter, oil, and air filter for the truck should be under $50 total. So I cannot stress enough that you need to at least do that much...... You might also check to make sure the choke is working properly, as a lean condition can make it run hot as well, and cause serious damage to the engine.

 

Another poster advised you to give this old girl a tuneup and that is
probably good advise if it needs it. I would have thought a firetruck gets
periodic tuneups, but maybe not. The carb is not necessarily too big, as the
engine (especially this size) will only draw in as much as much as it needs.
The red exhaust makes me suspicious of the exhaust itself,especially since it
takes so long to get up to speed. Has anybody checked for plugged exhaust? Throw a vacuum gauge on it and make sure that it is free flowing.
Sometimes a vehicle that sits for extended periods of time (like a firetruck)
can get a mouse nest or a packrat building in the exhaust pipe......

 

Sorry guys. Maybe i wasnt clear or i was in a bad mood when i type my prevoious messages. The oil, filter and air cleaner are changed every january. Being a 1981 the truck doesnt have points..Electronic. And as for a tune up, i realize moisture has an effect on some components, but with only 11000 miles on a 23 yr old truck, how often do you really need to change plugs? Every year? 5 years? See my point? With the truck only have this many miles i wouldnt suspect the timing being off unless there was a timing chain issue. (Never heard of plugs changing timing..only point wear and chain wear.) The truck is started and run around the block a coupkle of times every Monday so im sure if somebody took up residence, their cooked by now. I'm sorry if im sounding like a smart *** tonite...****ty day. Dont take anything i say personal, Please. But in my community, we have 3000 residence. Doesnt generate a hell of a tax base. Our news truck is a tractor trailer with a 5000 gallon tank...1991...purchased used. our oldest is a 1968 Dodge front mount pumper with a 361 v-8 that will start before you can think about letting go of the key. I guess what im getting at is the remark i made about if it aint broke we dont work on it. We dont have money to throw around like some larger communities. If the truck starts, stops and pumps water reliable, we have a hard time justifying changing parts with only 1000 miles or so on them.(except oil, filters ect...) Well after 23 yrs of reliable service of starting everytime and pumping millions of gallons of water (by the light of the exhaust manifolds :-))The old girl is acting up. I pulled records today, (those dont cost much to keep) Last tune up was in Jan 2003. 850 miles ago. The transfer case for the pump comes off the back of the trans so it still racks up miles even when pumping. My gut feeling is that it is dumping fuel from the Holley. Im sure its backfired sometime in its life and i dont know if they had blow-out proof power valves in '81. The truck is loaded with emission controls which mean it has one of the not one but two air pumps on it. i think all the extra fuel might be burnt in thwe manifolds right after the air injection. Once again let me stress...****TY day. I hope i didnt **** anyone off. didnt mean too...but if its any consolation...i feel better from venting. thanks guys for being there and giving me your input. Chris

 

These were common problems with the 534's at the end of their manufacturing run. It is good advice to check for restricted exhaust, tune up, ect., but you also should look at the air pump system if it has one. Too much air into the exhaust will cause the manifolds to glow. Another thing to look at would be the carburetor. I doubt that it's an 1150, it sounds like you have the stock one on there, which I think is around 600 cfm. If the power valve is blown, it could cause lack of power, and over fueling (which also could cause the exhaust to be too hot if the truck has an air pump). Most C series trucks had an intake fresh air/heated air system, check and make sure the engine isn't getting hot air all the time.

 

It sounds like retarded timing to me. I dont know how it could have possibly got this way, but I'd check it just to make sure. Timing lights aren't that expensive.

I'm not exactly sure if those had vacuum advance, but if it does, unplug it at idle from the distributor, plug it with a golf tee or something, and set the timing at 10 degrees BTDC. Plug the vacuum advance hose back in and try it. I have a feeling this may solve some of your problems.

 

thanks guys. I'll be checking these things this weekend. my appoligies to the moderator. i didnt realize you edited profanity. Didnt mean to cause you extra work. But while youre at it can you correct my spelling too?

 

Care to clue us in and tell us what the problem was? It has been posted
that this truck gets good maintenance, so maybe you could tell us what
the problem actually was. Thanks.

 

Sounds like possibly a muffler baffle came loose, also check the distrbutor drive
gear as sometimes the roll pin shears and lets the timeing become retarded, also
check fuel pressure @ volume , it may be running lean under load [ ie ] leave out of throttle @ it picks up speed .
I HOPE THIS HELPS!!!! HOTWRENCH

 

Kristoph30, the carb is worth looking into. I had a nearly identical experience with a company tuck. I don't know what the motor was, or what emission equipment it had. Ryder did fleet maintenance and repair.

I do remember the feeling in my gut when I saw the head pipes and muffler going "plastic" from the heat.

The mechanic who returned the truck said the carb was dumping so much fuel that it was burning in the exhaust.

One thing to keep in mind with a vehicle that has been idle, or sees limited service, is that gaskets will age and deteriorate regardless of mileage. That spin around the block is one of the best things you can do, provided it reaches operating temp..

Good luck, Mike