Backfiring Problems

[Jeff73Mach1]

Just to be clear. I think it is ignition related and that an improperly adjusted module/pick up is a real possibility. My recommendation is to eliminate the possibility that it is a stuck advance mechanism from your diagnostic procedure with a simple 10 minute test.

Good luck and let us know what you find

 

[mustang7173]

All,

Since it has 93,000 miles on, what are the possibilities of the timing chain being stretched? Also, if it still has the plastic coated sprocket gears, it could have jumped a tooth? Caspianwendell and Jeff73Mach1 have suggested recommendations that would help eliminate possible electronic/distributor as a culprit.

mustang7173

 

[hyena429]

Could of jumped a tooth...You are at about the right milage where it is possible.....At 100,000 miles most chains should be checked for a little slack i think....Sure i seen some chains go 300,000 miles and not break.."not that it's a good thing"..But i also seen a chain get so sloppy it ate threw the side of the block into the oil.

 

[72HCODE]

very possible problem is finding out will be lots of dis-assembly.

 

[Jeff73Mach1]

If you suspect a timing chain to have jumped on a cleveland engine, you can remove the fuel pump and feel the timing chain through that opening. It takeas a fair amount of slack before the engine is likely to jump time and if that were the case I suspect it would not run well at any rpm range

 

[caspianwendell]

All,

Since it has 93,000 miles on, what are the possibilities of the timing chain being stretched? Also, if it still has the plastic coated sprocket gears, it could have jumped a tooth? Caspianwendell and Jeff73Mach1 have suggested recommendations that would help eliminate possible electronic/distributor as a culprit.

mustang7173

You must have PM'ed them cause I dont see anything on here. and the only way to eliminate is readjust the module. if it's set at .030 it's too much gap. Timing chain will have problems through out driving range including hard to start...but, I have come to find that with engines...anything is possible

 

[71_resurrection]

timing chain is only a couple thousand miles old.

 

[Justin71]

I was having some similar type issues - which came at me rather all at once it seemed. Ultimately, I found a significant vaccum leak between the intake and carb. I really recommend you just plain old put a vacuum gauge on it. If you are below 18 - you have a leak and it flat-out needs to be found. More details/reading here: http://www.7173mustangs.com/thread-after-firing-when-off-throttle

My situation was somewhat different than yours, but one question i have is, is it really a full-blown "backfire" (like flames coming out of the carb) or maybe just an "afterfiring" as I called it? only infrequently was it a real gun-volume bang. Mostly, just a little blam, blam, burble, pop pop type thing. Mostly my issue was vacuum and that is easy to check.

otherwise I would just try an old style points and condenser dist in there and see if that old pertronix has croaked on you.

Jay