Carby Problems (Backfiring through carb?) - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

siwren · 07-19-2004, 21:57

Hey All,

since messing about with an electronic ignition setup but going back to points, my car has been coughing (backfiring) throught the carb. It doesn't stall, but happens when I get on the gas, get off and then back on.
Its irritating and concerns me that damage might result.

Any ideas what i might be?

Also, my battery somehow managed to spray acid onto the underneath of my bonnet which then dribbled onto my new rocker covers and ate the chrome off. How could this be happening. The car starts fine with plenty of cranking power and there are no vent holes for the acid to escape.

Is it overheating or something?

Thanks

Simon.

brenx · 07-19-2004, 22:43

Sounds like either a lean state or incorrect ignition timing. You tried advancing it? Turn it clockwise. Have you been static timing it or timing with a timing light? Static on electronic ignitions very hit and miss. With points its reasonably accurate.

In regards to your battery. Is it loose? Maybe it's boucing when you go over bumps.

Brenden

siwren · 07-19-2004, 22:52

The electronic ignition is gone and the points are back. The problem is that there is no timing marks on the balancer, they've either fallen off or were never there to start with. This made it difficult to get the timing right.
Is there any way to me to get it right without the timing marks on the balancer, or is it a case of tinkering with it until I get it right?

I'll check tha battery tie downs tonight.

Simon

brenx · 07-19-2004, 23:00

Sand the balancer with 300-400 grit sandpaper the marks will be there. They'll have just been filled with paint.

You can do it without the marks on the balancer but it takes a $400 timing light that has the total timing on it.

Brenden

Work Horse · 07-19-2004, 23:47

Yer I agree with Brenden the timing marks are probably there. The one on the balancer is just a nick, I would mark it with white paint or liquid paper when you find it.
If you get your rotor button pointing to spark plug lead number number one, when piston number one is a the top of its stroke, you should be able to find the timing mark on the balancer somewhere near the timing pad on the engine front cover.

The battery sounds like it is boiling. Get an auto elec to check your alternator, sound like it or the regulator are knacked

siwren · 07-20-2004, 02:09

WH, you might be right the lights go dim and flicker when idling low and the indicators hardly flick until the revs rise. I'll get it cecked out on the weekend.

Clevo_land · 07-21-2004, 01:57

Is it possible that the backfiring problem is due to too high a fuel pressure? ie excess fuel in carby? Timing would generally cause backfiring on start-up aswell and it would be hard to start.

JG33PY · 07-21-2004, 15:29

i have exactly the same problem except my timing is spot on 6 btdc. points gap is right, plugs are gapped at .033". i'm using a 3310-3 vac sec holley which has just been rekitted with 68 jets and 65.5 power valve.
i'm just about out of ideas.
when accelerating gently it dosn't backfire but when stabbing the accelerater hard it back fires through the carb. it also runs on after turning ignition off.

siwren · 07-21-2004, 15:46

Well I'm glad I haven't got the same issues as you Nak, it only backfires every now and then and I get no run on. It doesn't back fire on startup and starts okay, just concerns me that I'll need to get moving quickly for some emergency or something and the car will let me down.
Anyway I'll tinker with it this weekend.

JG33PY · 07-21-2004, 15:51

i'm thinking i'm over carbed. i'll try and hunt down a 600vac to see how that goes.