Need Help!! Or I'm pushing it off a Cliff!!! (1 Viewer)

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Joined
Mar 8, 2007
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5
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Location
Santa Rosa, Ca
I have a 1970 FJ40 with an 86 350 chevy. For some reason it keeps "jumping" or loosing time. It has an MSD Billet dizzy. I have replaced every part in/on the dizzy twice. I have also tried 3 different carbs (holley, edelbrock, rochester). I have replaced the timing chain twice and also tried a gear drive. I am all out of ideas I have no clue as to what it could still be. It will run perfect for a week or two sometimes only for a few minutes then it runs like crap. Either backfiring through the carb or the tailpipe. I get out adjust the dizzy either retard of advance so that it will run good again only for it to do it all over again at some point. At this point I'm about 99% positive that it is not mechanical.

I know what everything is on the cruiser except for two parts they are on this page here (Specter Off-Road-Land Cruiser Parts - Page 182-Switches, Relays & Flashers). One is called the "Inspection Plug" S.O.R. part #182-17A, the other is called the "U Computer EMS" S.O.R. part number 182-64A. Can someone tell me what these parts are? And whether they can have an effect on my timing issues.

Thank you to anyone with any information.
 
Put it all together with new OEM Chevrolet parts and a new carb of the model that originally came on it. The mish-mash of hop-up parts is likely your problem. Do a compression check first to make sure the long block is worth going forward with it.

The parts you mention certainly have no effect; a 12v socket and a 2f emissions computer.
 
You mentioned having the carb. If you also have a standard coil,
check to be sure the condensor is the correct one and is WELL grounded.

I have this set up in my 40' and this issue was intermittent... correcting it changed everything.
 
If all else fails you might want to suck it up, take the hit and check with a professional in the area. I know a great mechanic who did work on 350 a couple of months back and the price was right. It's a one man shop, ATA Auto Repair on Petaluma Hill Rd. He had my problem figured out in about 7 minutes and fixed in about 15.
 
Howdy! First, ignition timing has nothing to do with cam timing or carbs. If it is changing timing while it is running, it has to be distributor related. Is the dizzy locked down solid, and you know it is definitely not rotating? Is the base plate or the sensor loose inside? Have you checked the pin in the dizzy drive gear on the bottom end of the shaft? That would be my first guess. The pin is sheared or missing, and the gear is just tight enough on the shaft to stay "in time" for a little while. John
 
I had a 350 I installed in a 23 T bucket that did something similar. I bought a chrome dress kit from edelbrock and it came with a chrome distributor tab or keeper. Turns out, the damned thing was bolted down tight but not securing the dizzy for some reason. Not sure if it was the chrome plating or what but ended up swapping it out for the stock one.... hth
 
Does not have a standard coil has an MSD HEI coil. The hold down is working (that was my first thought) I have replaced it twice to be sure. The change in timing is very drastic. If I move the plug wires on the dizzy one post forward or back it is almost perfectly back in time. If I previously moved the plugs forward the next time it does it I have to move them backward, and vice versa. No the pin for the crive gear is not sheered off. I replaced the drive gear recently and check the pin everytime I take the dizzy out. Compression if fine in all cylinders. On a side note this motor only has about 7000 miles on a complete rebuild.
 
Does not have a standard coil has an MSD HEI coil. The hold down is working (that was my first thought) I have replaced it twice to be sure. The change in timing is very drastic. If I move the plug wires on the dizzy one post forward or back it is almost perfectly back in time. If I previously moved the plugs forward the next time it does it I have to move them backward, and vice versa. No the pin for the crive gear is not sheered off. I replaced the drive gear recently and check the pin everytime I take the dizzy out. Compression if fine in all cylinders. On a side note this motor only has about 7000 miles on a complete rebuild.
Howdy! Since you covered everything I said the first time, I'll try again. Hmmmm..... Ok, does that dizzy have a centrifical advance built into the top, under the rotor cap? I recently had a 77 Delco Remey that I discovered was stuck in the fully advanced position. The springs were still tight, but the little pivit bushings were toast, and the weights were just stuck to the base in full advance. I cleaned it up and replaced all the little bits. Works much better now. John
 
Howdy! Since you covered everything I said the first time, I'll try again. Hmmmm..... Ok, does that dizzy have a centrifical advance built into the top, under the rotor cap? I recently had a 77 Delco Remey that I discovered was stuck in the fully advanced position. The springs were still tight, but the little pivit bushings were toast, and the weights were just stuck to the base in full advance. I cleaned it up and replaced all the little bits. Works much better now. John



Something along these lines seems to make the most sense, but 45 degrees (from one plug to the next) is still a lot of change.

This is just a straight MSD HEI dizzy right? No adjustable electronic ignition spark-control modules on the side or anything, right?
 
Something along these lines seems to make the most sense, but 45 degrees (from one plug to the next) is still a lot of change.

This is just a straight MSD HEI dizzy right? No adjustable electronic ignition spark-control modules on the side or anything, right?
Howdy! Yea, somethings got to be moving bigtime here. OK. Try this one. IF it has a vacuum advance diaphram on the base, is the arm from the vacuum disconnected from the base plate? That would allow the base to float around quite a ways. JOHN
 
Yes, I've marked the dizzy to make sure it is not moving. I've even taken a chizel to put a small notch to make sure it is not rotating. At first the advance wieghts and spring were rusted a bit so I pulled them off cleaned them then put them back with a little dielectric grease, no change. So I replaced them all and greased the s*** out of them with dizzy grease to prevent any further rust or sticking. Yes, it is just a straight MSD HEI Distributor. No adjustable module, the only module it has is the one inside the dizzy that has been replaced with 3 different ones. Yes it has an adjustable vacume advance (have tried it turned in and out and everywhere in between). Yes the arm is connected securely.
 
weren't 86 350s tbi'd?
 
to my knowledge they didn't go TBI until 88 through 95
Howdy! I'm guessing that you've never had the engine opened up past the came drive stuff. Is there a chance it could be a loose/worn/damaged dizzy drive gear on the main shaft? Maybe pull the dizzy and look down the hole, maybe try a borescope to really see it good. When the engine jumps our of time, have you tried checking it with a timing light so you know which way and how far it has changed? John
 
The cam is also brand new, Installed when the motor was built 7000mi ago. The motor was taken down to the block. No wear on either the cam teeth or dizzy teeth. The timing change is around 45-60 degrees.
 
If you can, post up pic's of the dizzy hold-down area and the top of the dizzy with the cap off. I would be interested to see those areas.
 
I will get those up tomorrow. I have also tried replacing the hold down twice.
 
it looks like with the camaros, the 86 's did have tbi
 

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