Simple things- I'm an idiot

[mountainexplorer]

I bought a truck with a 454 in it. The guy said timing was off. I have had it sitting in the driveway for a month now. I moved the timing a bit, adjusted the carb, but it kept having this intermittant miss and backfire.

Tonight I was just going to pull it out with plans to re-cam it and check things out. Then as I started disconnecting the battery, it dawned on me I didn't check the plug wires for firing order.

1-8-4-3-6-7... wait... 7? That one should go to 5. So I switch the plug wires and now the backfire is gone. The guy who put the wires on wasn't too smart... but I'm not too much smarter for overlooking that the past month.

 

[ryoken]

cheap fix.

i can't tell ya how many times i've been hired to fix boats where the owners did tune ups and something wasn't right and that was the prob.. that and broken spark plugs...

 

[tRustyK5]

I had the same prob with a set of Accel wires once. One was sorta bad. Fine at idle but it'd miss under load. They were 'new' though so i had crossed them off my list of possible problem causers.

I installed new plugs, new iggy module, ungunked the mechanical advance, fine tuned the carb, twiddled with the timing all to no avail. It wasn't until my alternator ate the battery that I found the problem. The battery acid ate a few wires...so i replaced them thinking it was such a waste. Miss under load went away...

With all the stuff i had worked over it ran like a dream once the new wires went on.

rene

 

[ryoken]

yeah, honestly, i never realized how finnacky wires can be until i started working on boats...

if i get a rough running motor, its the first thing i do now, start wiggling them suckers...

 

[mountainexplorer]

This thing had a brand new expensive set of plug wires. I switched 5 and 7 to where they should be and drove it around the block. After setting off someone's car alarm (it's been open headers only since I bought it) I discovered it still was running crappy and there was still a bad miss from the passenger bank. So before the neighbors called the cops on me I pulled it back in and started yanking the motor out.

I found #8 spark plug was loose and the electrode pushed in so it wasn't making much of a spark. I also knew one motor mount bolt was already missing... but whoever put the new tranny in decided that 3 bolts was enough out of 6 holding the tranny to the block. I guess 3 of the top ones were too hard to get to so the easiest solution was to not put them in.

Plus the fuel line to the carb didn't have a clamp tightened down and the lower hose to the water pump didn't even have a clamp at all.

This is the same truck the guy paid his mechanic to buy and install a 205 T-case into, and put a new Comp cam in less than "10 miles ago"; and it still has a fulltime 203 and I can tell the intake and timing cover haven't been off in years.

 

[OffRoad]

wow, i sure wouldn't be going back to that mechanic.

good job on the plug wires allan.

 

[Chevy305]

Yeah, I accidentally installed the wires wrong once. Switch the 1 and 8, 2 and 7, 3 and 6, and the 4 and 5. Yeah it gave me huge back fires through the carb. So I switch to plug wires that have each cylinder labeled on the wire so this won't happen again. Check it