1998 Sig600/CM570 Multiple Issues

[Rawze]

sounds to me like something went wrong during the rebuild? or that some idiot put the wrong program in the ecm?

Perhaps the wrong overhaul kit? - Maybe a slipped cam? ... who knows.

Also the engine overheating is a huge red flag. That is not normal at all. - Anyone bother to change the thermostat and that brass ring in the bottom of the thermostat housing?. - Bigger radiators is not the answer... that will only contribute towards masking the real problems, allowing for something to fail without warning later on.

When the power falls off, has anyone bothered to find out what the engine state and other data is in the ecm while going down the roads to see why the power is not at 100% output?. When is the last time the major engine sensors have been changed out?. When is the last time the overhead valves were adjusted?. When is the last time somone did an injector leak test on it? (ref: https://youtu.be/Wu_WN8BA-LA ).



* Do an overhead valve adjustment on it followed by an injector leak test. Also pressurize the entire engine and not just the CAC unit?. > I.E.> Plating off the intake port of turbo and exhaust port of of turbo) and pressurizing the whole engine up? ... making sure there are no boost or other air-related leaks.


Also during the rebuild ... was a brand new OEM-only head used? -- or something else, like some re-machined garbage or old head re-worked and slapped back on? - This can be some of the problems too. - Might want to pull all the rocker shafts off and pressurize the intake manifold and exhaust manifold and see if there are any valves letting air past them causing compression loss.


Does it have the correct OEM turbo on it still? - or some dick#head replace it with something else?

Does it have all original certified OEM parts + were all new or PX? -- in it or some idiot put the wrong injector part#'s or reman from a shop somewhere, etc... or other garbage in it?

What about the diaphrams in the back of the IFSM? -- and the solenoids, etc? .. there is a lot to the ISX that a lot of people overlook and neglect then wonder why they have all sorts of issues.

Maybe re-wedge the cams to ensure someone did not use the wrong wedge kit offsets or the cams have not slipped due to some idiot not following all procedures + using proper amounts of 609 on the tapers when the gear train was put back together.


- and how old is the engine wiring harness?-- When is the last time the entire harness was replaced?

just some thoughts any ways.


As far as the fuel return lines to the tanks,.. the splitter valve is the first thing you should have looked at. Next is any restriction in the bleeder tubes at the top of the tanks .. or any leaky lines. This is not an engine issue, this is a fuel line return or pickup-tubing issue.