CM 870 ISX

[Chamberpains]

What are you using to get your exhaust temps? In tube or on tube? Factory dash gauge or aftermarket? Has it been verified to be accurate?

How are you getting your boost readings? Factory dash gauge, after market setup or or reading it from scanner or Insite?

If after market or factory dash gauges, have they been verified accurate? Insite only see's what the intake pressure sensor sends to the ECM.

[Kevroo]

The exhaust temp is just outside the turbo in the tube and does have a factory gauge in dash and same for the boost gauge it’s on the intake tube just before the air goes into the motor and is also factory. And as for reading correctly I have had the truck on several insites and they run all the tests and they come back as passed. I will mention that sometime ago the exhaust pressure sensor wiring was twisted and plugged into sensor and I noticed but can’t remember what colors were touching but they were bare and touching each other so I cut the wires and slid heat shrink over them and covered them back.

[Chamberpains]

Did you solder the sensor wires or use crimp on butt connectors to repair your wiring. If you used crimp on butt connectors, this could be some of your problem. Never never never use crimp connectors on sensor signal wires. This has proven to be a consistent problem with sensor wiring. Especially 5v signal wires. It causes irregular voltage spikes and drops.

Rawze knows better than me but 900° in pipe EGT's doesn't sound all bad when under load.

As far as the 30 psi boost, has anyone dyno'd or road tested under load to verify its only building 30 psi according to Insite? Have you verified your dash gauge is accurate? Dash gauges wear out and don't read accurate. Is the gauge getting its info from the ECM or is it a separate sensor with a pressure tube coming off it? If its a separate sensor with a pressure tube to the sensor or a seperate sensor you can hook a pressure regulator to shop air and send pressure directly to the gauge to verify its accuracy.

[Rawze]

just some reference...

Although there are a few smaller model engines that do,.. the ISX engine does not have a factory exhaust EGT sensor on it at all. It is calculated in the ECU and is well known to be inaccurate. If someone has a factory EGT gauge in your dash,.. either it is reading the calculated engine EGT (well known to be inaccurate sometimes), or maybe you have a EGT gauge with a probe the truck maker themselves has installed (highly doubtful)?,.. or it is after-market.

[Kevroo]

You are correct Rawze the probe does not have anything to do with the motor it’s just there, but as for Kenworth putting it in I have no clue but it’s in the dash in it own spot and when I gave Kenworth my Vin number they had the probe on the shelf for it for $300 but they said it was not doing anything in the ECM it just from probe to dash gauge so I didn’t purchase it. It is a Kenworth part, we are going to insite it on the road tomorrow. Now my question earlier where the fuel high pressure regulator is that screws into fuel rail is that sets in between the metering and timing actuators I’ve noticed if you look into the hole where it screws in, the back side where the regulator sets on the back side looks like a plate back there and on the top side of plate is broke off or supposed to be that way? I’m going to look at a 870 just like mine tomorrow, I know rawze you told me to sign up my Vin number somewhere but I can’t find where you told me that where was that again?

[Rawze]

(03-17-2019 )Kevroo Wrote:  ...
you told me to sign up my Vin number somewhere but I can’t find where you told me that where was that again?

quickserv.com

[Chamberpains]

Here's a video on the IFSM and fuel system on your engine.

https://youtu.be/HvvFElrc5ak

And part 2 for the rest of the fuel system.

https://youtu.be/_WeiDC6S8Lw