V2Rocket

are you sure the throttle plate is opening fully?

WPO

This hasn't been checked. Would this cause such problems with the ignition?

V2Rocket

DME calculates engine "load" using throttle position input (idle/WOT or a part-throttle value interpreted by the KLR), and AFM data with some adjustments from other sensors.

using load + rpm it figures appropriate spark and fuel...

you said the TPS values didnt match clark's specs...what are you seeing?

WPO

http://www.clarks-garage.com/pdf-manual/ign-03.pdf

Here it's said that throttle closed the value should be between 320 and 670 and we saw 570 so that's OK and throttle open 2700 - 4700 ohms and we saw infinity starting when the throttle was around 80% or so open. Before that the values didn't go to 2700 ohms.

lfisher

Are you sure the timing is part of your problem?

Under heavy load or WOT there will be very little if any timing advance with RPM.

It is only under light or no-load situations the timing advances with increased RPM.

WPO

Timing is so much retarded that the header glows bright red and the car doesn't make any power. This is exactly like the "safe mode" (or what's the right term?) as per the WSM.

Now what causes this is the interesting question. Somehow the KLR gets an incorrect reading from a sensor or its missing some info? I'll try the right way to bypass kLR and then let's see if it makes power.

Tom M'Guinn

I wouldn't floor it with the KLR bypassed. It controls boost and triggers the WOT maps, etc.

WPO

Thanks. That's a good point to keep in mind. We'll see if it boosts though without flooring it though. Interesting times ahead

Perry 951

Have you verified the pressure line to the KLR isn't leaking or otherwise damaged? If the KLR isn't seeing boost yet the DME is reporting RPM/TPS/AFM values that would indicate boost should be present, I can see how it would send it into fault. Blink codes should tell you this tho.

The pressure transducer could be faulty as well but I think you said you tried another KLR.

WPO

Pressure line was tested. It seems I forgot to add that to the original list as well.

I'll check the blink codes once my buddy comes back from a small trip.

Tom M'Guinn

Glowing headers could be caused by lots of things. I think the point IFisher was making was a good one. If you look at the WOT maps, the timing only changes two or three degrees in the boost range, barely enough to see with a timing light with a motor rumbling at full tilt. I'd check the blink codes for sure, but keep an open mind about the cause. Is it lean? Is the cam belt aligned? Is the exhaust clogged? Is the FQS pulling timing? Are the exhaust valves sealing? It does 'sound' like something is putting it in limp mode (knock sensor, KLR error, etc.) but it doesn't really sound like the "ignition advance doesn't change" -- which would be very hard to explain. You say it advances at lighter loads, but not on boost loads, but that's essentially what you'd expect to see based on the maps.

WPO

Very good points!

I'm told that the belt alignment has been checked but then again I haven't seen this myself. Would be good to check this ourselves to rule out the possibility of belt misalignment.

Exhaust is not gloggled: crossover pipe is not collapsed, cat is not melted / stuck and muffler is good.

No idea on exhaust valves sealing. I'll put this on to-do list also.

How do I check if FQS is pulling timing? I found a site where the FQS can be adjusted - am I on the right track? So should I check the position of the switch?

I'll read the blink codes and lets see what story they will tell us.

Again: thanks for the patience and support!

lfisher

The FQS switch will only affect the timing by a few degrees.

Under heavy load or Wide Open Throttle if the timing is too advanced you will get preignition or knocking because the abundance of fuel air mix in the cylinders will promote a faster flame front. That is why under heavy load you shouldl see very little or no timing advance.

In carbureted gasoline aircraft the Exhaust Gas Temperature gauge is important to monitor. If the fuel mixture becomes lean because of altitude changes the exhaust gas temp goes up and the pilot must manually enrich the air/fuel mixture to keep it under control.

If your motor is running lean you will get high exhaust gas temperatures.

lfisher

Have you checked for a vacuum leak between the AFM and turbo?

WPO

No this hasn't been checked as per my information. I'll add this into the to-do list.

Is the FQS only way to enrichen the mix? In case the car runs lean? Based on what I know the car is not running lean though - however, if it is what can cause this and how to adjust the mix? DME controls everything, right?

Can a bad lambda sensor cause this?