Power

[jimrs]

I have a '86 KC 4x4 with the Z24i TBI that is new to me. It's all stock except it is lifted 3" and I have 32x11.5 inch tires on it. I got it running good, new plugs, wires, cap, valves adjusted etc. I live in the mountains and typically drive from 3-9000 feet and have the timing set at 10 BTDC. I'm in CA and the sticker on the truck says I should set the timing at 5 BTDC. BTW it SMOG tested really clean. My issue is power up hills. A hill of any steepness and length and I end up in 3rd gear running 45-50 MPH at 3000 RPMs tops. In 4th gear when I floor it I hear an increase in air being pulled in the carb but no more power. I'm wondering if I can advance the timing any more without hurting the engine or if it will give me anymore power. Of course I don't want ping. Maybe I just have to accept a 27 year old 2.4L engine with 177K miles on it is doing the best it can. I'd like to know what some of your experiences are with timing and power. Thanks Jim.

[PEZi]

The power on this engine is a bit weak. It has decent low end torque, but the power for higher end stuff is just not there. The Z24i with TBI is a bit better than the carbed version, but aftermarket carb options will still work out better than what you're currently working with. The biggest issue, however, is actually your wheels. I know lifting it and having big tires looks cool, but it is a lot more weight, and specifically rotational mass that is near impossible for that little engine to spin with efficiency. That makes hills terrible. Best options are at a minimum getting a new carb for the thing, or swapping to the ka24

[jimrs]

Thanks for the reply Pezi. I know pushing the big tires is a issue. The fact is I would not have lifted this truck and put on big tires myself. But I bought it that way because it was in such good condition for it's age. I am considering lowering it some and going back to a more reasonable tire size like 15x30x9.5 inch or maybe smaller. I use it for back roads but not off road and of course it spends most of it's time on the highways. Being in California I don't think a carb swap is in the cards and engine swap definitely not. Your right though, it sure looks cool.