Quit running not starting

LMWatBullRun · **Posted:** Sun Apr 02, 2017 4:46 pm

flash7210 wrote:

Next test.
With the engine idling and in park, watch Torque while wiggling the wire connector at the fuel quantity solenoid. If you see a similar drop in fuel pressure or the engine sputters and stumbles, replace the connector for the FQS.
Then, do the same test at the fuel pressure sensor.
And again at the fuel rail pressure solenoid.

So, I just did that at the fuel rail pressure solenoid, no joy.

I've already replaced both the fuel pressure sensor and the connector for that.

How in the world do you get at the FQS while the vehicle is running? No, wait, how do you get at the FQS without removing the alternator?

flash7210 · **Posted:** Sun Apr 02, 2017 5:15 pm

LMWatBullRun wrote:

flash7210 wrote:

Next test.
With the engine idling and in park, watch Torque while wiggling the wire connector at the fuel quantity solenoid. If you see a similar drop in fuel pressure or the engine sputters and stumbles, replace the connector for the FQS.
Then, do the same test at the fuel pressure sensor.
And again at the fuel rail pressure solenoid.

So, I just did that at the fuel rail pressure solenoid, no joy.

I've already replaced both the fuel pressure sensor and the connector for that.

How in the world do you get at the FQS while the vehicle is running? No, wait, how do you get at the FQS without removing the alternator?

Idk.
Maybe because I have the sasquatch intake elbow?
I just reach down and grab it. There is not much un the way.

LMWatBullRun · **Posted:** Sun Apr 02, 2017 5:28 pm

OK. messed around with the RP solenoid wiring and rapped it. Libby didn't blink,

Ran this thing for 15 miles up and around. Most of those were in limp mode, and unless I pressed hard on the accellerator, it would not stop running; if I stayed off the throttle it continues to run. Fuel pressure varied between about 4400 pounds and 19,000 pounds, depending on RPM and load. The only component I have not changed is the rail pressure solenoid; I may change that, the connector and the FQs connector too.

What causes limp mode? Fuel leak will do it, but what else? Am I looking in the wrong place?

flash7210 · **Posted:** Sun Apr 02, 2017 5:46 pm

What causes limp mode?

When the ECM detects component fault or a sensor value that is out of range.
Which could be:
1. An actual detected fault
2. A bad sensor
3. A wiring problem (open circuit)

rankom · **Posted:** Sun Apr 02, 2017 6:32 pm

in my case when i have a problem diagnosing fuel system , i go to BOSCH , guys , yes i been on shop floor so its easier to get to those guys LOL . but it is better to find them , then do guess work for 2 months and face same problem , again we do have this vehicle as a hobby but man this shouldn't take this amout of time ,

rankom · **Posted:** Tue Apr 04, 2017 8:42 pm

this is just a thought in this weird problem with limp mode , if i remember correctly you replaced injector #2 with your spare unit and engine started , I'm not sure if it would make difference if you program this calibration code into ECM , i heard some people experience this problem with sprinter van engine when injector was replaced , but trim code was not programmed into ECM, but again i have one of my injectors in my jeep that i didn't program calibration code yet ,and it runs normally , so reason I'm saying this , in your case you need to cover all the basics , or like i said it could be someting like that , and ECM is just shutting your fuel ?

Quit running not starting

Who is online