Hello,

I've been stalking these forums for years but have never bothered to register until recently. You all have been quite helpful in the past diagnosing problems and what not, so thanks for that!

Recently I purchased an OBD II blue tooth device and have been playing with my truck to see what kind of numbers I could get for various systems. While conducting WOT run pulling a steep grade I noticed that my IPR DC% would peg at 64.17% and my HPOP value while at WOT wouldn't go past 1800 psi or so. Immediately after i take my foot off the accelerator the IPR % would drop and the HPOP would spike to 2400 or so. Never any higher than 2400 under any circumstances.

After reading information on this site and others I kinda was getting the feeling that something might be wrong with my IPR, HPOP, or something else entirely. I had expected to see an HPOP somewhere alot closer to 3000 and a much lower IPR DC.

My truck is fairly stock, Ive had an AFE stage 2 air cleaner for years, I recently did the Hutch/Harpoon mods and a pre-pump filter with the Strictly Diesel kit. I also added an HPX tube. When I bought the truck in 2004 I was told it had a chip but I never bothered to verify that until this morning. When I pulled the PCM this morning I discovered a +75 hp chip installed from bully dog. This is a stand alone chip with no tuner display or anything to modify what the chip does.

I decided that I would pull the chip and do a road test without it and watch my HPOP/IPR again. While climbing the same hill under WOT my HPOP reached nearly 2900 psi and the IPR% never even hit 40%. Slightly slower acceleration up the hill but much smoother and boost stayed more constant instead of dumping/rebuilding.

I have never played with a chipped vehicle before (except the last 9 years I guess?) so is the data I collected with the chip installed common? Any enlightenment would be appreciated. Thanks in advance.

--Jason

 

Yes, the data you collected with the chip installed is expected with the Bully Dog product you have. This was the main reason why I discontinued use of Bully Dog chips and programmers. Their method, while crude...does work. The owner just needs to be aware that some PID values read via scan tool may be corrupted. The correct way to measure ICP with the Bully Dog chip installed is to set the scan tool to volts (vs psi) and do the conversion manually.

Have you looked at your boost value with the chip installed? When I was using a BD chip, my boost pegged at 19 psi and didn't go any higher even though my mechanical boost gauge would climb to 25 psi or so...

I am currently using PHP calibrations in two of my trucks via the PHX 6 position chip. So far I haven't found any PID conversion anomalies while using the chip with the exception of the boost reading. It's an accurate reading, but with a minor tweak that addresses the defueling issue. What they did is actually a little bit of genius in my opinion.

Sounds like your truck is running fine. Nothing to fix. Happy truckin...

 

Thanks for clearing that up for me. I'm glad I pulled the chip and discovered the difference in the values. It will certainly save me some unnecessary diagnosing time.

I dont have a manual boost gauge installed just yet but the scan tool (using the torque android app) max boost was 18 or so with the chip and around 14 without it. I'm pretty sure my turbo housing is leaking though. I noticed a skinny little shiny section starting to show up between the two halves while working on the truck the other day. So I'm gonna pull it and build it and the pedestal here in the near future. Thanks again!

 

10-4.
Stock boost normally is in the 15-16 psi range so you aren't far off that figure. The 18 psi reading with the chip installed was not correct...but again that is normal for Bully Dog to do that. If you decide someday to try some other brand of chip then I'd recommend the PHP PHX for a stock-ish truck. Value for the money is quite attractive and their calibrations are very refined. I ran Bully Dog stuff for a lot of years...it worked but had I known then what I know now, I would have gone straight to the PHX chip and been happier.

My two main complaints with Bully Dog chips and programmers are the PID lookup variances and their aggressive timing nature when the engine is cold. I was never able to actually see the timing values but the engine sure sounded awful when at WOT on a cold engine... It was obvious that something wasn't right with the programming so I resisted the heavy foot until I knew the engine was up to temp. The PHP chip doesn't have either of those issues. I presume the same is true for most of the custom tuner choices available these days.

 

After purchasing/reading/rewriting at least a dozen BullyDog chips off of ebay, I have yet to see one that actually "fools" anything when used on the correct corresponding PCM family. But then again, I won't argue because I haven't seen it all....just a lot of it.

As for the injection control pressure "issues", they come with the territory when asking for more than 60-80 additional rear wheel horsepower from injectors that are long since empty and still "on"....... NOBODY is immune regardless who does the tuning. The only way to help avoid running into this problem is to use what's commonly referred to as an inferior product on any forum; an injection control pressure fooling device or "10K mod"...but you'll get chastised beyond belief for liking one of those things. The best programming for a lot of my work trucks (who are driven by guys who can bust an anvil with a rubber mallet) is nothing but a "tuned-in 10K".

 

To the op dont go blaming bully dog. I had an identical problem almost exact same numbers too from my tuner. I just pulled it off completely a few hours ago and found the exact same thing icp was 2900 and ipr was around 34%. The truck felt very very strong and made good power very close to my 80 economy tune. The only real difference was the turbo took a half a second longer to spool but the 15-17 psi boost that I was expecting got thrown out the window when I watched it hit 23 psi.
Good luck

 

Stock boost is only 15-16? I hit 18 all the time in mine with just intake and exhaust.

 

Normally yes. 16 psi is about what I see on many of the trucks I have access to. My '99 pickup hits 18 in stock tune though....all trucks are not the same, some are higher.

 

I just didnt know. I didnt put gauges in till after the exhaust and intake.

 

I have personally witnessed a Bully Dog 'flip chip' change ICP and MAP values when viewed with the AE scan tool. The volts read accurately but the psi value was changed.

I have not seen this happen with my PHP chips with the exception of the boost observation that I mentioned earlier. I am sure you know exactly of which I speak....

 

The likes of which I have seen with another vendor's brand of tuning, but never BullyDog. It's easy to accomplish, but after seeing many different strategies used by BullyDog over the years and the minimalist-yet-sledgehammer approach some of their calibrations have, it really amazes me that you ended up with one that changed the function relating to MAP voltage.....

I'm certainly not saying that you're making this up....I just would like to see it in the calibration. I know we've thrown this conversation around before so I won't go any farther into it.

 

I suppose it is possible that even though the product said "Bully Dog"...it may have had a different calibration written over. I inherited the chip when I purchased the truck so the previous history is unknown to me.

It was quite amazing actually....just sitting at idle and switching positions would change the MAP value from near zero to -2.0 psi and even -4.0 psi depending on the position.
If I remember correctly....the Bully Dog Power Pup programmer did not change MAP at idle but it did top out at 19 psi in the higher hp settings.

 

That could be the case (but it will be one of life's great mysteries). I find it weird that the OP seems to have the same symptoms....which means that you both could have easily ended up with a BullyDog chip in which the calibration engineers were able to keep the defueling to a minimum. There are many ways of doing just that, mind you.

As an aside, the chip that I loaned to Tugly in the interim before he received his Hydra said "BullyDog" on it too.

Regardless, as long as the OP knows what is happening with his particular truck and tuning, there is no foul.

 

I'm gonna jump in here and say I didn't have a bully dog and stated that I had the exact same problem as the op.

 

I appreciate all the input from you guys but I have one variable I forgot to mention. The run I described with the chip where I had hpop at 1800 and ipr of 65 was after I had just rebuilt the ipr and today after fiddling with the truck I noticed that the 3/4" nut that holds the ipr sensor in place had backed off and the ipr was rotating freely.

I'm thinking now that while the pcm was increasing the ipr % the valve was likely not opening/closing as it should in response to that signal thus my low hpop reading. After correcting the problem I did another road test and I consistently got an hpop around 2400 and ipr of 65.

I'm not sure why I have reduced hpop with the chip vs without it but my best guess is the chip is either pushing the limits of my fuel system or hpop. I'll have my gauges installed tomorrow so ill be able to do another run while monitoring fuel pressure and I imagine that might isolate it to the fuel pump or possibly injector performance? Im new to this so not 100% sure how it all works but I'm looking forward to figuring it all out. Regardless the truck runs great stock and I can't wait to get some more mods