- City
- Rock Hill
- State
- SC
Hey guys, It has been a while since my last post but a lot has been going on. Besides the family growing and kids getting older and more active, my Jeep project has also continued on.
Two years ago(?!?!?) when I came up to the Sand Blast event, a few of you pointed out that my ride was smoking and you were not wrong! In fact, I had F'ed the timing up something fierce and just hadn't realized it yet. So, I've been working on that and have some questions.
Here is the situation again: Gen 1 SBC stroked to a 383. Vortec heads. Holley 750 carb (yes, I know it's too big, but it is what I have at the moment), MSD Street Fire HEI.
Timing is currently set to 32 degrees advance.
My issue is that I have a misfire. I say this because all of my spark plugs look fabulous except for #8, which is fuel fowled.
Here is what I've done to try to diagnose the issue:
1) Checked spark with a spark tester - PASS. All cylinders check with spark at a pretty good gap; far greater than a spark plug could be gapped.
2) Pulled the valve cover and all "looks" normal, and no excessive lash in the rockers. I have not pulled the head though.
3) With the engine running, I pulled the #8 wire from the distributor and the engine didn't miss a beat. I put it back and pulled #6 and the engine chugged. I put it back and pulled #3 and the engine chugged. I put it back and pulled #8 again and the engine didn't miss a beat.
4) With the spark plug tester, I tested at the distributor - #8 has spark.
5) I swapped the #6 and #8 wires and did the "pull" test and the same results. #8, with the #6 wire, when pulled, the engine didn't miss a beat. I put it back on, pulled the #6 wire and the engine chugged.
6) I had put on a new distributor cap last summer as I have been fighting this issue for years. I pulled the cap to inspect it and found no weirdness. The spark is hitting in the center of all 8 of the pickups in the cap and there doesn't appear to be a difference between any of the pickups impact points, even on #8.
7) While I had the cap off, I cleaned off the pickups with some light filing and when I put it back on and started it up, it ran really smooth for about a minute even after a rev or two. Then, it was back to its tricks of being a little rough, a little spitty and a tiny bit of back talk from the tailpipe when coming down off of a throttle goose.
8) I forgot to also say that I did a compression test of all cylinders and they all shows 180 PSI and held there. I didn't hold it for a long time, just a few minutes each cylinder, but they didn't seem to leak, even #8.
So, I'm stumped.
I'm of two minds and would like your opinion:
Option 1: Swap in a new MSD Billet and 6A control box and see if that fixes it. - this is the $900 option
Option 2: Pull the head and see what is going on with the valves such as something sticking the intake valve open a bit letting stuff through that is fowling the plug. (this is a wild ass guess...I have no idea if that is even realistic)
Option 3: Take it to a shop and let a mechanic tinker with it.
Anyone have any idea what the heck I should do next? Thanks in advance!
Two years ago(?!?!?) when I came up to the Sand Blast event, a few of you pointed out that my ride was smoking and you were not wrong! In fact, I had F'ed the timing up something fierce and just hadn't realized it yet. So, I've been working on that and have some questions.
Here is the situation again: Gen 1 SBC stroked to a 383. Vortec heads. Holley 750 carb (yes, I know it's too big, but it is what I have at the moment), MSD Street Fire HEI.
Timing is currently set to 32 degrees advance.
My issue is that I have a misfire. I say this because all of my spark plugs look fabulous except for #8, which is fuel fowled.
Here is what I've done to try to diagnose the issue:
1) Checked spark with a spark tester - PASS. All cylinders check with spark at a pretty good gap; far greater than a spark plug could be gapped.
2) Pulled the valve cover and all "looks" normal, and no excessive lash in the rockers. I have not pulled the head though.
3) With the engine running, I pulled the #8 wire from the distributor and the engine didn't miss a beat. I put it back and pulled #6 and the engine chugged. I put it back and pulled #3 and the engine chugged. I put it back and pulled #8 again and the engine didn't miss a beat.
4) With the spark plug tester, I tested at the distributor - #8 has spark.
5) I swapped the #6 and #8 wires and did the "pull" test and the same results. #8, with the #6 wire, when pulled, the engine didn't miss a beat. I put it back on, pulled the #6 wire and the engine chugged.
6) I had put on a new distributor cap last summer as I have been fighting this issue for years. I pulled the cap to inspect it and found no weirdness. The spark is hitting in the center of all 8 of the pickups in the cap and there doesn't appear to be a difference between any of the pickups impact points, even on #8.
7) While I had the cap off, I cleaned off the pickups with some light filing and when I put it back on and started it up, it ran really smooth for about a minute even after a rev or two. Then, it was back to its tricks of being a little rough, a little spitty and a tiny bit of back talk from the tailpipe when coming down off of a throttle goose.
8) I forgot to also say that I did a compression test of all cylinders and they all shows 180 PSI and held there. I didn't hold it for a long time, just a few minutes each cylinder, but they didn't seem to leak, even #8.
So, I'm stumped.
I'm of two minds and would like your opinion:
Option 1: Swap in a new MSD Billet and 6A control box and see if that fixes it. - this is the $900 option
Option 2: Pull the head and see what is going on with the valves such as something sticking the intake valve open a bit letting stuff through that is fowling the plug. (this is a wild ass guess...I have no idea if that is even realistic)
Option 3: Take it to a shop and let a mechanic tinker with it.
Anyone have any idea what the heck I should do next? Thanks in advance!
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