7.3 can't make power - 1247 low boost
 

This is my first 7.3 so I am not sure what to expect from it. I am having a LOT of trouble pulling my 9000 lb travel trailer which I would expect it to pull with ease. I’ve done a lot of repair work on the truck since I bought it two months ago, mostly cleanup / maintenance. Since the power felt low I added a SuperChips Tuner to it, I ran it in “safe tow” mode this weekend for our first towing outing. I also added ISSPRO boost and pyro gauges with the tuner just to be safe.

Once up to highway speed it runs at about 5 lbs of boost, 2100 RPM and 1050 degrees (it was painful to get to 65 mph) . This is on flat ground. As soon as I hit a SMALL incline I either have to slow down or watch the EGT shoot into the red (1250+). At WOT in 4<SUP>th</SUP> gear at 2500 RPM the most boost I ever see is 8-9 lbs. When I got home I checked codes and found 1247 Turbo Boost Pressure Low and 1211 ICP Not Controllable Pressure Above Desired. For what it's worth I went back out for a ride in stock tune mode, the performance was worse as expected but the temps were just as bad.

Here are a few engine related things that have been done / checked before this trip:
<O:p</O:p
- Removed the IC pipes / boots cleaned and re-installed (minus foil)<O:p</O:p
- Added ISSPRO boost and pyro gauges<O:p</O:p
- Changed MAP sensor hose, it was cracking when I installed the boost gauge “tee”<O:p</O:p
- Fresh synthetic oil 5w-40, new filter<O:p</O:p
- New fuel filter<O:p</O:p
- 6637 Intake mod (thanks to all the advice on this site)<O:p</O:p
- Checked glow plugs due to starting issue, found 1 bad and replaced<O:p</O:p
- New Batteries

What can I do / test next? We are going to the Pocono 500 in two weeks and I’ll have to take my Dodge (CTD) if I don’t get this resolved!! :-banghead<O:p</O:p
<O:p</O:p

Thanks,<O:p</O:p
John<O:p</O:p

8-9 PSI of boost is way low ! Sounds like you have a turbo issue to me ! I get about 18 PSI with my chip that I have now and that should go up when I get my DP tuner installed very soon ! Look for other turbo leaks ! Up pipes may be leaking..look for soot there as well !

sorry bout your issue, i jus looked in my 7.3 book and its a MAP Sensor Code, it could be this or the turbo., the other code is the IPR valve is failing, stuck, or shorted

Any ideas on how to troubleshoot it? I know the boost is way too low, but how do I find the cause?

I'd buy a new turbo now if I was sure it would solve the problem, but I'd have to explain it to my wife if the truck was still "broke" after spending the $$$...

You definitely have major exhaust leaks somewhere to rob you of all that boost. A leak = loss of power also, and would cause your EGT's to jump up like yours did. The Superchip is definitely capable of boost levels up to 26psi. I just made the change recently from Superchip to DP. After you find your leak, which is probably up-pipe and another leak also.......think about selling that Superchip and getting a DP. I know that is said in every other post on here, and probably gets old reading.......but I know first hand! The maximum setting on my Superchip is slower then my 60hp tow setting on the DP. Good luck with those leaks!

I agree with all of the above, have you looked at your turbo wheel to check condition?

As Wes mentioned.. Check that MAP sensor. Good idea Wes.... I had a no power issue when I first got my truck and it was the fitting on the bottom of the MAP sensor was broken off.. The MAP is around 100 bucks if I remember correctly,.. maybe less ! Thats kind of where i would start if thats the code that came up.. and as I and others have mentioned before.. check those up-pipes !

RussB,

Since the computer reported the problem (low boost) and I have a gauge that verified it, wouldn't that mean the MAP sensor is working? Does the MAP sensor control the boost or just monitor it?

Thanks,
John

Edit: What filter did you have before the 6637? Was it just the stock set up? As Jim mentioned, take a look at the turbo wheel.

Here's some reading for you.

John,

I pull a 15K 5er, and I would say it's a little slow getting up to 60, but once there it will hold that speed below 1300 EGT up some pretty steep grades without much trouble. Pulling only 9K I'm guessing it would feel like a stallion. I use an Edge Evo II and the on-board pressure sensor has never shown over 15 lbs, usually 14 max WOT and pulling a grade. 5 lbs is bad. Got to be something wrong with the turbo or sensors. The 7.3 is a real strong motor.

I agree with you here, the map reads and your gauge confirms. I would first check the turbo out make sure it appears in working order. Check the compressor wheel. Then look for all the leaks possible; you can make a jig and pressure the system with 25lbs. If it is leaking on the intake side you will find it for sure. Do you know if the waste gate is stuck open? You might try disconnecting the red line to the actuator to see if it helps any.

Someone that knows more about it might chime in but I think the MAP sensor controls the amount of boost more than just monitors it ! Not 100% on that...

When my tube was broken off the bottom I got no SES light on or anything.. Just no power / no boost ! I think you have a major leak ! Process of elimination at this point !

Thanks for all of the info and responses. I know the hose and connection to the MAP sensor is OK since I replaced the hose when I installed my gauges. But it looks like I have a lot of connections to check out and some sensor testing as well.

I know my turbo wheel is in rough shape, here's a picture. I'm not sure how bad this is, it was the reason I changed out the factory air filter for the 6637 mod.

http://lappie.org/photos/posts/Turbo.jpg

John

Man that is not good, however, I have seen worse wheels that that. If you are going to run a tuner I definately suggest getting a Wicked Wheel seens as it would be a good idea to get a new one before long. I don't think that is the cause of the low boost though.

Ouch! :eek:

First off the P1211 is a very common code for a PDS with a chip. It is saying that the HPOP is unable to maintain the pressure that the chip is calling for....

The low boost code can be caused by a few things... First off crawl under the truck and look at the up pipes to the turbo. If they are leaking badly you will see lots of black soot around them at the top...

Next you need to build your own or buy a boost leak detector. Here is the Dieselsite version:

http://www.dieselsite.com/ProductIma...ducts/blt4.gif

You remove the air filter and plug that in, pressure up the system and check for leaks...

If you have no exhaust leaks up to the turbo, and no boost leaks, then the turbo is no good...

Good luck!
Bob

How bad of shape would you guys say that wheel is in? Makes me want to go look at mine now......been awhile since I inspected it! And I ran the K & N drop-in filter for forever! :eek:

Mr. Bob,

Is the system supposed to maintain pressure or do I just crank up the flow to maintain pressure while I look for leaks? How much pressure should I test with?

Thanks for the advice and especially a photo, I can make one of those with parts on hand.

John

I think he said 25 PSI .. its in a previous post on this thread !

Put it in the inlet of the turbo and apply between 10 - 20 psi from an air compressor (with regulator) If you can't hear the leak try spraying soapy water around any connections.

Try this!
I bought my first 7.3 a year ago. It obviously didn't have right power. After MUCH checking, some one suggested I change the MAP, and that solved the problem. My understanding is that the MAP senses the boost and allows the computer to add fuel accordingly, which of course adds boost! With no added fuel you will get no added boost.
Anyway, why not try it? Just swap MAP's with a friend to see if it makes a difference. It only takes 3 minutes. If your MAP is bad, you and your friend will both know it!
It sure fixed mine. Best $90 I've spent on it, and it is lifetime guranty at O'reily's!

I checked the up-pipes, yes they are both leaking at the top judging by the black soot streaks. I'm not sure how much they are leaking but they are leaking. No leaks from the bottom connections.

I pressurized the intake to 15 PSI and found no leaks on the IC pipes or connectors, but I did find air leakng from the MAP sensor. Is this normal?

So I disconnected the MAP sensor just for a test drive to see what happens, the system definitely noticed since the check engine light came one. But it runs EXACTLY the same as it does with the MAP sensor plugged in. What SHOULD it do with the sensor disconnected?

Thanks for the advice, I'll keep chipping away until I get this thing running right!

John

Where was the leak at the sensor? Was it in the hose or at the sensor? Either way the leak should be fixed.

If you unplugged the electrical connector on the MAP then the PCM is supposed to assume default readings, which means it would have ignored your leak if that was the problem.

I'd guess it's time to play with the up-pipes. I'll look through the manual and see if I can find any other ideas.

The MAP sensor seemed to be leaking at the seems of the plastic case. The hose is new, I changed it when I added the boost gauge last week.

I'll se if I can find a new MAP sensor tomorrow, my local AutoZone doesn't carry them, special order only.

Thanks,
John

Sounds like you'll have it fixed when you put in that new MAP.. Good work on tracking the problem down !!!!

would low boost result in not as definate and loud whistle?

Well I replaced the MAP sensor with one from NAPA on my way home from work. $105 with tax! ouch!

In any case I can't really tell if there's a difference or not. I haven't towed my trailer yet, but getting on an up hill highway ramp with the pedal to the floor I got about 11 lbs at 3000 RPM. Is this similar to what others are getting?


QUICK EDIT --- Every time I read about someone installing a 6637 they talk about the great sound the turbo makes. When I installed mine I didn't hear ANY difference.. Maybe my turbo is dead?

That one look pretty bad almost like it was run with no filter


if the boost is low it won't hardly whistle

how much boost are you making between 1800 and about 2300 at full throttle?
I really don't think you will get a lot of whistle with the shape the turbo is in

Ray,

The boost is low between 1800-2300, like 5-6 psi, even with my foot to the floor. It doesn't climb to 10 psi until aroun 3k.

I'm really trying to get this resolved. The truck has little blow-by, starts right up, does not smoke etc. I think the engine is in OK shape, but the low boost / low power makes it a lawn ornament. I'll have to get my Dodge ready for the Pocono500 next weekend, there's no way I can tow 100's of miles with this one yet.

Thanks for any and all advice.

John

for sure you need a new compressor wheel and with 155k miles it could probly use bushings also,some have put more miles on without bushings being bad but mine were gone at 55k
with the shape the wheel is in hard to say if compressor housing is scored or not
only other thing I read you haven't addressed is up pipes but think turbo is biggest culprit
one other thing I had early on was a plugged muffler,thinking that could br why turbo died so early

I really don't like to send anyone after expensive repairs without seeing problem first hand

Ray,

Thanks for the advice, I don't like expensive repairs much myself... :-)

I was thinking about the muffler also, it looks original. I may gently remove it (Sawzall) this weekend and giev it a try. I was planning on a 4" turbo back system anyway. No time like the present!

If it needs a turbo I'll do the up-pipes, exhaust system and turbo at the same time. It looks like with the exhaust and turbo out I'll have the best shot at the up-pipes. Have you heard people mention new IH up-pipes (bellowed)? Anybody have a picture or link to them?

John

If you still have your stock exhaust you can disconnect the two bolts that hold the downpipe to the exhaust system and it will separate from there. Very easy way to open up the exhaust to verify a clogged muffler or not with not cutting pipe at all.
I think that the bellowed pipes are on national back order right now, due to the fact that work got out about how good they were and all the inventory got sold. They are in the process of making some more right now.
Is the wastegate lever adjusted correctly?
Or perhaps the spring inside the canister is broken?
If you apply some air pressure to the diaphram canister that is mounted on the rear side of the intake housing the lever should not move until at least 5 psi is applied. I have mine set to not moving until 10-12. The adjustment is done by disconnecting the lever from the rod and turning the end to adjust it for length.

Thanks Dan.

I'll try the wastegate adjustment you mentioned, it's one more thing I can try before spending big bucks. How can I tell when the wastegate is open / closed? Can you see the opening?

John

It will be closed when the lever is pointing straight back. Apply a little air pressure to the canister and the rod will extend, moving the lever. Wastegate is now open. Release the air pressure and the spring pressure inside the canister pulls the rod, pulling the lever back to the closed position.
Wastegate default position is closed with the spring inside the canister holding it closed. If you can move the lever with your hand easily without adding air pressure, you just found the problem. If it is properly adjusted with no problems that lever is VERY stiff to move without air pressure assistance to the canister.

Oh, and get some spare clips before you disconnect the wastegate lever. They like to go into orbit when they come off and it is much easier to buy a few spare clips ahead of time rather than sweating, trying to find the single one you just lost.

John,

Have you tracked down the 1211 ICP code? Possibly a bad ICP sensor. Unplug it and go for a drive. With the ICP unplugged the PCM will default to an internal fuel map. It will not hurt to run the truck with it unplugged.

Dan,

You hit it on the head!! I looked over the wastegate, it looks OK, it's hard to pull open. I put some air pressure (<10 lbs but hard to measure that low) and it opens up. It closes nice and gently when the air is removed.

So I decided to remove the hose from the actuator and plug the hose. I could tell the difference while backing out of the driveway, the first time I've heard the turbo whistle! I took it for a ride around the block, if I put my foot into it the boost would rise quickly to 12-13 lbs.

I took it back home and hooked my 9000 lb trailer up to it and took it on the higway. NOW I have a grin on my face. It pulled it up the ramp with ease, accelerating to 70 it hits about 20 lbs of boost at 2500 RPM. It stayed less than 1000 degrees EGT the whole time. Cruising at 65-70 was smooth, plenty of power and cool EGTs.

So, maybe the wastegate is mal-adjusted? It sure works great without it..:) I still need to fix the up-pipes, maybe that's why it was soo low on boost in the first place. Is there any harm running like this?

glad it turned out easy
if you are only building 20 lbs it won't hurt to run it that way,the turbos really don't like more than 25lbs and it shouldn't defuel til 22lbs

It seems the boost you were building was going straight to the WG actuator or the actuator spring is super weak

Sounds like his was set to 10psi as Dan suggested(10-12). What would cause it to open prematurely then?

Dan

Still Curious.
BlackJeep States:
Wastegate Appearance , Ok
10psi (approx) open, OK
Operation under presure, ok
Hard to rotate (spring force), ok.
Still don't work. But unplug it and Wala? I am curious. Maybe his gauge was actually reading 6psi instead of 10? A leak somewere?

Might be a stupid question. This was a curious thread for me. And it just stopped at the punch line.. hehe.. :)

Dan