pops and bangs when accelerating

One fouled plug (bad extender) and your distributors need the advance lubricated.....and some fresh fuel, use stabilizer if you are not going to drive it more...

 

I agree with Big tex, same thing happened to me last year. You should maybe Synchro the carbs while your at it, and adjust mixture, and clean the jets.

 

could also be the gas.

 

See post above, lightly driven cars these days are sitting ducks for fuel seperation and the boundary layer is nasty

 

Especially with E10 gas. I try to drive mine 2-3 times a week.

As for the OP, I had a little popping and backfiring the other day leaving work. Pulled plug wires and extenders and reinstalled with a little dielectric grease. No more problems.

 

I haven't heard of this separation...ethanol-related?

I've never had a problem with short-term storage and engine starts here.

 

I concur 100% Big Tex, most likely electrical masquerading as a fuel problem. I have become something of an expert in snorting and popping carb cars in the last few months. Symptoms sound like a cylinder is not firing, unburnt fuel is making the popping and banging when it subsequently ignites in the exhaust, probably snorts and crackles on the overrun, too. A plug probably got fouled on start up.

OP may want to pull the plugs and put in a new set. Heck, plugs are the cheapest thing one can buy for a Ferrari! Then run it pretty hard to get it cleaned up, warmed up, and happy again. My 308 is doing great with those NGK BPR7EIX plugs, though others may have better recommendations.

If you are lazy, and lucky, the offender might be one of the back 4 plugs. Otherwise, you'll be trying out your various 3/8" drive extensions, pulling the front bank plugs by reaching through the gap between the engine lid and rear glass. It ain't so bad once you've done it a time or two, or ten!


Good luck! Jeff

 

As the old saying goes, "95 percent of carburetor problems are electrical."

 

+10000.

Sounds like an ignition thing.

I had a weird misfire that was driving me nuts for a while and it turned out to be.....wait for it...........a bad extender that was arcing. Those things are cheap plastic crap and they fail all the time.

Go for a drive, then pull the plugs and give them a look. You may be able to figure out which cylinder it is based on nothing but simple observation of the plugs.

Birdman

 

Dave Helms has done extensive research, he HAD to......the fuel line kits at Ricambi are the result of his findings.

The real trouble is the boundary layer between the seperation is very corrosive to our aluminum tanks and the pinhole leaks we are seeing in the older cars is the result.

Not good.

 

On the carbed cars I always warm up idling pretty high, the OM says 3K RPM and that's not far off.

And once a plug is fouled it rarely cleans up enough to solve itself.

NGK BP5ES here, that's a hot plug but intown stop and go you need it, for track use cool it back down a few levels, to a 6 or 7....

 

BigTex, I got one word for ya. Iridium. Seriously. They are heaps better than old school spark plugs. They foul less, they start easier. I was a skeptic but I'm not anymore.

 

I'll give 'em a try, but I think the fuels are bringing old varnish out of the whole carb system, and asking the poor plugs to burn a lot of crap.....

Besides, everyone comes out to talk to me at the apartment, when I'm 'under the hood".....

Chinese guys walking the dog, hot Italian chick visiting a friend....

 

pinhole leaks...bad


So when is Dave going to provide tank replacements/liners.

thanks Tex!

 

NEVER! I have already identified enough ways to disolve perfectly good money doing all of the hoses... I need not head down that path!

Thirty (30) days.... mark it on your calander, tank damage is preventable and I have delt with many in recent years. The car starts and goes for a short drive every 30 days. The days of being concerned about driving the car until the oil temp is up to operating levels are gone. That is now a secondary concern and will just require more frequent oil changes to deal with the acid build up in the sump from short winter drives in the snow belt area.

The alcohol and water settle to the bottom where the fuel pick up is, when separation occurs. These cars were designed to run on gas, not alcohol and water. The resulting debris we are now finding in carb bowls is ugly.... when that happens to a CIS car..... the passages in the fuel distributors simply cant pass those particals and cant deal with corrosion.

I designed and built a prototype tank turn over system but that sits on the shelf waiting for the day the market demands it. There are many that still dont believe this problem with the hoses and tanks is real..... it is and you can thank the Fed's for bringing you even worse fuel in the next two years. In that period of time 15% advertised (likely closer to 20% realized) will become the norm and we will wish for the days of the Rabbit Pee fuel we now have.

 

Dave, if I pull the cats and go to a straight-pipe, can I run 100LL aviation fuel in my 328? I used to have an ethanol-free gas station nearby, but they no longer carry anything but 87 octane. I don't trust either octane boost additive nor ethanol stabilizer for the "rabbit pee" we're stuck with.

Sorry for the brief hijack.

 

Nice info, Dave...definitely an undiscovered problem for me. I plan to be rebuilding my fuel system soon enough, when the budget expands a bit.

 

Evil Hijacker!!!

You just need to get better rabbits.

 

I have used Stabil in cars/bikes/boat engines for years and have had no issues with current fuel sitting for up to 7 months. Usually it's more typically 4 months.

Stabil claims that their product will eliminate the separation and other gasoline degradation issues. I certainly can't verify that scientifically but my experience seems to agree with their claims. Or maybe I've just been lucky.

 

So long as they don't bite the dust

Must be getting old; had a 20 something completely miss the "rabbit test" reference the other day.

 

There is sound reason the USCG outlawed aluminum fuel tanks. One cannot walk away from a burning boat.

The chemicals that were once very effective at eliminating all separation are now highly questionable in my mind. My testing on these has been minimal as chemists I have consulted with on the matter strongly doubt one product could cover a moving target such as this. Never say never.....

We used the aviation fuel in race cars where having a constant with low octane was a requirement.... too high an octane makes for too slow a combustion for a race car. The most power is at a point just before piston melt down and detonation. Two airports we used finally put the stops on the practice as the DOT started watching for it.

 

"There is sound reason the USCG outlawed aluminum fuel tanks."

Dave, are you sure about that? There are many suppliers that claim to provide "USCG-approved" AL tanks. In fact, old Hatteras boats, which were built with integral fiberglass tanks are now having those tanks in the gas-powered boats cut out/replaced with AL tanks.

Ironically, when they were built, the integral FG tanks were the ultimate material - and would last as long as the boat (they still will for diesel boats). Of course, that was in the pre-ethanol days, before gasoline (or what passes for it nowadays) could dissolve the resin used then...

 

Since we are off-topic anyway....I run Premium in my car. Given that the fuel thats available here now is coming with more and more ethanol in it is there really a benefit to using premium any more or would 87 run just fine?? I know that the Compression Ratio should be fine with the 87, but I have felt safer with the premium.


Thoughts on this one??





PDG