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TST Issues

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I've talked this over with a tech at TST. However, I'm curious as if anyone else had this issue and how it was resolved.



Symtoms:



Rail pressure DROPS like a rock. Even on moddest settings (4hp,tq4, 2/2, hp9,tq2or1)



I do her some injector rattle when I'm backing off the throttle lightly.



The majority of this seems to be on the low end, under 1800rpm (when HP settings take over?). On the upper band of the RPM range, 2500rpm+ she pulls really well, not has hard at the HotJuice (when on hp9,tq1).



I've pulled the rail harness. Same result. Added Smarty on software 8, same deal!



I can't get the TST box to smoke much more then a hazz in the daylight! :). Can't get the Smarty to smoke either!



I've even put in the by-pass plug and it does the same things!.



Could be either a bad Rail Pressure relief valve or harness



I don't think it's a relief valve cuz this happens LOW in the RPM's and the rail gauge never makes it much past 17K and will pull down to 7-10K (and the truck starts missing at this point).



On the higher RPM's runs, the rail does hold about 20K-21K,



I'll verify the harness issue MAYBE tonight when I get home. What sucks is them 2 plugs there at the Crank and Cam sensors to get un-plugged :)



No other codes other then the 0088 that I got (high rail pressure) once.



TST is unfortunately out of harnesses for the 04. 5. :(
 
To test your rail relief valve, or to rule it out, remove the banjo bolt out of the top of the valve and look down into the valve, it should be dry.



Now start your truck, rev it if you want, to raise rail pressure, if it leaks, it's shot, kaput!



Mine sprayed fuel all over the underside of my hood, so you may want some rags handy.



Capped mine with a solid bolt and urethane washer.



Jess



Plugged fuel filter?
 
To test your rail relief valve, or to rule it out, remove the banjo bolt out of the top of the valve and look down into the valve, it should be dry.

Now start your truck, rev it if you want, to raise rail pressure, if it leaks, it's shot, kaput!

Mine sprayed fuel all over the underside of my hood, so you may want some rags handy.

Capped mine with a solid bolt and urethane washer.

Jess

Plugged fuel filter?

See, the rail was fine. Performance was fine. I plug in the TST box. Settings REALLY LOW. like 1/1 or something. just something you can feel a little and took it for it's first drive and it ran like crap. I don't think the rail is broke cuz I never really stressed it at first. However, I've never had a broken valve before, so I'm not 100% sure what it feels like. Logically, it could be a busted valve. :) Also Logically the harness could be messing with things as well.

We'll see. I will be checking both (harness and valve) tonight if at all possible.

what did you do about capping off return line? something about a bolt and a few washers?

Fuel filters are fine. Pressure up to the CP3 never drops below 12. I'm going to be putting a 30PSI spring in place this weekend.

I might step early and try to maybe pull that crank and cam sensor wires in the parking lot. if I can get my fingers in there.
 
The rail relief valve does not really "break", it is spring loaded to release around 26k psi... I believe. Once it has activated the spring becomes weak, and each time this happens it gets weaker and weaker.



If it runs fine without the TST, then you have probably solved your own problem. I am not sure which TST you have, but mine is an early R37 and it does not add pressure.



Might have to send it in for repairs, however I posted yesterday under the title "TST". Looks like they are moving, or selling out, so not sure where to send it to!



Oh, I see your TST in your sig.



Are you stacking with your Smarty? I cannot run any TQ settings on my TST, with any, any Smarty Downloads, runs like crap, misses, bursts, whatever. HP settings only on the TST with a Smarty on my truck, too much fueling down low otherwise, runs out of fuel.



Could also be your FCA.
 
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The rail relief valve does not really "break", it is spring loaded to release around 26k psi... I believe. Once it has activated the spring becomes weak, and each time this happens it gets weaker and weaker.



If it runs fine without the TST, then you have probably solved your own problem. I am not sure which TST you have, but mine is an early R37 and it does not add pressure.



Might have to send it in for repairs, however I posted yesterday under the title "TST". Looks like they are moving, or selling out, so not sure where to send it to!



Oh, I see your TST in your sig.



Are you stacking with your Smarty? I cannot run any TQ settings on my TST, with any, any Smarty Downloads, runs like crap, misses, bursts, whatever. HP settings only on the TST with a Smarty on my truck, too much fueling down low otherwise, runs out of fuel.



Could also be your FCA.





The smarty was removed for the first voyage...



I got screw driver (to unlatch the plug lock) and managed to unplug the harness from the truck. Didn't go for a test drive yet. So I'll know tonight what's up. :)
 
The rail relief valve does not really "break", it is spring loaded to release around 26k psi... I believe. Once it has activated the spring becomes weak, and each time this happens it gets weaker and weaker.



Is there a way of maybe tightening the relief valve, if it is just a spring???



.
 
I removed the harness (as stated above) and put the smarty back on 9. All is fine.



The newest smarty software is all jacked up, however, I don't lose real pressure like I did with the TST (and not even smoke a poof). It drops a 3-5K when you get on the peddle and it comes right back up, typically with lots of smokey smokey.



I"ll be checking the relief valve tomorrow.



how does one check the fca?
 
if the FCA does not rattle when shaken like a PCV valve it is bad. . . however some FCA's that have rattled were bad. a burr may have developed that is causeing the cylinder to stick.
 
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