24 replies to this topic

[Chris74]

I have a strange problem with my innocenti rally car, it is a 1275 full race spec s engine, fully forged, fully balanced, high compression Full race head, 310 scatter cam, 45dcoe, aldon ignition sysyem, that's the engine. It will run like a rocket for a while (about 5 miles) then all of a sudden cylinders 1 and 4 will stop firing, if I take 1 and 4 plugs out they are wet and if I earth them they are still firing, I give them a quick wire brush and put them back in all is good for another 5 miles. I've changed leads, plugs, rotor arm, dizzy cap, gone back to points, changed jetting in carb, checked valve clearance and checked for air leaks but nothing is resolving the problem.
Any ideas?

[sonikk4]

Sounds like over fuelling. Has the car been jetted on a rolling road??

 

Has it got a fuel pressure regulator fitted??

[Sprocket]

Sounds like over fuelling. Has the car been jetted on a rolling road??

 

 

I concur

[Avtovaz]

Doubt it fuel mixture that way... Have you run it before ok?

 

I had a lada 2105 with a single 45 dcoe, with a standard 1500 engine it ran fine, even i drive it to hungary! But i had build a tuned 1600, and i had the same thing, two outer would not fire properly. Turned out with the extra breathing, the inner cylinder was robbing the outer of part of their fuel intake. I had to have a balance pipe put into the inlet manifold.

 

Also, with a scatter cam, if its not timed in 100% correctly, itll not run right, its not alike a normal cam, its a cam tuned for 4x1 cylinder engines, that is what vizard said. So check the cam timing.

 

 

 

If you cant sort it, see if you can talk to vince mosely down your way and see what he says...

 

hth.

Edited by Avtovaz, 24 June 2017 - 10:07 PM.

[nicklouse]

the Weber does over fuel the outer cylinders. depending on the inlet manifold.

[Chris74]

The car has been running this set up for years, not one problem until one day it decided it wasnt playing anymore.

[Chris74]

Exhaust and inlet manifolds are matched to head ports.

[Chris74]

Also all timing is done with dti via vernier pulley so its bang on.

[sonikk4]

My question still stands, has it been on a rolling road trip especially recently.

Webers do go out of tune and will need periodic check ups. I had twin 45's on my RS2000 and one plug would always foul. New plugs, different types, trip to the rolling road etc. What I had not done which I should have was fit an electric pump with a Facet fuel pressure regulator. My bad then but I had then reverted back to a 32/36DGAV more for economy as it became my daily for a while.

I still took my car to the rolling road once a year just to make sure all was good. Overkill maybe but at least I knew then there were no underlying issues with engine.

It was a heavily modified 2.1 Pinto.

[Chris74]

Got a facet pump runing through filter king regulator at 5 psi. Not been to a rolling road, nothing has changed though, good one day then bad the next.

[Chris74]

May have to take it to moselys.

[Earwax]

If original metal float bowl check the tangs that set the bowl height... where they sit onto the float...  I have seen farting liking symptoms because this joint is loose ( needs soldering or similar) the bouncing of the bowl over time can do something to fuel pick up ( either aerates it or overfuels it...)  i would very carefully check fuel bowl height at same time... hope you sort it,,,,, irritating

[Chris74]

Yeah checked float level and changed floats.
It is really irritating.
Thanks for your help anyway guys.

[nicklouse]

Got a facet pump runing through filter king regulator at 5 psi. Not been to a rolling road, nothing has changed though, good one day then bad the next.

5 is a tad high. i ran/run less.

[carbon]

I have a strange problem with my innocenti rally car, it is a 1275 full race spec s engine, fully forged, fully balanced, high compression Full race head, 310 scatter cam, 45dcoe, aldon ignition sysyem, that's the engine. It will run like a rocket for a while (about 5 miles) then all of a sudden cylinders 1 and 4 will stop firing, if I take 1 and 4 plugs out they are wet and if I earth them they are still firing, I give them a quick wire brush and put them back in all is good for another 5 miles. I've changed leads, plugs, rotor arm, dizzy cap, gone back to points, changed jetting in carb, checked valve clearance and checked for air leaks but nothing is resolving the problem.
Any ideas?

Chris, looks like you have not yet changed the coil. How hot does the coil get?

Edited by carbon, 25 June 2017 - 01:32 PM.