Help - RSR Clone Engine Not Firing

tom1394racing · 05-07-2015, 10:45 AM

I need some suggestions from the collective experts here...

My RSR clone engine is a 3.0 twin plug with MSD, Bosch dizzy, 10.5 CR, headers and 46 mm PMO's. The engine has performed flawlessly for over 10 years with only normal maintenance.

I took the car out for drive with the wife this past Sunday and all was good. Car running perfectly as usual. I parked it, we went for a walk and came back about 2 hours later. The car started very roughly and could not be driven. It felt like it was running on one or two cylinders and there was a strong smell of gasoline. I had the car flat bedded home.

The next day I tried starting it in the garage. There were a couple of backfires but no start. I went back behind the car to find that fuel had been spewing from the header outlets. Lucky no fire.

I checked the sight glass on the PMO's and one bowl on each side of the engine did not show a bubble. I drained the fuel from the bowls, replaced the drain plugs and ran the fuel pump to observe the bowls filling. The same two bowls filled past the top of the sight glass. So I figure needle valves stuck open. This could make sense as I was running low on fuel and maybe some contaminants made their way into the valves. So I removed the carb tops and cleaned the needle valves out with carb cleaner. I reinstalled the carb tops and checked the bowl filling to find that all bowls filled to the mid level of the sight glass. Problem solved I figure.

Not so. While the raw fuel spewing is gone, the car will not start and only pops and sputters. So I think, maybe blocked idle jets. After all, whatever got into the needle valves could be blocking the idle jets. Running the car too low on fuel in the past has resulted in partially blocked idle jets. So I remove them and blow them out with compressed air.

No difference after cleaning the idle jets. I am thinking maybe something else in the carbs may be contaminated. Anyone have some suggestions where to turn next?

jpnovak · 05-07-2015, 01:25 PM

Tom,

Have you checked the ignition? Do you have spark at the plugs? MSDs have been known to go out but Its not likely they would both have issues at the same time.

Have you pulled the plugs and cleaned them? They may be fouled. This would probably explain it running on 2 cylinders.

Just cleaning the jets may not be enough. You may have to pull the carbs and clean the float bowls and all the passageways.

You might also consider to clean the fuel filter.

tom1394racing · 05-07-2015, 01:44 PM

Jamie

Thanks for replying. I did remove, clean and check the top plugs to make sure I had spark. I also checked compression while I had the plugs out. No problems there. I am going to try some starting fluid into the airhorns while my wife cranks to confirm adequate spark. I figure if it fires, with starting fluid, the problem is in the carbs.

Any additional ideas are welcome.

BURN-BROS · 05-07-2015, 06:20 PM

Hi Tom, Sorry for your woes.

Do a quick leak down and compression test. Make sure there was not a hydraulic situation.

fanaudical · fanaudical's Garage

Sunk floats?

tom1394racing · 05-08-2015, 04:08 PM

Well still no joy today.

This morning I changed the top plugs out and disconnected the bottom plugs at the distributor. I figure the top plugs should be enough to fire the engine and removing the bottom plugs takes away one variable. I removed the air cleaners and sprayed starting fluid into the air horns while my wife tried to start the car. No start . Only pops and flame out the exhaust.

So I figure I've narrowed the problem to the ignition.

So, I figure that I created another problem in my efforts to fix the original stuck needle valve issue. The only thing I did to the ignition was to remove the plugs, plug wires, cap and rotor. So I figure maybe I disturbed something in the ignition wiring. I removed the top plug wires and checked them for resistance, I know from previous experience that the combined resistance of the wire and Beru connector should be around 5-8 K-Ohms. I found 3 of the 6 to be shorted or in the M-ohm range. I think the connectors at the distributor were not robust enough. so I replaced the wiring and connectors in all leads until I had 5-7 k-ohms in all leads. So I cross my fingers, install all the refurbished wiring and try to start the car. No difference still a couple of spurts out of the exhaust but no fire.

Ideas??

jbell959 · 05-08-2015, 04:15 PM

Green distributor wire?

stownsen914 · 05-10-2015, 06:08 AM

Quote:

Originally Posted by jbell959

Green distributor wire?

Tom - try squirting some starting fluid into your air filters on both sides, and try to start it. It will only fire fora second or two, but it will help distinguish between ignition problem vs. fuel problem. It would be an odd coincidence to have the fuel issue you mentioned (unless it simply flooded from long cranking or something) and not be part of the problem.

Any chance of water in the gas?

Scott

tom1394racing · 05-11-2015, 03:28 AM

I tried the starting fluid directly down the air horns while my wife cranked. No start. Only a few coughs and some flame out the headers. This has me focused on the ignition.

tom1394racing · 05-16-2015, 12:24 PM

Problem solved. I checked the timing and it was advanced at 35 deg BTDC while cranking. I removed the distributor and reset the static timing to about 10 deg. It fired right up and ran beautifully.

I will be changing out all (3) fuel filters as part of the spring tuneup this week.

Thanks for all the input.

Walt Fricke · 05-16-2015, 11:08 PM

Would that all problems were so easily solved once you looked in the right place!

tom1394racing · 05-17-2015, 01:22 AM

What is still not clear to me is what caused the timing to change so drastically.

The original problem was a stuck open needle valve. I misdiagnosed it and swapped out the cap and rotor before finding and fixing the needle valve. When the car still would not fire even with starter fluid, I started looking at the ignition and found the static timing to be advanced to 35 deg. I never moved the distributor so how could the timing change?

Jcslocum · 05-17-2015, 03:32 AM

Mis-wiring the cap???

tom1394racing · 05-17-2015, 03:55 AM

The timing light was clearly using the signal from # 1 plug when I found the advance problem.

Walt Fricke · 05-18-2015, 07:10 PM

My thought was same as Josh's: when you put on the new cap, you got the wires installed wrong. Easy enough to do.

Then you found the float issue. Then it still wouldn't start, but the #1 was faithfully firing its plug, so the timing light showed it firing, and that it was 35 engine degrees off. If you'd just moved the wires around (the right direction, whatever that would be) instead of resetting the distributor, would it have started?

tom1394racing · 05-19-2015, 02:16 AM

Quote:

Originally Posted by Walt Fricke

My thought was same as Josh's: when you put on the new cap, you got the wires installed wrong. Easy enough to do.

Then you found the float issue. Then it still wouldn't start, but the #1 was faithfully firing its plug, so the timing light showed it firing, and that it was 35 engine degrees off. If you'd just moved the wires around (the right direction, whatever that would be) instead of resetting the distributor, would it have started?

I agree with you both. It had to be an issue with brain fade on the plug wires.