Fuel pump and gauges cutting out?

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Blenderhead

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Ok, so my car did this for the second time this morning. I started it up to go to work, and I got about half a mile down the road, and it completely cut out. I still had the speedo, but the engine shut down, tach and temp gauges were off. The car started slowing down, and then it started back up, but the tach and temp gauges still wouldn't come up. I drove it to work, shut it down, and it started right back up with no problems and the gauges came back when it was restarted. I just checked the codes on it and it has P1234 Fuel pump diagnostic module signal lost and P1238 Fuel pump diagnostic module offline. I have no codes about the coolant temp and tach though. Has anyone ever had anything like this happen before? The problem is intermittent, so checking all the voltages at the pump and module etc won't help me until I'm permanently stuck on the side of the road. It seems it only happens within a few minutes of starting the car in the morning. Yesterday morning it also bucked a little bit, almost at the exact same place, but the gauges didn't cut out and it was for less than a second, so I didn't think too much of it. Today it was out for probably 10 seconds or so before it would come back on. Any ideas?
 
Im too tired to think much :) lol But my first thought is a battery connection/ground issue...
 
Check the connection of the back of the power distribution panel "the fuse box under the hood".
On the back of it is a positive connection/lug that sometimes "does stupid stuff".

You might start the car, and wiggle that box and see if the car does anything stupid.
 
Hmmm.... considering that your car is T45 swapped I would be curious if it was realted to that... only reason I bring it up is that your car is a few deviations away from a normal Mark VIII....

It does sound like some kind of ground issue though...
 
When everything cut out like that I initially thought it was a problem with the PCM losing power or ground or something like that, since I did have to extend the harness for it, but then when I checked the codes and found those 2 for the fuel pump module, and no other engine codes, it got me thinking that it might be something else. Probably tomorrow I'll go over the whole wiring diagram for that fuel pump module and see if I can find anything. I really hate intermittent problems!
 
It started doing this all the time now. On the way home tonight, the engine cut out. On the info center I get "check traction control" and "fuel flow data error". The tach was cutting in and out, and the temp gauge would drop to all the way cold for a while, then spike up to all the way hot. If I took it out of gear, the car would restart perfectly fine, and it will idle fine, and rev up fine out of gear. As soon as I put it into gear though, it dies. I check the codes and here is the list
P0708 Trans range sensor (disregard this, as the car has a T45)
P1234 Fuel pump driver module offline
P1132 H02S11 indicates rich
U1009 SCP Data Fault Engine Torque
U1027 SCP Data Fault Engine RPM
U1059 SCP Data Fault Trans PRND (again, probably disregard)

I also noticed in the datastream that 02 sensor 1/1 is reading a constant 0v. Maybe that came unplugged or something, I'll check when I get the car up on a lift some time this week.

I wish I could figure out what is going on with the temp gauge, but there is absolutely no wiring diagram for it! All it says on the diagram is "instrument cluster, solid state" and it has a box with an input from the PCM. Maybe if I could see what could cause the temp to go all over the place like that, then I might have a better idea where my problem could be, but as it is now I have no idea what is causing this, and no way to test it because it only happens when the car is driving down the road, never when it is sitting still.

Anyway, hopefully someone will have some ideas as to what this could be. I'm getting entirely too aggrivated and pulling my hair out over this. I hate when I can't test something and I'm stuck just guessing at what the problem might be.
 
VSS is plugged in. It is off because I still have the gear for 3.27s in there and I have the 3.73s in now, but it is plugged in.

I was going through all the diagrams, and I found a few grounds that might be causing it, G103, G205, and G302. I'm leaning towards G205 because it is where all the ECM grounds go to, and it says on alldata that ground is "behind instrument panel on master cylinder bracket, and since that is where my clutch pedal and all my wiring is, I might have relocated that and it might not be making good contact anymore. Just incase though, does anyone have a better description of where G103 is? Alldata just says "lower left front corner of engine compartment", which isn't as specific as I would like it to be.
 
I would unplug the VSS.... see if there is a change, maybe if the car Thinks it is sitting still it will work....
 
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