So I just got my new (lightly used from E-bay) Predator the other day and as one would expect, I immediatly went out to play! But I seem to have a wild erratic shift when I stomp on it in either the 60 hp or 85 hp modes. It feels as if it is "hunting" for the right spot, and is still present with the overdrive off, though not as much. I do have gauges, and the boost seems all over the board once over 10, it''ll get up to about 20, then drop like a rock back to 10 and all in between. I have also barely seen the SES try to light, I'm assuming this is due to an over-boost as I have read on other post. So, is this simply an over-boost issue in which the engine is de-fuelling? or do I need to do an update on the Predator itself? I have read that some are not happy after an update-weaker tunes.drop like a rock back to 10 and all in between. I have also barely seen the SES try to light, I'm assuming this is due to an over-boost as I have read on other post. So, is this simply an over-boost issue in which the engine is de-fuelling? or do I need to do an update on the Predator itself? I have read that some are not happy after an update I believe r19-weaker tunes. Or is this a problem within the unit itself?

 

i am no expert here.. but boost dropping off like that sounds like a defuel do to overboost... that defuel has to play havoc with the tuner... just my opinion... i would do something to prevent that overboost problem... AND... since you didn't buy a new predator i would update that too...

 

Did you install a Boost Relief Valve to limit the boost to less than 22 Lbs? That would stop the defueling, but not the overboost (SES will light for about 1 minute)

 

Thanks guys, no, I have not put a regulator in yet. Does that sound normal to have the boost bounce around like that? I have not seen it go over 20. Is there a newer update that people are happy with? I am in the process of trying to get a regulator to see if that helps. Thanks again!

 

I do not think it is an Over-boost problem. You will not get the SES light and defueling until around 24psi of boost. I never saw mine come on at 20 psi. I did however see it come on, on que at 24 psi every time but the boost did not drop like you explained. It just did not go any higher; it stayed between 23 and 25psi bouncing. After I installed the over-boost eliminator kit it cured all my problems and the SES light does not come on and I can hit 29psi. The kit stops the MAP from seeing anything over 22psi. At 22psi, that is at the max fuel your computer tells to send so the relief is set there to maintain max fueling. Must be something else if all of this is happening at only 20psi.
Hope this helps.

 

where can i get a over boost illmanator?? my check engine comes on all the time... is this bad for it?? should i plug the wastegate back in?

 

I got mine from WWW.ITPDIESEL.COM.

 

radracer17, I also have a diablo predator and have the exact same problem as you do. Did you ever find out the cause??

 

Sorry Titan, been away for awhile, actually, I did get it rectified by installing a simple regulator as I had suspected (and hoped) after reading the other post on the board. I personally picked up a basic unit with gauge from Home Depot. I welded up a little bracket to hold it nicely with the factory bracket that holds the sensor. Hope that helps>