Definitely tune it up, change hoses, belts to get a base line on maintenance and prevent future problems. If something goes it will be on a trip and has a way of being a lot bigger problem than just a break down on the way to the store.
At 45 mph and 2400 rpm I take it you were in drive. Get used to down shifting even though it is an automatic. Under those conditions the torque converter on the trans is slipping a lot and creating a lot of heat that can break down the trans fluid. It won't all be dissipated from the cooler and some will end back up in the trans. You won't get up the hill any faster, that is the nature of a larger vehicle and steeper grades, but it will help your engine and trans last a lot longer.
CSpenceFLY wrote: If it is carburated make sure the 4 barrels are opening when you floor it. Mine stick sometimes and it runs like a VW bug....
I've seen older coaches where the throttle cable was so poorly adjusted, the secondaries never opened.
Gale Hawkins wrote: If electrically all of the parts are good and in working order TIMING settings can be HUGE in this generation of the 454.
Some guys have found that the timing curve for those years have some strange anomalies. They have re-chipped and found some extra power. Headers will also help a bunch, especially since most older 454s have manifold leaks.
GM had many a recall on cat converters in 1990-1992 on trucks and P chassis. If you are running a bit hot, lots of pinging even with timeing set correctly and a loss of power at wot...check the CAT!!!
Geneva & Warren
04 34m expedition
300 ISB cummins/6speed
Oak hills CA
Also check to see if you have a gate valve on the left bank of your exhaust. It's a valve that is closed when the engine is cold and it forces exhaust through some risers in the engine and out the right side exhaust. If it is not working correctly it will kill your engine power and you will run hot.
"You're lucky to be alive my friend."
Quote from the "Do it yourself police" and many others that have known me.
I have an '87 454. It is standard carb. and had original everything else when I got it. I had to replace the left side manifold last year and at the same time had all the rest of the exhaust piping and mufflers replaced - with 3" pipe (from 2") and Magnaflow mufflers.
Well, that gave it a considerable power boost, but also made it sound like a '70s muscle truck. Too loud! So, just recently, I had a set of 30" glass pack mufflers added ahead of the Magnaflows. That really did knock down the noise quite a bit and didn't effect the power. I also removed the dash AC condenser which opened up all the area in front of the engine's radiator - and it now runs much cooler.
I just purchased and received a set of Headman ceramic-coated headers and will be having those installed very soon - perhaps next week. I'll let you know what that does.
There is more power in the engine, but at what cost?? More heat, more stress on the rest of the drive train, and more gasoline (and certainly more money).
I down shift to second at 40 mph, and I don't worry about being able to race up a hill.
Brian K7ZRZ
Campgrounding hosting - Oregon State Parks
1987 30' Holiday Rambler Class A
GL1800 Goldwing - Honda Scooter Mounted
2000 Silver Miata LS Toad
Thanks for all the replies. BTW I have the TBI version. Based on what people have said, it sounds like the engine is just performing to it's capabilities. I think I will go with plugs/wire/cap/rotor because it's cheap and probably never been done. Then check the timing. What is the base timing for this engine and what have people changed it to with success?
As for the cat, the engine doesn't run hot (according to the idiot gauge), and I've had plugged cats before on other vehicles, and nothing leads me to think that may be a problem.
I use the Rotella 5w40 synth. in my 93 passat diesel, so maybe I will just switch to that in the MH for the next oil change. I run at least 12k miles on the passat between changes, I assume that may not be recomended for the MH? But, being that I only drive a couple k miles per year, I guess that would only be 1 oil change per year. The Rotella is NOT CHEAP in Canada, and hard to find. I usually buy it at wally world in the US for $16 gallon.
The other thing that needs doing is insulating the doghouse for sound and heat, I have checked the gasket, and reseated it, but the heat just bleeds through the carpet. What have others done?
Thanks again all!
Ian
1991 Winnebago Warrior 30eu
OLD RIG
2006 Chevy Uplander 3.5l
2005 Jayco Sport 165 18' 3500lbs loaded
Putnam WD w/800lb bars
Acar friction type sway control
Hoppy digital display brake control
BALANCED tires! (Please everyone, balance your tires!)
The other thing that needs doing is insulating the doghouse for sound and heat, I have checked the gasket, and reseated it, but the heat just bleeds through the carpet. What have others done?
Thanks again all!
Ian
Ian, I use 3M super glue spray and double sided fire proof insulation then "custom fit" the insulation (first) and lay it in the dawg house.....
After that I'll use the aluminum tape and go over the edges (where cut) and tape it down....Even along the edges where the house sits on the opening....
Now for your timing aspects......Look up SUM1 or me for a super long thread on timing issues.....That will wake up your engine cuz lets face it...The ignition system is the brains of the engine while the cam is the heart.....Good luck.
The base ignition timing for the 454 TBI is 4 deg. BTC. I'm on my 2nd MH with this engine. Bumping the timing to 6-8 BTC makes a noticeable improvement in performance. To check the timing, the tan/black stripe wire to the distributor needs to be unplugged. There should be a timing indicator below the pulley, use # 5 plug wire. I insulated the doghouse of my Sunflyer with Dynamat Extreme, a little pricey, but a huge improvement in reduction of heat and noise intrusion into the cab.
Don't forget you're towing too. Life is always easier without that 2-3K lbs on the back. I've done the headers, custom ignition & exhaust too, and they do help on the power. But then on the few times I drive it without the car on the back, it feels like I'm driving a hot rod by comparison.
Put the tow on the back and throw it up a good grade, she'll do alright, but as Scotty from Star Trek would say, "I'm givin' it all she's got Captain! But she just won't go any faster!"
Lumpman
1994 Georgie Boy Cruise Air
Chevy P-30, 454
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