Hey crew, I'm helping on Nooches 54 pontiac, straight six flathead powered. Here is the score: 1. we are getting spark at the spark plug. 2. timining is set to 0' (not advanced nor retarded). The symptom is that you turn the motor over and it constantly backfires up through the carb (2 barell Carter). We have adjusted the timing all the way from 10` retarded to 10' advanced with no real difference. So what gives? What generally causes a motor to fire up through the carb and not run at all? I initially though maybe we we put the dizzy in, we got it 180` out? Danny
Dizzy being 180 would do that... and as simple as it sounds even messing up the firing order would do it.. I know, i know..thats something thats so simple we can ussually do it with out eye's closed..... but i've goofed em up myself . it happens
Start with the basics.Pull #1 plug and bump it around to compression and 0 TDC,check rotational direction during thi step.Check rotor position and firing order. If it still bangs could be any # of things.Is it a new motor, old motor?Are the points closed up,is the valve lash correct,are the valves all free,are the guides good and tight,is the cam timed correctly?Yada,Yada,Yada. Good luck and G,day.T.OUT
keep in mind that if an engine backfires through the carb it's because a cylinder fired while the intake valve was open. how can that happen? timing problem. stuck valve. etc. using this basic knowledge makes scopin' the problem out a bit easier. it really is all logical, even though sometimes it doesn't seem to be.
Was the car running before or was it not a runner are you trying to get it running now? I was****uming it was running before..
Thanks to Danny for posting this for me - we had it running (barely) months ago but the engine kept cutting out, seemed like it was flooding - so we put on a reco'd carby, new starter, leads, plugs, coil and rotor,etc in an effort to clean up everything along the path to get her going well. thanks guys - keep em coming nooch
So it was running bad, but not backfiring through the carb? If it wasn't backfiring through the carb then, i would go over everything you fella's did step by step. Especially the distributor phazing. Finding TDC as mentioned up a way's in the thread is where i'd start..followed by firing order. good luck guy's..
Hey Guys, Ok this is the lowdown: 1. found top dead centre 2. put on the spark wires in the correct order (which is stamped on the block and also matched the service manual). double checked. 3. tired to start. motor turns over but never runs and its almost like bang! bang! bang! out of the carb. 4. the timing was at 10 retarded so we adjusted to 0` with no difference. then adjusted to 10` advanced. all this was done in 1` increments. when the carb back fires, you can see fuel being spewed out of the throat of the carb. im wondering if the timing is really 180 out, wont it be firing the plug on the intake stroke, pushing the fuel back out? thanks crew! Danny
You sure it isn't the fuses on either side of the motor? Or the one betwixt the steering wheel and front seat? READING MATERIAL! http://www.recarbco.com/technical/newtrouble.html http://faq.f650.com/FAQs/CarbMiscFAQ.htm http://www.ford-trucks.com/forums/archive/index.php/t-146958-Arrrgh%21%20%20Carb%20spewing%20gas%2C%20won%27t%20start You can muddle thru it and piece it together..........I'm too lazy! xxx
Hey Danny, Have ya checked for a stuck intake valve.......if you know you're electrically correct, I'd sure be checkin that..... Have you brought it up to TDC on the compression stroke and checked which wire the rotor is pointing at???? Some engines you might be only one or more teeth off on the dizzy instead of a full 180........
hey brandy, what would the fuses do? we are getting fuel to the carb and spark to the spark plugs. am i missing something? you and you mysterious tech "help"...im beginning to wonder if you just dont go around sewing the seeds of doubt... xxx
At BilletProof I was standing there with a guy and his Model A coupe. NICE CAR, this lug walks up and points out the master cyl. Says that came off of a 70's pickup. I said NO ACTUALLY that came off of a VW. He fell for it. It's not WHAT I SAY, it's HOW I SAY IT!........oh and he was right. The fuses I'm talking about are the two AUSSIES standing on either side of the motor. JOKE man JOKE! Read the material I posted for ya. xxx
It's 180 out just had the same problem with mine Spun it around , changed the plug , and it ran like a champ
Hey Psycho, Bring the motor to TDC, remove the dist, rotate it 180 deg and drop it back in. Should do the trick man !! Rat
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