I was messing around under the hood of my 7.3 today, and saw a red line that looked like a vacuum line that was going nowhere. It looked like there was a nipple fitting that had corroded and broken off in the loose end. The other end was connected to something that looked like a solenoid valve at the junction of the intercooler pipes. The location of the line suggested that it may at one time have been connected to a doohickey on the turbo. I shoved it back on there, but with the broken connection it probably won't stay.

A little googling tells me that I was probably right about where the line belonged, and that doohickey is a wastegate actuator. How big a deal is it to have that line not connected? I've seen talk on some forums about people deliberately disconnecting it. If I understand correctly, its purpose is to prevent overboost damage. If my truck is stock, is there really much chance that I'll get too much boost? Are there other issues involved?

I'm probably going to replace the actuator and line anyway, but am I taking a big risk by driving the truck before I do? Should I plug that line instead of leaving it jammed on where it's probably ineffective and might fall off? What happens if that line is just dangling sucking air instead of actuating the wastegate?

And how tough is it to replace that? Are there any gotchas? Do I just remove the old one and bolt on the new one? Or is there some critical adjustment that will cause my truck to blow up if I don't get it set right?

 

Many folks unhook that line to get a little more boost. If your truck is stock, a couple pounds extra is all that I would expect. Any danger? Well, do you have a gauge on your truck now? If so, how much boost are you making?

Here's the thing:

In stock form, about 18lbs of boost is all you'll make. Pulling the line will maybe get you to 20lbs of boost.

If you start adding some mods, you will raise those numbers. A 4" exhaust, and a better flowing intake may raise it a pound or 2. Add a chip and 24lbs is the most you'll make until you add a boost fooler. The engine defuels at 24lbs of boost unless you've installed a boost fooler. When mine defueled, it dropped to 12lbs. I've since added a boost fooler, and a 38R turbo which spools a little quicker, and 30lbs of boost is not hard to obtain. And the red line is plugged in on this turbo.

 

As John said, bag the line if your worried but unless You make aggressive mods don't lose any sleep.

Truck running allright??

Denny

 

You can buy the rubber boots at Oriellys/ Autozone etc. They come in an assortment package. Make sure it is connected back up, or plugged off at the boot. You can push the boot on to the Intercooler clamp. Also, it does pull vacuum, so again plug it somewhere. It should throw a code, maybe just a soft code though, if it's not working/connected properly.
Campspringjohn, I see your running GH tunes, Matts tunes do not require a boost fooler. He does it all with-in the tuning.. It will actually hurt your tunes by means of less boost if you run a boost fooler with GH tunes. I don't know about swamps though. I thought everyone was tuning this way now, but I could be wrong. I know Matt does though.
On Edit: Also, it's good practice to put a Vacuum plug on the turbo side if you do remove the red vacuum line. It'll just keep the dirt out.

 

Really? I was not aware of this. As far as I can tell, Swamps does need the boost fooler to keep from de-fueling. I will experiment on this, thanks. I also have PHP tunes, do you know if that applies to them as well?

 

If you got a properly performing truck with no leaks..etc, I'd leave that puppy hooked up to w.g.

 

Don't need a boost fooler with PHP as far as I know, I've seen 30# towing uphill with my 38R

 

That would have been my first choice. I wouldn't have intentionally unhooked it. But at this point, leaving it hooked up may not be an option. As I said, the nipple on the actuator where the line hooks up is corroded and broken off in the connection boot. so the line is just jammed into place and probably won't stay. So my options are to replace the actuator so I can hook it up securely, or leave the line dangling and plug it somehow.

 

I would plug the red line and dust my hands off.

The boost fooler is not to prevent a chip/performance tune from defueling - it's to prevent a stock-tuned truck with air mods from defueling. Most chips/tunes prevent an overboost code, but some do not. For chips/tunes that allow an overboost code (about 27 PSI or more), the boost fooler prevents that. I have Stage II sticks and a 38R with live tuning, so I installed a boost fooler to keep from blowing the MAP sensor... again.

 

John, I don't know about php, or swamps for certain, but I do know that Matt does for sure only because I run his tunes and only his. I recall with in a conversation we had one time him asking me if I had boost fooler and if so to remove it because he tunes around it, so no need for one. I would definitely call him or shoot him (Matt) an email and double check. I have a pretty extensive build that we're working on with the tuning, but I'm almost positive Matt tunes all of his out going tunes this way, no boost fooler..

 

I was running Swamps for several years. I installed a set of 200/30% hybrids from Swamps last year. I also got a PHP Hydra with tunes from Swamps as well as PHP. After reading a lot about Gearhead, I decided to get some tunes from Matt too. I had the Boost Fooler on the truck before I did the injector install, and just never thought I didn't need it. It certainly is easy enough to unhook and try without it! Thanks! Tugly says he still has one because he keeps damaging the MAP sensor. Anybody else have that issue?

 

I think your spot on here Rich with how the Tuning is controlling the Map/boost/over boost. I too believe that most tuners do this now, but again I'm not completely sure. I too have a 38r that's been on my truck for about 13-14 yrs with 238/80's, but I've never blown a MAP sensor and I regularly pushed that Turbo hard to 38 lbs. Wow, again never heard of that happening. With the new build I'm running I had to back off my waste gate because my 38r would hit 45lbs very quickly. But I'm also running a Billet Wheel and 6.0 MAP sensor too. I'm sure that's why. Apologies to the OP for the Hijack..

 

Yup, you did mention that the nipple was broke off Matt. I missed it the first time I re-read your post. As you said, just plug the red line off, shove it on the Intercooler clamp to keep it closed off and secure. Boost comes on quicker with the redline disconnected and plugged off.

 

Uh? How high does a 6.0 MAP read? My 7.3L MAP only reads to 49-50 PSI (absolute) before is electrically tops out. If I were to change to a MAP with a higher limit, FORScan, AE, and the PCM could read it wrong - or not. The MAP sensor uses frequencies to feed pressure info to the PCM, and the PCM converts the frequencies to pressure readings. Does the 6.0L MAP use the same frequencies for the same pressures and just go higher... or does the 6.0L MAP condense the wider pressure range into a limited frequency range?

The key question being - is the boost reading on the OBDII port the same as an external gauge, or does the boost read low on the OBDII port?

 

Tugly, I don't recall the details of the conversation I had with Matt about the 6.0 MAP sensor swap. I have a pretty extensive build, so there was an advantage here for me to do this, I just don't recall the details.
I sent him and email with the questions you posed. I will relay his reply as soon as I hear back.
I do have a scangauge along with my A pillar AM gauges installed on my truck. The scangauge does read the MAP slow and low compared to the Autometer gauges. Other Scangauge reading such as MPH, ICP, & IPR readings are very quick to react, so it could be that the 6.0 map is messing with the ecm here.