Unusual timing problem

Lenny · February 4, 2011

Trooper started running real poor. Would run real rich until I gave it gas then it would flood indicated by the oxygen sensor jumping to very lean, 20:1. When it floods, it stops burning the fuel so the oxygen is left over, but not because it is lean. Wouldn't hardly go. could idle but had no power what so ever. Figured I messed up my tune so played with it for a few days. I could get it to rum better but never good. Then I thought I damaged the engine so I checked compression, All 4 cylinders were at 135+-1 pound, not a problem. Remember I have lowered my compression for the supercharger so this was just right. Surprised they were so identical. Then rechecked timing with a light, perfect. Checked for input from all the sensors, no problem. Pulled the head cover to check if the timing belt slipped a cog, nope. Made sure all the valves had the proper clearance, fine. Checked my fuel pump for proper pressure and volume, OK. Scratched my head a lot and went back and read the Megasquirt manuals for about the 10th time. Then I went back to square one and set number 1 cylinder to top dead center to start over rechecking valve position and timing. Now timing showed being off by 30 degrees advanced. But the timing light showed it right on. Then it dawned on me, the 36-1 Edis timing wheel has moved. But how, it's weld on to the supercharger drive pulley which is tightly pressed onto the alternator stock drive pully. The stock drive pulley is the engines harmonic balancer so it has a rubber cushion molded in between the inner part connected to the crank and the outer drive pulley part. The outer portion was slowly slipping on the inner part gradually changing my timing but because the timing, the computer sees, is based on the placement of the missing tooth, it showed and checked correct. I omitted the rubber and welded it solid in the correct relationship to the engine and it all runs great now. That took about a week and was hard to find but finally it’s corrected.

Lenny

rocmoc · February 4, 2011

Ah Lenny, that is from running those high RPMs with your Turbo! Slow down boy, LOL.

rocmoc n AZ/Mexico

Kinarfi · February 4, 2011

Did you take any photos, is the 36-1 Edis timing wheel the wheel that drives the alternator and water pump or is it something to do with your super charger and something the rest of us don't need to worry about.

Is it in this picture? Possibly, is it on the left side? What timing is it effecting, spark timing, or injection timing and where is the timing signal coming from? I'm assuming the MegSquirt has it's own timing signal coming from the 36-1 Edis timing wheel. I'll ask more later.

Kinarfi

Lenny · February 5, 2011

Did you take any photos, is the 36-1 Edis timing wheel the wheel that drives the alternator and water pump or is it something to do with your super charger and something the rest of us don't need to worry about.

Is it in this picture? Possibly, is it on the left side? What timing is it effecting, spark timing, or injection timing and where is the timing signal coming from? I'm assuming the MegSquirt has it's own timing signal coming from the 36-1 Edis timing wheel. I'll ask more later.

Kinarfi

It's nothing you guys need to worry about. I mention it only because you can sort of see the process I went through to find a problem. The Edis 36-1 timing wheel is something I added to provide a timing signal for the megasquirt. What caused the problem has got to be about as rare as it gets. Sorry Rocmoc, don't use a lot of RPMs anymore, but I still wondered for a while if I damaged my engine. I have my RPM limit set at 5500 in the computer. Torque is good.

Lenny

CrawlnT2 · February 7, 2011

It's nothing you guys need to worry about. I mention it only because you can sort of see the process I went through to find a problem. The Edis 36-1 timing wheel is something I added to provide a timing signal for the megasquirt. What caused the problem has got to be about as rare as it gets. Sorry Rocmoc, don't use a lot of RPMs anymore, but I still wondered for a while if I damaged my engine. I have my RPM limit set at 5500 in the computer. Torque is good.

Lenny

What computer are you running?