I am the 2nd owner of this low mileage rig, had the trans electronics replaced but still am having rather lackluster performance and some strange behavior.

Specs
318ci Magnum V8
4sp auto
club cab
1500 1/2 ton

Anyway I have a scanguage set for fuel rate & MPG
when I accelerate and just stomp on it the truck takes off but not with much OOmf and the scanguage MPG reading is under 2mpg the hole way, if I PUMP THE ACCELERATOR 2x then stomp on it the truck takes off much stronger and the MPG meter usually reads 3-5mpg

Why do I have to pump the acclerator to take off decently?

What might be causing my truck to accelerate slower than my 1982 NA diesel suburban?

Also something else I have noticed is that the truck misses quite heavily after sitting during rain for extended periods and takes a fairly long time to stop missing, odd part is I get better mileage
when that occurs. On one long trip it missed for 30miles but I got over 18.5mpg which has never happened again.

Any ideas what I should be checking or replacing?

I also have a squeek coming off the fanbelt again, I just replaced the water pump at 48k miles and am up to 56,000miles.

My mileage on the highway is rarely above 14.5mpg, anything I might do to improve that? I am finding that using the pump the accelerator trick has moved my in town MPG's up about 2 mpg but obviously no effect on the highway.

Thank You
Ryan

 

distributor cap, plug wires


as for the squeak, try moving the pulleys in and out and see if theres any excessive play

 

I had the EXACT same problem. In the end I figured that water was coming in past the large rubber seal below the windshield, then somehow dropping down into ONE of my spark plugs. Ever since I replaced the plugs, wires and distributor and re-sealed that seal it has been running fine.

 

i have this problem with my truck, but its only off road, i hit ny kind of water. my truck will quit, but i could just be in a pudle and she quits... ones i am out of the water. im good, its wierd, but i am going to be replacing the plugs wires, coil, distributer cap and sealing that cap with some silicone, and coil aswell... hopefully it will stop

 

Replace cap and rotor and run a dab of dielectric grease on the bottom of the cap and every electrical connection on the coil, disty cap and spark plugs. Moisture under the disty cap is a common reason for rainy day bogging, usually due to a crack in the cap but can also be due to a bad seal, hence the dielectric grease around the rim of the cap.

 

Thanx guys, plugs are probably on order along with the cables and the rest, that might take care some of the acceleration issues as well if the plugs are fouled and the cables worn.

As for the mileage I am slowly working my way up using a scanguage, its amazing how much effect driving differently has on MPG with these rigs, a little coasting goes a long way.

Cheers
Ryan

 

Your talking about that seal above the engine on the plastic vent peice? (the rear hood seal)

Ive noticed in quite a few pics that these trucks have those seals. But my truck doesnt. Im guessing somone took mine off before i got the truck. Should i go to the parts store and get a roll of that universal door/trunk weatherstrip and put some there? Im alittle worried about water leaking down onto stuff..Both in the rain and when i wash the truck.

 

Maybe someone else on the forum can verify that it is standard on your model before you go get one. I would bet that the part is expensive, so go grab one from a scrapyard if you can. The reason they suck is that the plastic sticks out a little directly above the distributor. The rubber strip also loses its stickiness after a while. Combine these two and the strip does not seal out water directly above the distributor.

 

It's really easy to loose those seals if you do some work on the truck and don't put them back. I also wonder how many people are missing the two foam seals at the L & R edges of the hood. I have had to glue mine in place twice and they still vibrate out of place. Seems like the hood and these beasts tends to vibrate a lot (or maybe it's the way I drive) but mine do keep moving. If I were careless they would have slipped off and away on the road. but I get them before they get too loose.

 

im missing the right side one
a good fix would prolly be some thick door seal foam, for like sliding glass doors