Engine has no power

36 posts · joined Jul 2007 · 17 Nov 2009, 7:53 am

#747790

Hi all, I posted a problem a few weeks ago (air in fuel lines) and am still having the same problem...

I recently swapped 1600 engines in my fastback. The engine now runs smoothly when idling and at high revs but as soon as I get the engine to do any work (changing to 2nd gear or driving up a small incline) there is no power and the engine stutters and bucks and I get the occasional backfire.

I assumed it was a fuel problem, but I've overhauled the fuel system and still get the same problem (carbies need tuning, but I got the same problem trying with a different set).

I've given the engine a tune up too, including points, gaps and timing. Compression is ok.

Could it be something with the ignition system? What could cause this problem only when the engine is under load?

Thanks.

dangerous 23 Windows of Awesome

5,901 posts · joined Jan 2005 · 17 Nov 2009, 11:23 am

#747809

"most ignition problems are carby problems"

Well, that is not the exact quote,
nor is it gospel,
but it has been true in a lot of cases for me.

I would focus on the tank and lines delivering the fuel to the pump,
and make sure there are no filters that are clogged.

Also possibly the fuel pump itself.

If you are confident that there are no cloggd jets in either carb sets,
then look at ignition faults.

All this assumes that basic tune-up and maintenence stuff has been done on both fuel system and ignition.

westi wrote:That's mad Alan.

matberry Moderator Go hard or go home

8,114 posts · joined Mar 2006 · 17 Nov 2009, 11:29 am

#747811

Have you also checked the valve clearances? I've seen riding valves (no clearance) do similar strange things, it's a must check base tune necessity.

Matt Berry Motorsports...air cooled advice, repairs and mods Ph 0408 704 662
OFF-ROAD,CIRCUIT,DRAG,STREET,ENDURANCE

Carter Seriously Crusin Dubber

104 posts · joined Oct 2008 · 17 Nov 2009, 3:36 pm

#747838

if you right out the fuel stuff... check your coil, they do funny things at high revs if they are buggered... mine was doing the exact same thing... wrote out everything fuel and it was still doing it until one day the car just stopped...checked the coil and it wasn't even sparking.... but you probs are just running hell lean??

brisbanefastback Casual Dubber

36 posts · joined Jul 2007 · 17 Nov 2009, 8:39 pm

#747884

changing the coil made a huge difference, still not running right but recon that'll be down to the carbies needing a tune up.

Carter Seriously Crusin Dubber

104 posts · joined Oct 2008 · 18 Nov 2009, 7:24 am

#747943

flukey guess! 🙂 glad its running better. get onto those carbies but mate... if it's still backfiring it means it's running lean, which means your are slowly cooking your engine. get onto it asap 🙂