Engine Misfires And More Misfires. Carb Guys Get In Here!
- Thread starter 89'notchback
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the problem isnt going to be in the distributor, but rather somewhere before the distributor.
Like where? I've jumped the distributor straight to the battery before with no change
Since you do not like electrical answers, how much play do you have when you twist the rotor, not accounting for the spring and vac advance? If the gear on the cam is worn or the timing chain is loose, the timing can fluctuate and cause problems. That can be also checked with a timing light and 90 degree marks on the Harmonic balancer.
well then it sounds like you have taken care of everything. you have fuel, you have spark on time, and you have no vacuum leaks, so unless you havent run a compression check, and you are sure that your valves are sealing properly, then you missed something somewhere if you still have a miss.
I did a compression test when it first started missing and it was fine. I'll try it again when I get some time over the weekend. I have a friend that helps me and he's worked on cars for 30+ years. He has no clue on what it could be either. And we have done pretty much everything and that's why I don't know what else to do.
Since when do I not like electrical answers? I'm at the point where it HAS to be electrical. its just very frustration since I've had the problem for over 1 year and can't get anywhere with it. I'm replacing the solenoid like you said. I've already checked continuity. Yesterday I replaced the entire ignition with (and I'm sure I'll get crap over this) duraspark distributor/ 4-pin HEI module/ and tfi coil. Got it running and it has still got a misfire. I'm doing everything I can
Also, this must be a fairly new timing chain cause it's very tight. It's not loose at all.
Here's some videos I took awhile back.
Here's my vacuum guage reading.
View: https://www.youtube.com/watch?v=y1UVNx2n9xM
Use headphones on the one you can hear the "bump" noise.
View: https://www.youtube.com/watch?v=pXS9jMwA21A
Here's my vacuum guage reading.
View: https://www.youtube.com/watch?v=y1UVNx2n9xM
Use headphones on the one you can hear the "bump" noise.
View: https://www.youtube.com/watch?v=pXS9jMwA21A
At this point it's gotta either be gas or timing related. But I've got a new fuel pump, filters, and carb. So that leaves timing. If timing chain seems tight could it somehow jump a tooth? And cause a miss like I have? If it's a possibility I'm gonna tear the front cover off and take a look. Is there any way to check without taking the cover off?
your compression numbers look good, 15lbs from high to low is good.
it is possible that your chain is loose.
Okay. The chain and cam is the only things I have not replaced and the cam is a newer crane cam. I'm going to open the front cover up and see what it looks like and replace the chain. I'll report back when I have the time to open it up. Thanks for your help!
Are you sure the carb is adjusted right? ..in the vid when you rev the engine i can hear it suck in air..like a vacuum leak or a carb that's not getting the right amount of gas when you rev it. It does not sound like ignition missfire it sounds like fuel to me.
- Mar 2, 2015
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I was reading the post and that tapped hole in the back of the block looks like the hole for a knock sensor....are you sure the block and cam run on the ho firing order. Just asking because I bought a mustang once that ran like poop....it had a regular 5.0 motor and the plug wires run for the HO. Swapped wires and it ran like a truck.lol
Lol yes I'm sure. I've rotated the engine by hand with the valve covers off just to make sure. It's definitely the HO order!
madmustanger
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- Jun 1, 2015
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Madmustanger here: For what it might be worth i had a local guy do changes from the stock items to performance items as follows worn out carter afb carb to elderbrock 1406 stock coil to msd streetfire coil the msd is based on ome just puts out 20,000 more volts than stock ford coil msd plug wires heavy-duty duralast distributor from 2 into 1 exhaust to true duels with cherrybomb glasspacks ran good for about two days had noticed a surging problem.
So on a Sunday morning went to check for vacuum leaks noticed coil boot wasn't on coil nipple so pushed it where it should be traced wires to distributor to check that connection and don't know if i moved distributor top but found out later rotor had damaged the cap leads causing it to misfire blow back thru carb wouldn't crank at all.
So had musty towed to mech my buddy used they found the chewed ends in cap replaced cap,rotor,put in new plugs,adjusted timing and tweeked carb so musty runs like bat outa hell if any of this helps great if not sorry. PS Might check for extra inline fuel filters most of fords I've owned had extra along the undercarriage gd lk
So on a Sunday morning went to check for vacuum leaks noticed coil boot wasn't on coil nipple so pushed it where it should be traced wires to distributor to check that connection and don't know if i moved distributor top but found out later rotor had damaged the cap leads causing it to misfire blow back thru carb wouldn't crank at all.
So had musty towed to mech my buddy used they found the chewed ends in cap replaced cap,rotor,put in new plugs,adjusted timing and tweeked carb so musty runs like bat outa hell if any of this helps great if not sorry. PS Might check for extra inline fuel filters most of fords I've owned had extra along the undercarriage gd lk
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