[Ramchargin88]

Drove my RC today and noticed it really lacked part-throttle power and required a lot of downshifting to 2nd to accelerate from 35 to 50.

Some background: truck was pretty much parked in late August 02 when I got my new Ram. Filled the tank with fresh gas about 6 months later. Drove the truck for a week around August 03, parked it again with partial tank of gas. Replaced the distributor, cap, rotor, and plugs a couple months ago at which time I ran 1/3 can of SeaFoam thru the TB and poured the other 2/3 in the tank that had about 1/4 full of gas (34 gal tank). Noticed truck still missing/backfiring, lots of loud ticking from injectors and poor spray cone.

This afternoon I replaced both injectors and the inline fuel filter. I drained the line from the filter to the TB. Drove it and put $10 of fresh gas in it to thin down the SeaFoam a bit (was just under 6 gal...geez).

Truck seemed slow taking off from a stop, requiring me to nearly floor it to accelerate at a rate on par with traffic. When I did floor it from a stop it seemed to take at least 10-12 seconds 0-60 and just three years ago I know it was less than 9 seconds 0-60.

Only once while I was out today did it backfire, and I had been doing 30, floored it causing a downshift to 2nd <backfire> then resumed accelerating.

Any thoughts on what might be causing this? IIRC, after I replaced the distributor I set the timing about 12 BTDC. I read the post about the stuck EGR and wondered if that might be contributing. Another thing, I removed the belt from my AIR pump years ago and never removed or plugged any of the other parts of the system, just slipped the belt off. Any thoughts would be appreciated.

 

[Smokey]

Typically, a backfire like that is due to:
Hot glowing crud in a cylinder that ignities the new mixture coming in before the valve is closed;
Which can be resolved by some high rpm running, or the intentional slow dribble of water into the throttle body.while holding it at fast idle.
OR
An instantaneous leam condition caused by opening the throttle, which is not adequately compensated by the enrichment circuit.

Since yours has been sitting and seldom run, I'd try the crud removing "cure" first.

Unfortunately, it could be as bad as a slack timing chain...

 

[Wile E Coyote]

Pull a plug and I think you'll find light or white fluffy deposits, clean em off and you should be GTG. Why? That Sea foam or any other additive at high concentration will cause the plugs to fluff. ( Or so I am told)

 

[Ramchargin88]

Thanks, I'll try the plugs in a bit after the engine cools off. I just pulled in from about a 90mph jaunt on the freeway up a couple hills at WOT to do the "Italian tune-up" method. Also checked timing at idle fully warm, and with the coolant temp sender wire disconnected it looked more like 13-14 BTDC so I'm going to try retarding it to factory spec of 10 to see if that helps low-end.

I am afraid a slack timing chain is contributing somewhat since I have 147k miles and it has not been replaced since I got the truck at 66k. Its doubtful a chain would have required replacement prior to 66k, so it may be the original.

To complicate the situation, on my way out to lunch the truck stalled on me. I was sitting at a light nose slightly uphill (about 3-4 % grade max) waiting to turn right. I gassed it to start going and pulled maybe 2 trucklengths and it stalled. Took about 20 seconds cranking to refire which seemed like forever with the f*@$(ng gray-hair in the Continental behind me blaring their horn like I could do anything about it. I thought it may have been trash getting caught on the in-tank sock filter, but then I remembered typically when I accelerate and fuel flows to the back of the tank it goes AWAY from the pickup/sender since I can watch the needle drop then come back up under braking. Nose uphill should push it away from the pickup more. This was with about 3/8 tank showing on the needle, so I don't think I was low enough to starve the pickup.