backfire / rough shaking acceleration - the show is tomorrow !!!!!

The one show i look forward to in Atlanta is tomorrow, - as in, sunday the 9th Oct.

My car was backfiring and stuttering when i got on the gas around 35 + miles, . ..... . off the mark it was fine through the gears.

I replaced my fuel filter.
I cleaned my carb, and replaced the accelerator pump [ Edelbrock 1405 ]
I checked my timing
Pulled the distributor and checked for play, seemed ok.
played with fuel mixture.

After cleaning the carb it did run slightly better, the car died after a small cruise and now the car is running rough at idle and in gear.

I noticed one thing when i was checking the timing. . . . . . . . the white line sits right at the mark, every so often the car surges a little and the white timing line advances a little, - makes sense ?

This made me think it might play in the distributor, but it checked out.

Help me, please, this ****s, i really wanna drive my car tomorrow

L

 

Check your plugs and your points.

 

Bad coil or condenser

 

Sorry forgot to add i have a pertronix module in the stock dizzy

Can a coil do that ?

L

 

A bad coil can cause a motor to run as you have described.... Ask me how I know....

 

Swapped out the coil, still runnin rough

L

 

sure the floats not sticking? or the choke is opening? smell real g***y when its running? any black smoke? backfire and ruff idle could be 2 crossed wires too, bad coil, bad module or in yourcase pertronix could be taking a ****.

 

I wondered about the pertronix unit, but i always thought that they either work or didnt work

The timing mark jumping has me thinking its the timing chain

L

 

Most likely fuel or spark . . .

If the timing was 'jumping around', what you may be seeing is a miss in the ignition. I'd turn the throttle up a bit to about 2,000 or so and then take your timing light and look at each plug wire (***uming it has an inductive pickup). Once you see the firing/flash patten . . . see if it is the same on all plugs and wires.

This is obviously not a load test, but it has found many bad things for me in the past for a situation like yours where it doesn't even sound right at idle.

 

sounds like spark to me-check plugs AND wires

 

first thing I would do is a compression test. THen I'd pull valve covers and make sure the valvetrain looks good...all rockers moving the same amount when the engine is running, and look at all the valve springs to make sure none are broken.

 

you beat me to it. check for a dead cylinder. push rod, spring, broken ring will all give these problems

 

.......what squirrel said; sounds like a broken valve spring.

 

Plugs are fouled, first one i checked compression is around 135 , gonna go check em all now

 

Thought i'd post a update for anyone else having this problem.

It was the Pertronix Module, it was bad, . . . . . . i went crazy finding this out though, i never knew they would "go bad"

Thanks everyone for all your help

L

 

Timing chain

 

Good you found the problem!

Put points back in it, at least you'll suspect them right away

 

i hate electronic ignition. one went bad on me and i thought the same as you, i thought either it works or it dont. damn car would drive and soon as it got warm it would die, let it sit for a sec, fired up and then died when warm again. took me forever to figure it out to.

i dont think ill ever run that electronic ******** again. points are easy to adjust and are cheap to replace.

 

Strange I ran Pertronix in my Cad for a day. Back to points the next.

 

Happened to me recently, same drill.
I cracked a vacuum line at the base of the Holly carb. It gave me fits for 2 weekends trying to find the leak.
The crack was on the underside of the rubber line off the carb so I couldn't see it from the top looking down.
Pull each line and look closely at each one with a strong light.
Vacuum-Leak test it with propane too or starter fluid to be sure.

 

Bttt .

Car is still running bad, i aint driven it much at all since i put the new pertronix module.

Started it up, drove around the block and by the time it had warmed up it was running like ****.

Gonna put the points back in tomorrow and change my plugs and wires, . . . . . . i checked my compression and the cylinders are reading around 125psi.


L

 

Make sure vthe primary wires to the coil are not hooked up backwards. It will run, but the ign voltage will be weak.

Disconnect & plug your vac advance when you are road testing the car.

 

Did you make sure the floats were not sticking, I had an edelbrock carb on my olds and rust got through the filter and plugged the jets and gummed up the float causing it to stick.

 

I got 50¢ on the distributor cap. For laughs, start it up in the dark to see if you got anything arcing.

Bob

 

Does that mean it runs good cold? Plugs still get fouled? To me that means choke -- has plenty of gas to run good cold, too much gas to run good warm.

Pete

 

Have you pulled the rocker covers and checked?

 

EVerything looks good under the covers . I checked the distributor against a new one and it seemed to to have some play . DRopped in a new dizzy and I can't seem get the car running. I got tdc and set the rotor in the right place . When I turn the key off it kicks back which I guess means I got to much advance .

But all this has me thinking my timing chain has jumped.

I have no spark at the plug or coil .... I'm going to set my dizzy again to double check ......

Ideas ?

 

I have a single point delco on my big block. It never causes problems. However I just noticed last night that the coil has sprung a leak!

 

Found out the rotor wasn't seating itself because of the pertronix magnetic sleeve. I cut it down an 1/8th or so and it fired right up . . . . . . . she sounded great

Un-****in-believable, it took me a month to discover this, i had the same set up for 3-4 years and didnt have this problem

thanks for all the help

 

^ so ummmm, yeah, ... .. it wasn't that.

Been ****in with this engine for a month now, changed the plugs, rotor, cap, points / pertronix [ new unit ] , wires, checked TDC many many times . . . . . . . . fuel mix, carb is getting fuel. Checked some of the plugs and spark was weak.

Pulled the distributor for the 34th time and re-checked my TDC rotor etc. Got in the car and she ran for the first time in weeks, let her warm up and started playing with the timing, idle and fuel mix, . . . . she was still running roughish, but it sounded like i was getting somewhere. I shut her off after feeling like i had gotten somewhere . . . . . . . . went to crank the car a few mins later and she wouldn't run,..... same **** as the last month. This timeafter i turned the key off the engine would kick back really bad. I tried playing with the timing, but i know im right on it, . . . . . again i check my rotor and TDC is right on, i got no slop in my chain.

Then . . . . . . . I tried to start her again and i got nothing, at all, 12v on the gauge,........ looked around and wiggled the ignition wire on the solenoid and it started, . . . . .

Could i be having an electrical issue that is not allowing the engine to run ?

Could an ignition switch or solenoid do something like that ?

Help me please