Machine gun noise when accelerate then a backfire occasionally

[Hugomartin]

87 5.7 350 Tbi.... any ideas what it can be I’m trying to post a vid from my phone not sure what icon to select thanks for your help

 

[78C10BigTen]

Sounds like bad plugs, wires, plug wire connections, possibly plug wires on the wrong plugs... back fire may be a tbi rich condition...

 

[Hugomartin]

https://m.facebook.com/story.php?story_fbid=10225751268503967&id=1098687856&fs=0&focus_composer=0

 

[Hugomartin]

Sounds like bad plugs, wires, plug wire connections, possibly plug wires on the wrong plugs... back fire may be a tbi rich condition...

Thank you my plugs n wires are fairly new though I’ll try with the tbi adjustments. I tried rotating the distributor cap slightly to retard the vacuum advanc

 

[Hugomartin]

https://m.facebook.com/story.php?st...comment&notif_id=1627050893724175&ref=m_notif
That machine gun tweet noise what should I look for ? This is a better video thanks. God bless

 

[82sbshortbed]

Definitely a electrical problem imo. Load your video to YouTube then post it so more guys can see it. You'll get more ideas of what it is causing the problem.

A lot of guys here don't have Facebook and can't see it.

 

[MrMarty51]

Is the AIR injection smog system still hooked up.
If the check valves in that system got messed up they would backfire on decel, sound like a cannon went off.

 

[PeteJr]

Sounds like you must just be passin' through Memphis............

 

[Hugomartin]

Well thought I’d give an update I first replaced the egr valve I didn’t notice much in change idling or driving I’ll list what I’ve started fixing
1 egr valve
2 engine coolant temp sensor
3 ignition coil
4 distributer
5 cap n rotor and plug wires
6 water pump
7 fuel filter
8 fuel pump my pressure was around 10psi before the swap and didn’t seem to increase when I reved in park
9 starter

I think it ran a little smoother with new duralast distributor not much though and it was a pain to research! 13 degrees before tdc on compress stroke was what worked For me any thing else it wouldn’t start! After changing the fuel pump to another ac Delphi it ran slightly better but mainly for peace of mind. My plug wires couldnt tell much maybe better. The new starter was a car quest model , the old starter was car quest and was actually made for manual transmission , I have an automatic. The new starter seemed to have more juice and fit without any shims like the manual transmission starter.

my dilemma is the truck occasional Boggs out and dies say on second or third ride of the day after I start it I’ll drive to a stop sign and idles a bit slow I had to make adjustments and markings on my idle screw ALOT
And played with my advance and retard on the dizzy cap ALOT. I think the main secret is getting the idle adjustment in balance with the distributor adjustment. Next I may try to clean my idle air control. And try to figure out why the where my ignition coil harness plug has a wire shorted from the plug with electrical tape not sure who or why they’ve done that

 

[Juggernaut]

Believe it or not, my 94 dually was doing the very same thing. My 454 would hammer like that then start back firing after it had been running a while. Couple times the engine died and wouldn't restart until I let it cool down, then it would start right back up. Took me a while to chase down the problem. Turned out to be a bad ignition coil! The coil tested good, and it was an Accel coil that was only about 3 years old

 

[Corvette Ed]

Sounds like you must just be passin' through Memphis............

...better known as the ass end of Tennessee.

 

[Corvette Ed]

Welcome to the forum.

 

[PeteJr]

...better known as the ass end of Tennessee.

Pretty much, Ed...........