Will not idle runs rough backfires 1980 accord 48,000 miles

There is a belt called a timing belt that has to be replaced about every 90 thousand miles. If you don't replace it, then it can slip and cause the issue you are describing.

Think ur fuelpump or regulator just blew. Also inspect idle control n tps

If it's running rough, chances are that it's misfiring. If the Check Engine light is flashing/blinking, it is definitely misfiring.
If that's the case, drive it as little as possible... Or straight to the mechanic because the more you drive it while it's misfiring, the higher the chance is of you ruining your catalytic converter.

I’m happy to help further over the phone at https://www.6ya.com/expert/jason_00b31cc8f593773a

hi.
go to this link might help you get it sorted.
Honda Accord Rough idle right after starting Google Search

For this types of problem,there are few help inks to troubleshoot the problem.Click the link below to go through the troubleshooting procedure to resolve the issues :----Idles rough and quits when gas pedal is pressed less? http://technoanswers.blogspot.in/2012/01/1999-ford-f-150-idles-rough-and-quits.html-----------van idles rough? http://howtobyme.blogspot.in/2012/01/2004-ford-freestar-van-idles-rough.html
--------------runs lean and idles rough? http://technoanswers.blogspot.in/2012/02/ford-runs-lean-and-idles-rough.html
-----------Car still runs Rough after tune up? http://howtobyme.blogspot.com/2011/12/car-still-runs-rough-after-tune-up.html
------------Idle flair is noticed on car? Rough idle? car will not idle? Erratic idle speed? http://technoanswers.blogspot.in/2012/02/idle-flair-is-noticed-on-car-rough-idle.html
----------High rpm in neutral? Inconsistant high RPM in neutral? http://technoanswers.blogspot.in/2012/02/high-rpm-in-neutral-inconsistant-high.html
------------Engine Backfires? http://technoanswers.blogspot.in/2012/02/jeep-backfires.html----------- Nissan stalls and bucks on Acceleration?

http://technoanswers.blogspot.in/2012/02/nissan-pathfinder-stalls-and-bucks-on.html

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Nissan Pathfinder Backfires? http://technoanswers.blogspot.in/2012/02/nissan-pathfinder-backfires.html
---------How to adjust rpm? http://schematicsdiagram.blogspot.com/2011/12/how-to-adjust-rpm-on-2009-dodge-charger.html
------------Engine cuts out at 3000 RPM? http://schematicsdiagram.blogspot.com/2011/12/engine-cuts-out-at-3000-rpm.html
----------This will help.Thanks.

Check for a vacuum leak, at the intake manifold, and at the throttle body. How old are the plugs and wires? Its the age not the miles. Has the fuel filter been changed?

I know you mentioned the EGR valve has been replaced, but you may have a bad 'new' part. I know the car is electronic, but has anyone checked its ignition timing (timing belt been looked at, I know it only has 77k on it). Is the fuel pressure regulator OK and it vacumm supply?

check the engine temperature sensor.

I Have a 1999 ford f150 4.6 that back fires and is just running really ruff when idling alot of nack fire a sord of like a pulse going on what is my problem?

Idle is rough because not a right Air/ Gas mixture.
The ideal air /gas ratio is 14.6:1. If less than that it has rich mixture. If it more then that it has a lean mixture.
Back fire happens when accelerated because of of rich mixture pumped out at exhaust cycle is burning.
At speed above 40 miles/hour, temperature and fast compression cycle make the problem is less obvious.
Cheap first shot is to replace the air filter to correct this ratio. If it doesn't help, need Fuel distributor service. ( However people like to make easy money from you first, they will convince you for a turn up) Good Luck. I'll check back to see how the progress going.