More trouble shooting woes with my vacuum operated boost solenoid wastgate...?

[Crankme69]

Ok somin ain't right Lucy!

Latest observation this morning on my way in to work...

The wastegate actuator seems to be shut all the time WTF???

It's getting real close to TM time, I surely do not want this thing running at 20+ boost numbers at WOT!

It stayed at 20 psi + this morning at WOT getting on the expressway until it coded out & cut fuel...it does not appear that the wastgate solenoid signal is able to move the wastgate actuator, the boost is now being maintained by the go pedal position.

3 Codes this morning...(1) for boost solenoid & 2 more for EGR chit!

Grounds maybe friggin chit! :sad:

 

[96 OILBURNER]

Spray some WD-40 in the solenoid, it may be stuck.

 

[Crankme69]

I'll try it again...just replaced all the vacuum lines and did that last Saturday thanks!

 

[Diesel -T]

Dont remember if vacuum lines hooked up incorrectly could cause such a problem?

 

[Crankme69]

Yea I thought about that also, they are hooked up per OEM schematic on the fan shroud except for I have the EGR line capped off...

 

[buddy]

Could have a ground or short gremlin causing all of the solenoids to go to 100% when they shouldnt. There is no reason to have EGR codes from overboost, so it must all be related or multiple solenoid failures.

If 100% duty cylce then the PCM is throwing constant power at the solenoid to keep it wide open. So it may not be getting the signal back or the ground is shorted. They run off IGN voltage through a solenoid fuse, all from same source. Then they are all grounded separately in the PCM to control them. So a few of those wires may be faulty.

So if there were a single ground to look for it would be the PCM ground, which should be on the passenger side at the rear of the block, and intake manifold.

You can check the solenoid harnesses for shorts to engine ground on "B" pins.

At idle, you can try checking vacuum through the boost solenoid, then unplug the solenoid and make sure vacuum is cut off too.

 

[Crankme69]

Thanks I give a look see after I get home tonight...

 

[Crankme69]

Nice clean 6.5 that someone is going to end up with for cheap mother friggin electrical chit!

 

[Veg_Out]

You might want to check the grounds and connections on your boost gauge. If you are hitting 20, look out, parts are going to fly.

 

[ak diesel driver]

seems like I read a thread that someone had reversed the hoses on the selenoid and caused the same problem.

 

[JiFaire]

seems like I read a thread that someone had reversed the hoses on the selenoid and caused the same problem.

Yep - think about how they work.

You got a hose wrong somewhere, CrankMe. Your EGR code is caused by that being capped off without a reflash, but your high boost is easy to solve.

Don't give up on her yet!

 

[Crankme69]

Hey thanks guys...

Sometimes ya need to walk away from it for a while.

Let me start out with the series of events that have lead me to this perceived electrical nightmare.

About 2 weeks ago on a Friday my SES light popped up on my drive home...the motor seemed sluggish so I stopped the truck & checked the wastegate for vacuum, it seemed to have plenty holding the gate closed?

That event then triggered a no WTS light, so I changed the GP controller out, busted the old one taking off one of the leads and after changing that GP controller still had NO WTS light...I thought here we go let the nightmares begin.

Well after reading as many post as I could find...I found the a fuse blown for IGN A in the fuse box and replaced it, all was fine for about 2 hrs, then it blew the fuse again. So being the electrical nit wit I am, I desided to replace the 20 amp fuse with a 30 amp. The 30 amp has held and the WTS light has been working ever sinse that.

EGR codes were being intermittenly set and I am kinda now thinking one of my EGR or Wastegate solenoids are possibly the culprit.

Hooked my GMTD Scan Tech and watching the screen my Baro Map sensor indication has been jumping around, so I removed it sprayed it down with WD 40 & reinstalled it, made no difference, one reading was even as low as 2 psi, now that had some interesting things going on with the reading on the wastgate duty, not to mention the calculated boost pressure on the GMTD screen...I realize that calculated number was way off due to the baro reading being fuebar.

Last night I changed out the Baro Map sensor with a new one, all seemed fine for about 10 min after I changed it, then the reading on the Baro sensor would again drop from 13.75 to 11.1 and set an EGR over pressure code, I'll verify the actual code numbers the very next chance I get and post them.

I will clean the grounds and was planning to do them all as I have an F intake to install...was just hoping all this chit would wait...guess not.

I drove my car today, gave the 6.5 a day off until I can get this all sorted out :mad2:

 

[Pruittx2]

At least your on the right track now,, good to hear that. I know it can get Very frustrating sometimes, and a good walk, and some post reading is all thats needed.
It's funny that with all of the short comings, of the factory design of our beloved 6.5's A group of gearheads like ourselfs can get it done, and make it better. Just be Glad that Obamha, and Government Motors came along to late for our trucks sake, just think how bad they could of screwed that up!

 

[Crankme69]

lol

 

[buddy]

Plugging the EGR on the OBD1 wont cause the EGR codes as long as everything else is working correctly.

Ah, an electrical short somewhere then is quite plausible. Would the truck still get an SES light with that fuse blown, and even run?

 

[Crankme69]

Plugging the EGR on the OBD1 wont cause the EGR codes as long as everything else is working correctly.

Ah, an electrical short somewhere then is quite plausible. Would the truck still get an SES light with that fuse blown, and even run?

With the IGN 20 amp fuse blown, the truck ran, the SES light was spuratic and seemed to clear at specific RPM's maybe the RPM's were just coincidence???...but I had no WTS light after shutting it off.

 

[buddy]

Here are some schematics then for the 94 "Gauges" fuse, which sounds like its just like the 95 ECM-A fuse.