Since I updated to 2.7 my engine speed has been off. It changes, but it's about 15mph higher than actual. It's not the app as I tried downgrading it and it made no difference. Around the same time I saw my fuel pressure was 16-18 where it had been 12-14 before. I thought maybe there had been a bad connection and plugging the plug back in showed a more true pressure reading. Today I was taking my son to daycare and it showed 60psi as my fuel pressure. That scared me a little so while driving I shut the engine off for a sec then keyed it back on (manual trans) and it started running again. The fuel pressure didn't change but I noticed my vehicle speed was correct this time, and stayed correct the rest of the trip. After I got to work I shut off the truck and turned the key to run without starting, the fuel pressure showed as 30, then 44 when I turned it on. Just now an hour later I did the same thing it read 4 & 18psi. Any ideas why it would read like this?

Every time you push in the clutch your transmission is "slipping". In a manual case, it would be closer to clutch slipping than trans slipping, but it is still just a calculation. 

 

One thing I'm noticing is the speed sometimes jumps around. Like it'll  jump 3 to 10 miles an hour high and then come back down. This is with smooth study acceleration also

Edited April 29, 20187 yr by beren

This is most often caused by malfunctioning speed sensors. Does it jump on your dash gauge as well? or only the iQuad app? 

I am assuming that these jumps in speed aren't real and only what is reported. 

On 3/9/2018 at 9:04 AM, Mopar1973Man said:

Nope, the water hammer killed the fuel pressure sensor. You'll need a new fuel pressure sensor and relocate the sensor away from the VP44. This is one reason my fuel pressure sensor is mounted near the ABS module this gives over 6 feet of tube run away from the VP44 and pulses fade with distance. I'm sunning an ISSPro snubber and a needle valve which the needle valve has no purpose other to close the line if a leak occurs. 

 

So what did you do to move it, just get some ends and a length of fuel line? Do you think a small line would help to even out the pulses since it would stretch/absorb more? I just ordered a new sensor, gotta love eBay sales, I got 15% off :-)

12 minutes ago, beren said:

 

So what did you do to move it, just get some ends and a length of fuel line? Do you think a small line would help to even out the pulses since it would stretch/absorb more? I just ordered a new sensor, gotta love eBay sales, I got 15% off :-)