I now have my RP gauge in, & was able to take it out on the highway today. I cruse @ 60mph @ 17K+/- @ 1600 rpm. If I get on it some it will drop to12K+/- & stay there as long as I've been able to see.(still snow on the roads).Thats in O/D. In D it wll drop to 15K momentarily, & climb fast to 24K+/-. This is on TNT.
SW-9
TQ-2
TM-2
RP-2
WG-off

 

if it drops momentarily then climbs back to 23,000 your good for now.i would think. im on a stock cp3, with an arson kit which i just got.

 

if you have the extra money to spend on a bigger cp-3 go for it. It will not hurt anything and if you plan on going to a larger injector later you already have the injection pump done.

 

Upgrade. You will be much happier afterword.

 

Are you sure you have it hooked up correctly, If it is backwards it will read different. If you have stock stixs it can't me draining your rail that bad......if it is hooked up right then yes an upgrade is in store for you in the future. Make sure its pluged in, in the correct order. Did mine wrong the first time and it read like yours did.

 

I have stix and the II bag of parts and have no rail pressure issues even when I had the 1.8's in.

 

I know it's hooked up right. I have just the TNT on it. I know I'm holding fine in drive. I'm just wondering if I'm draining the rail "some" in O/D. Hopefully I'll get to run it over the passes tomorow, & get a better idea what it's doing.

 

I guess I have a question slash answer... The CP3 is RPM dependant correct? Since it is RPM dependent it makes sense that your rail pressure would drop like that in OD. Like I said That is my understanding on it, but could be wrong.

 

The drop is normal and more pronounced in OD, particularly at low rpm's.I have a stage 3 pump and see the drop also,just not as bad.If your speed and rpm's are up the drop will not be as bad and recovery will happen quicker.The TNT tune is the worst on my truck for causing this.The beta's do not show near the RP dip before recovery.I have wondered why this is?

 

I know that CrashCade got the reason. without engine speed the pump can't flow as much fuel. I was wondering if a bigger pump would eliminate this, but sounds like it won't. So that answers my question. I don't have the coin to do an upgrade anyway, & my truck runs GREAT as it is. Thanks for the info.