Redneck Mech

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K-bo, I've checked voltage supply to the ECU and it's 12vdc-12.38vdc. I also checked the 5vdc supply to the TPS sensor, ECT sensor, and manifold pressure/temperature sensor. They are all 5vdc-5.02vdc. I literally checked for opens, shorts, and grounds for all wires between all sensors and ECU connector and didn't find anything abnormal.

So far the only code we've seen is a 118. I did verify the 5 vdc supply and ground to all sensors. I also verified the .50-.60 vdc return from the TPS at closed throttle. This check was made at the ECU connector. The return rises smoothly with the actuation of the throttle, up to about 4.4vdc-4.6vdc. As far as the 118 code, it's a new ECT sensor and I've verified the return signal back to the ECU jack. This signal does vary with the engine coolant temp. We have not done a hard reset of the new ECU.

Okay, I could use some help over here. I'm helping my brother with a Massimo Alligator 700. We've replaced virtual everything and can't get it to run. It all started back in November. I was making the rounds in my deer lease and after about half hour of running it cut out and died. It started back up, ran fine for several hundred yards, cut out and died again. This repeated all the way back to the truck. Came back a few days later and started troubleshooting. I suspected water in the fuel because the machine had been stored outside for several weeks. Fuel was fine. Symptom got steadily worse until it won't even idle. I won't go into the incredibly long story of everything we've tried just yet but here's my immediate question. What could cause this thing to idle good, for as long as you want it to, but only with the new TPS unplugged? The fuel pressure shows to be about 38 lbs, stable, coming from the new fuel pump to the new injector. If I restrict the return line to increase fuel pressure to 65lbs or more, all symptoms go away and it runs like banshee!

https://www.ebay.com/itm/201262591448?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=Jb7c4YGJRFW&sssrc=2349624&ssuid=6zHtbBAeSTO&var=&widget_ver=artemis&media=COPY

Okay, so I'm in the process of rebuilding the top end of this machine and I can't find any timing marks on the cam. No notch, no dot, no painted tooth, nothing. Does anyone know what it's supposed to look like?

Okay I'm looking for some technical help. I bought a new Throttle Position Sensor for my Massimo MSU 500 and I'd like to know the correct procedure for setting it up. I've set one on my Fox bodied Mustang several years ago but I can't remember how, or if it would even be the same. Haven't had any luck finding a YouTube video on it. Any help would be greatly appreciated. Thanks!

Well now, that's a good thought. Tomorrow night when I get home I'll redo my compression test and this time I'll add a little oil. If the compression improves, it's rings, if not, it's valves. I new that just didn't think to do it. Thanks!

No, it wouldn't, but I don't think the low compression would cause the spark plug to soot up. That's a definite sign of running too rich. If one of the sensors is sending an erroneous signal to the ECM it could cause it to run rich.

I'm starting to wonder if one of my sensors is bad. The only new one on it is the O2. It's got a new injector so I'm assuming it's not causing the rich condition.

Doesn't smoke at all. Just very weak.

Update: I just ran a wide open throttle compression check and it's 135! According to the stats that I dug up it's supposed to be between 163 and 210. So, that's not good. Also when I removed the spark plug it was chalky black with soot. So I've got something else going on, I'm not sure what yet. Grrrr!

Thanks Alex. I was going to post it here to begin with but there doesn't seem to be a lot of activity in this area.

Yeah well, I figured for $50 it'd be worth a shot. I'll do some digging around on this forum and see what I can find. Thanks!

Here's a "before" pic