A compression test may not be such a bad plan......

 

well my miss has seemed to have disappeared. i routed the coil wire per the tsb and it seemed to have solved it. i have some spark knock due to my 91 superchips tune because ive been running 87 the last few weeks due to cash flow.

 

ok, my mis is back. im getting p0300 with the light on, and p0305, and p0308 both of those are pending, according to my scanner. i cant seem to shake it.

i have an msd blaster coil, would installing that help at all, also is there anything special needed to install it?

my plenum is fixed, but im all of a sudden getting a cyl 8 mis again.

it happen just about everytime i get into the throttle for passing, or speeding up purposes. its getting old, and fast, because i cant pass the obd2 test for inspection due to the cel.

any helpful tips would be great!

would taylor 10.4mm wires be overkill? also gonna change out the temp sensor, and go with the autolite 3293's or whatever the number is, to see if it helps.

 

Pull the plugs, and see what they look like. If those look ok, do a compression test.... and see what the numbers say. (leakdown test if you can.)

Have you ran any seafoam thru the engine? Might have some valves carboned up, that aren't sealing completely. (may be cracked heads too...... sorry.)

10.4mm wires are indeed overkill. A more powerful coil might help...... verify the rest of the ignition system before replacing it though. (cap/rotor/wires/plugs) There is only two wires, and the coil to distributor wire to worry about. Dead easy to hook up.

What plugs ya got in there now??

 

just the stock champions that were the cheapest. would going one step colder help? i havent done seafoam in a while

i was thinking about replacing the heads with some from odessa soon anyways, that way i can do headers at the same time. i dont dare touch the manifold bolts the way it sits...... way way too rusted up.

only reason why i asked about the coil is because msd said i have to get some resistor, i found it on ebay and its not too expensive.

plugs wires cap and rotor are only like 6 months old at most. did them when i did the plenum.

 

I would check the plugs and such anyway....... I discovered that not all of my oil consumption was due to the blown plenum..... and I have a couple I need to pull every couple months, and clean off, to get rid of the misfire......

May also want to check quality of spark at each cylinder....... seems that one of the possible failure modes of the crank sensor is consistent weak spark on one or more cylinders...... the meaner coil may mask that for a while.....

I would do what MSD says about Coil installation...... don't wanna smoke the PCM.

 

also, i replaced my crank sensor back in 2010, but i went with the cheapest one napa had, it was a standard motors product, and it was 45 bucks. should i replace it again with a better unit? which do you reccommend?

 

I would check and see if it is indeed the problem before just blindly replacing it. SMP supposedly makes good stuff.... but, if it does indeed to be at least part of the problem, go with one from the dealer. Yeah, I know, hideously expensive.... but, much better quality part. (hopefully....)

 

so, i drove the truck a ton today... i got on it up to about 80ish, which tops out 2nd gear. around 4-4500 the cel starts blinking.

obviously its a misfire. thats the exact reason why i spent almost 4k on this 360 swap.

so what im wondering is... would broken clips on the injector connectors cause this? im at a loss. everything is new, except the coil, but i know its good.

any ideas?

 

Bad connections at the injectors will indeed give you a miss.