Ignition System

[Big Jim]

Backfiring in the exhaust can be caused by a number of things.

 

Air leaking into the exhaust system.

Too rich fuel mixture, (usually at idle) so unburnt fuel is still hanging around in the exhaust and ignites now and again.

Choke stuck on.

*bleep*ty crappy pancake filter making carb overfuel.

Timing being out.

 

Timing is different depending on how your engine is set up, if you've got a "fast cam" or not. (Dave Andrews website explains all about this, link from our website)

My book says 10º BTDC for a standard 1600cc engine at idle, that without the vac pipe attached (plug it) you may have to either back it off to 8º if it "pinks" but I doubt that it will.

Check the timing with a decent timing light. This type is worth their weight in gold, stay away from the cheap ones.

Whilst you have the timing light on, rev the engine and see if it advances more, that proves if the weights are working inside the dizzy, then attach the vac pipe and rev it again, it should really advance up then steady out, that proves the vac unit is working.

[Grizzly]

Thanks Jim (and all),

OK I'm onto this now. Here's where I'm up to:

Basically, I think the engines just settling in and I need to address some issues.

Over 800 miles now and the oil's still clean. I think it's a good sound engine.

It's a 2 litre Pinto by the way. When I initially checked the timing it was absolutely miles out. I'm talking 30 degrees plus!

I'm wondering now.... I don't think the cams anything other than std, but I really should check just in case.

Last night after a run out, the engine seemed to be very warm, but not indicating as such on the temp guage.

I just happened to touch the rubber bleed cover next to the thermostat housing and it split! Water everywhere! I don't think it had lost any beforehand though Anyway, I drained it all down as I've got a new 88 degree Thermostat to put in - Still need to get a replacement bleed cover though. I've also bought a new 13lb Rad Cap.

I've got a new set of manifold gaskets (Inlet & Exhaust) and a carb (32/36 DGAV) Service Kit to fit.

Once I've done this little lot, I can turn my attention back to the timing and my ancient strobe light.

I think I should probably fit a new Cam Belt (& Tensioner). The one that's on must be at least 5 years old. The trouble is, two of my local factors say they're not listed for a 1990 Pinto Will one of the many on eBay be OK?

Finally, I'm then thinking of having a trip over to Boggs Bros (They're highly recommended). The chap there (David) has already told me on the phone for starters, that the carb will be incorrectly jetted due to my Pipercross Air Filter. It's not that I want loads more power, I just want to know it's all set correctly. Therefore I really think I'd benefit from their set-up expertise in finally getting it to run really sweet.

 

Oh, and I've got to decorate the lounge apparently!

[Guest chris brown]

I think I should probably fit a new Cam Belt (& Tensioner). The one that's on must be at least 5 years old. The trouble is, two of my local factors say they're not listed for a 1990 Pinto

It’s the same cambelt as any other 2ltr pinto and yes worth changing the tensioner at the same time, not that I’ve ever heard of one going unlike the modern plastic things.

As for the popping back in the exhaust, you will never get rid of it all due to the fact that there is very little back pressure

[NeilD]

Oh, and I've got to decorate the lounge apparently!

 

better hoover the garage carpet while you are at it

[Guest salty_monk]

If you're going to boggs brothers you should get them to fit a set of bike carbs

[Grizzly]

New Cambelt & Tensioner now fitted. Re-timed at 10 degrees. Overrun backfiring is now very much reduced.

 

Thanks to everyone for their advice. It really is appreciated. :good:

 

PS. Living Room decorated :D