76Cutlass_442

Hello, i have a 76 442 with a 95k Original Miles 350. The 350 has a few mods, Edelbrock Performer intake, 600 Cfm Quick fuel Slayer carb, Hedman Long tube headers, with X Pipe to Flowmaster 50s. A couple days ago my car started to Shudder/Jerking when accelerating. More or less happened when the car was warmed up. With the Car Accelerating it would seem like there is far less power and the car just jerks and does not run good at all. The car has new AC plugs, the Auto-lite Wires are about 3 years old along with the Cap and Rotor with only about 4000 miles. Also the Float levels are in the middle of the sight glass on both Primary's and Secondary (Quick Fuel Recommended). This jerking only started about a week ago.. Please help!

76Cutlass_442

Hello, I have a 1976 Oldsmobile 442 Equiped with a 350 with 95k Original Miles.. Couple Days ago the Car started like Shuddering/Jerking while accelerating from a Stop or Gaining Speed. I am not sure what it would be i tried leveling off the Float Levels, Idle Mixture.. and the AC plugs are fairly new.. this isnt no tiny shudder. i wouldnt really lose speed it would just Shudder. i noticed that the Idle is a little off too. Could it be a Vacuum Leak? The Cap, Rotor and Wires are all about 3-4 years old with only about 4500 miles on em.. The motor isnt completely Stock. It has a Edelbrock Performer intake, Quick Fuel Slayer Series 600 cfm Carb, Hedman Long Tubes, and X Pipe to Flowmaster 50s.. Somebody Please help me!

76olds

Hate to say this but my timing chain went out around 97k miles on my 76 350. Have you tried taking the distributor cap off, putting a socket on the crank bolt and crank it back and forth to see how much the rotor will move? Its possible the chain has jumped a tooth. It would have to be a substantial vacuum leak and you would hear it to make the car shudder and jerk. Do you hear any backfiring when you blip the throttle?

76Cutlass_442

GEARMAN69

Is the HEI distributer original 1976 below the rotor? , if so the magnetic pick up coil or module, coil cut be crapping out and shorting? Sounds like a new HEI would fix it

GEARMAN69

Possibly a bad distributer if it is the original HEI, check the magnetic pick up and module stuff and if it is the old GM module and crusty windings on pick up coil either tear down whole dizzy and replace parts or buy a new complete unit on ebay

Indy_68_S

Put a timing light on it.
When my timing chain went (@ ~ 150K mi), it started shuddering/missing one day and the next day I could barely start it. It had similar symptoms plus (like 76olds said) it would backfire (thru carb IIRC) when cranking.

gs72

Check fuel delivery. Poss. Plugged fuel filter or weak fuel pump etc. warm up the engine, take the fuel line off of the carb and point it into a container. Run the engine briefly and see how much fuel you get in 30 sec. It should be over a pint. Inspect fuel filter also.

oldcutlass

No need to open multiple threads on the same subject. I merged your 2 threads. Firing order on an Olds engine is ccw, do you think you may have crossed a couple of wires?

cherokeepeople

gearmans on it.pull the cap and rotor.under the rotor is the pickup coil.it goes around the distributor shaft and has 8 points on it.check the wires from the module to this coil.what happens is as the vac advance kicks in and out this flexes.thru time it will break the wires right where they go into the pickup coil.when advance kicks in it pulls wires apart and car dies,loses vac wires go back together and car runs again and the cycle continues.pull the vac advance hose off plug it and go drive it.if it runs ok replace the pickup coil.

76Cutlass_442

i don't think so because i have not done the plug wires yet. im building a set of Accel's for it. i usually just do one at a time anyhow. Sorry for posting twice, just frustrated. i have not checked the timing since i owned it but it was timed when the timing chain was replaced about 3 years ago. Thats also when the Wires,Rotor, and Cap were replaced as well..

Octania

The fatigue fail of the flexed wires in the dist'r is my chief suspect also. Hard to spot, easy to fix.

" i usually just do one at a time anyhow"

It might be time to master the technique of starting with a bare distributor where you don't know where #1 is, and learn to find TDC #1 compression, and put all plug wires on in order. It's not complicated when you understand what is going on there.

GEARMAN69

the wires in the internal wiring harness for the mag pick up not the spark plug wires. The ones from the module to the pick up coil because when the plate moves from the vacuum it is moving the wires , seen it happen myself. Pull dizzy and put in a vice remove roll pin for drive gear and slip shaft out then replace pick up coil and replace module if it is still old and GM marked

76Cutlass_442

is this a pretty simple procedure? Sorry i have never pulled out the Distributor on any vehicle..

GEARMAN69

Well it is not bad but consider having a experienced friend over to do it with ya.

Mainly just make not of rotor and housing position when it comes out, be sure to have cap and wires off but laying to the side , you may only need ot pull one or too wires to move it out the way so the rest can stay in sequence. Probably easier for you to get a new one on ebay cheap and just swap it but before buying anything just get cap off and good light up close and look at condition of the wiring below it may be crumbly and falling apart. Do what he said and unplug vacuum advance and drive without and see if it does it.

76Cutlass_442

Will do! i will post back on Updates. Thanks

76Cutlass_442

This was the Distributor i was going to replace it with if need be. This was recommended by a friend of mine. http://www.skipwhiteperformance.com/...px?Item=6503-R

GEARMAN69

Thats cheaper than buying small parts for yours ! LOL

oldcutlass

Skip White stuff had a good reputation in the past, can't beat that price. You need to call and ask how much mechanical advance is built in to his distributor.

76Cutlass_442

Will do!

76Cutlass_442

Ok so i called Skip White and they said they would get back to me if i left a message.. they never got back to me. i took my cap and rotor off to look inside the distributor and everything looks just fine. No damaged wires, and the weights looks fine. i did suck on the Vacuum Advance and after a few seconds i could not suck anymore... Which means that would be functioning right? i put everything back together and figured i would check out the Plugs just for the heck of it.. cylinders 1,4,8 all had Fouling (not oil). i cranked it back up and it was idling rough still and still had the problem..

76Cutlass_442

Turns out it was only 3/8 spark plugs were fouled (not oil)... thats weird considering i had just replaced them a month before..