I'll vouch for that one.
Mine died with nary a code thrown.


phox

 

You must get it scanned!! More often than not, these trucks will NOT throw the CEL if a DTC is present!

 

Just got back from getting the truck scanned ... nothing, not one code. So where do I stand now? Should I just go ahead and trade it in for a Ford ... LOL! Sorry, I lost control there for an instance ... please help!

BTW: I don't know if this helps, but the current VP was installed at 95K ... I'm now at 129K.

 

I would think clean the MAP and IAT sensors.

 

Let me get this righ; if I am WOT, pulling a hill, pushing 18-20 psi boost and 1100* EGT's, I should be seeing some black smoke? Never have I seen this.
I've heard of cleaning the IAT sensor, but not the MAP sensor. What/how do I clean it? Would clogged injectors do this? I checked my air filter and it seems fine (less than 10k on it). I'm at a loss on the fuel issue. I thought the ECM was supposed to control the rate of fuel???

 

I don't think anybody mentioned it yet, but could it be the waste gate is not closing properly(partially stuck open) causing the boost not to build up to full pressure. Is the boost quick to rise or slowly?

 

The boost rises quickly. When I get on it, it's almost instantaneous. How would I check the wastegate?

 

Put a clamp on the wastegate to keep it closed at all times and see if your boost will go up any. With it locked shut you should be able to get a lot more boost!

But if it rises really quick, chances are that it's working properly. If it was stuck paritally open it would be a lot harder to build any boost because all of your pressure would be escaping. But try the clamp anyway, its worth a shot to make sure it's good!

 

not sure, was more thinking out loud as you said that you could not build boost over 16psi. if boots are ok not leaking, imo the wastegate might not be operating properly. eg opening to soon(dirty sensors like mention before), stuck partially open. Someone with better knowledge of wastegates may have an idea on how to check it. sorry couldn't be more help.

 

And since you have a 99, I think you should have a hose going from the wastegate to the turbo instead of the hardline like I have on my 2001. If that's the case you can take the hose off and shoot some air in there at different PSI #'s and see what psi the wastegate is opening at. That should tell you something, or just as easy install the clamp that i metioned previously

 

Clamping the wastegate actuator line and forcing the WG not to open without a boost fooler will likely cause a stock engine to make LESS power than before.....If boost goes over the max preset limit (20 psi), the ECM throws a 0234 overboost DTC and will defuel the engine to keep the boost in check....less power is the result.

Piper,

I must be misunderstanding you..... IIRC, you previously stated that the max boost you were seeing was only 16 psi while towing 12k.....now you are seeing 20 psi? If you see 20 psi, that is right where a stock 24v should be.....if you are only seeing 16 psi without consistent black smoke, you have a lack of fueling. And no, a stock CTD operating correctly should not emit any consistent amount of visible smoke. If there is visible black smoke and you only have 16 psi of boost, look for a boost leak or a malfunctioning wastegate.

 

WHOOPS my bad, I thought that I read in his sig. that he had a chip installed!! Guess I should get my peepers checked And yeah you are right, without the boost fooler, locking it shut won't help it at all.............

 

Let me clarify:

When I first noticed the problem, about 3 weeks ago, I only saw 16 psi and around 1000*. This past Monday, I towed the boat again (12k lbs). This time I tried to push it and saw 18 psi (max) and 1050*. My son was my passenger and kept his eye on the exhaust. All he reported seeing was a short puff of black smoke on the initiation of the pull on the hills.

Yesterday, I got on it on the way back from getting her scanned. Pulling a relatively steep grade, at WOT, I was able to see 18 psi and 1100* (unloaded). No matter how hard I tried, I was unable to get the boost any higher.

I read that 18-21 psi is normal for a stock truck, is this true?

 

I really doubt elevation would play a factor on a stock motor but I suppose it is possible. IMO, it is NOT normal for a stock 24v to only pull 18 psi of boost @ WOT......usually, when equipped with a boost fooler, a stocker is capable of 24-25 psi. The engine should easily be able to fuel all the way up to the wastegate setting - especially when towing 12k. With only a puff of smoke on initial hard acceleration, I'm inclined to think that there is not boost leak or a sticky wastegate....With no DTC's, it could be possible that there is some sort of injector problem.....the only way to be certain would be to pull them and have them tested.

 

If there is a possibility that it's the injectors, I'd rather change them out to RV275's. That has been a plan of mine for some time, but I couldn't justify the expense. If I was to go with the 275's would I need to modify the truck in any other way to support the added hp/torque?