Motor diagnosis help Options

[rtalich]

I built a type IV Torquer kit complete with SDS EFI over a year ago. It’s been running awesome ever since. In fact, once I got the tuning figured out it kept getting better and better. Just recently, about a month ago now, it’s like someone flipped a switch and it started running terrible. All of a sudden, it started running very lean and therefore getting hot. I traced the problem down to be an inadequate fuel filtration system, which caused my injectors to clog. I resolved that problem thinking that was the sole source but came to realize it was not. The only thing that I can think it could be is the timing somehow got messed up. I think I’ve checked everything I could to rule out something mechanical. My leakdown numbers are #1 – 18%, #2 – 19%, #3 – 15% and #4 - 16%. I know these aren't the best numbers but not sure if they could be causing the problems I'm seeing. Please let me know if I'm wrong...... Compression numbers on all cylinders were measured to be 165-170psi. I checked timing and somehow is off by about 10* and can’t be corrected with the SDS programmer. The only way I can think of how the timing could’ve gotten messed up to produce these results is if the pulley shifted on the crank or the sensor moved somehow. All these ‘look’ OK. I’d need to remove the motor in order to thoroughly check to be sure. Here are a couple of videos to help solve this problem.

http://www.youtube.com/watch?v=-ymZQDYepMY

http://www.youtube.com/watch?v=jtN7EeyxFek

I just would like some confirmation that I’m on the right track before going thru the hassle of removing the motor only to find that it wasn’t the issue.

Thanks,
Rob

[orange914]

2 things i noticed
1] backfiring
2] disconecting #1 injector didn't pull down the motor much.

are you sure you injectors are flowing equal and not leaking? the backfire popping and the way it cleared up with the r.p.m.s coming up indicates it may be rich at idle (flooding abit). if the injectors are leaking from the crap that got thru before...??

just a thought

mike

[rtalich]

2 things i noticed
1] backfiring
2] disconecting #1 injector didn't pull down the motor much.

are you sure you injectors are flowing equal and not leaking? the backfire popping and the way it cleared up with the r.p.m.s coming up indicates it may be rich at idle (flooding abit). if the injectors are leaking from the crap that got thru before...??

just a thought

mike

Thanks for the reply! Its kind of hard to tell from the video but they all seem to behave equally when pulling the injector plugs. I had all the injectors cleaned, filters replaced, flow checked.... It seems to idle perfectly, AFR is right at 13. Its when I start reving it is when it backfires. When I do rev it, the only way I can keep it running without backfiring is by pumping the throttle, giving it more gas.

[DNHunt]

Rob

How about the sensors on the FI. Check to see if they are functioning as expected. MAP sensor failure or MAT sensor failure both could cause a lean mixture and should be apparent on the first 4 screens on the programmer. If you want we can swap my sensors out for a trial.

If not sensors I would still wonder about fuel delivery. I know you got the injectors cleaned but did you get a report on flow rate? Is the fuel pressure staying high enough? Could junk have plugged the fuel regulator?

I would run a cold leakdown with the rockers backed all the way off. Take the valve adjustment variable out of the equation.

I kind of question your leakdown #'s. With that high of compression I would expect that the leakdown figures would be lower. Did you notice where it was hissing?. I like to use a piece of vacuum hose as a cheap stethoscope to stick in the oil filler and intakes. Exhaust you just have to get down on your knees and listen.

Dave

[rtalich]

Rob

How about the sensors on the FI. Check to see if they are functioning as expected. MAP sensor failure or MAT sensor failure both could cause a lean mixture and should be apparent on the first 4 screens on the programmer. If you want we can swap my sensors out for a trial.

If not sensors I would still wonder about fuel delivery. I know you got the injectors cleaned but did you get a report on flow rate? Is the fuel pressure staying high enough? Could junk have plugged the fuel regulator?

I would run a cold leakdown with the rockers backed all the way off. Take the valve adjustment variable out of the equation.

I kind of question your leakdown #'s. With that high of compression I would expect that the leakdown figures would be lower. Did you notice where it was hissing?. I like to use a piece of vacuum hose as a cheap stethoscope to stick in the oil filler and intakes. Exhaust you just have to get down on your knees and listen.

Dave

I would love to swap anything I can to try and rule things out of the equation. I'll take and try anything you'd let me borrow if I could. I did not get any sort of report on the flow rates for the injectors but I will find out. The fuel pressure is steady on the gauge when reving the motor. All the hissing noise, as far as I can tell, was comming from the oil filler, nothing from the intakes or exhaust could be heard.

I'll give you a call later today. We are planning to be down your way later this afternoon/evening.

Thanks,
Rob

[messix]

tps?

[DNHunt]

Rob

I'll be around until about 5.

Troy,

The TPS doesn't do much but give acceleration enrichment

[messix]

Rob

I'll be around until about 5.

Troy,

The TPS doesn't do much but give acceleration enrichment

never mind