I have an 01 F250 4x4 auto with gauges (stock tune) muffler delete which is having low boost problems. Crusing around and city type accelerations the boost gauge reads 0 psi to maybe 3 psi, WOT I can only get about 10 psi, maybe 11. Before with this truck I know I could get more then 15 or so. I have to give it about 1/2 to 3/4 throttle before I see boost readings on my gauge. I have verified that my boost gauge (autometer) is working correctly and the line has no leaks (so, unfortunatelly i think there is really a problem vs. just a leaking line to gauge). I have checked all up pipes and all intercooler pipes and rubber boots and snuged up all clamps. The SES light is not on nor has it ever come on. Using my diablo programer i can see that manifold gauge pressure is just about the same as the gauge is reading (however, the units seem to be wrong on the programer, that is another issue though). Turbine side of the turbo spins freely and has no slop in it. The EBPV is not closed because it is an unmistakable noise if it is closed (esp with straight pipes). Reading in FTE's posts and browsing through my factory service manual (unfortunatelly I dont have the powertrain diagnosing book yet) I see that the waste gate is a likely culprit. How does one go about testing this? Any tips or pointers?

 

Your wastegate is about the only other way to loose you boost if everything else is ok. Make sure your rod is still connected. You should be able to make up to 20lbs + with stock setting.

 

The rod is still connected. However, when i try to move it one way or the other, it is very stiff. I can only seem to move it towards the passenger side of the truck, and very little at that. It doesnt appear that its vacuum controled (dont know how vacuum could get to it), so how does it really work? I think by me knowing more about it will help with my diagnostics. How would i make sure the wastegate is shut and then drive to confirm boost is back?

 

The waistegate solenoid (Front of the Y) feeds pressure to the waistgate through the red line. The waistegate starts to open at 5psi and is fully open at 8 psi. This is not boost pressure it is the amount of pressure the Solenoid regulates.

 

Here's a neat product from dieselsite to check for boost leaks.


http://www.dieselsite.com/index.asp?...ROD&ProdID=607

If you can't wait to get one, you might be able to make one from some pvc pip or something.

Have you noticed higher EGT's? I would say that if you had high EGT's & low boost then you have a boost leak. If the EGT's haven't changed I would hunt the guage & connections down again.

 

If there is still tension on the wastegate rod, then you should at least have boost down low. Since you don't have anything registering under normal acceleration, I'm betting the wastegate is not the issue.

Since you have gauges, you need to let us know about your EGT's, as Buffalo mentioned.

I had a difficult time tracking down a boost leak earlier this summer. Tightening the clamps did nothing to help. Got tired of messing with it and ordered some new boots from Dieselsite. When I took all the OEM boots off, I found two of them that were cracked. Never would have seen it unless I pulled the boots off.

My 2 cents

 

Good point, I remember tightening the orange boots, tightening again, then again , then some more. Untill I finally took them off and found the problem was the boots themselves.

 

That is a prety neat tool. I just ordered it as well as a couple other things they had. In the mean time, ill pay some attention to EGT's and maybe order the troubleshooting manual i need

 

I too have a low boost condition. I started looking for replacement boots as recommended in this thread. I don't see dieselsite listed as a sponsor anymore. I went to their website and the kit costs 199. But the boots aren't made out of a silicon base as the cheaper one's are. Any of the sponsor's have the boot replacement kits?

 

If I remeber correctly, silicone based boots are not the best material unless you have done the CCV mod and got the oil out of the equation.

Here's a link to some boots. A friend in St. Louis is running 450+ hp on his 7.3L with these boots.

http://www.racepartsolutions.com/products.asp?cat=26

I went the less expensive route and used some marine diesel exhaust exhaust material from O'Riely's. I think it was about $25. On there for a year and running up to 28 lbs of boost. No problems - YET...

 

http://www.puredieselpower.com/catal...kit-p-496.html

 

the egt's dont seem to be higher then normal during driving today. I saw a max of 10 psi at one point gettin on it. I had my dad riding with me and he was looking at the diablo tuner and watching manifold pressure and he said he saw a max of 15 kpa (I think the units are messed on my tuner because it says 40 kph at 40 mph and says that the intake air temp is around 70C when its a mear 45F outside). So, if the units are messed up on my programer, then I can loosely assume that its 15 psi which is almost a max for a stock truck. Problem is, it only gets boost at higher rpm's and heavy accelerations. I guess ill wait for my tool to come and try to look for leaks.

 

Well, if your EGT's are not running high and you do not see any excess smoke coming out the exhaust then it does not seem that you have a boost leak from the boots. If you had a boost leak you would see higher EGT's & excess tailpipe smoke because of the fuel air mixter being too rich due to the lack of air. I know you have checked before but it really sounds like a pinch in the boost tube or the tubing is restricte somewhere and not reading correctly at the gauge. check the fittings around the boost tube T to make sure the fittings were not overtightened and restricting the air flow. But it might just be easier to wait for the boost leak gizmo from Dieselsite.


I have the predator programmer also, I do see a difference in temp from the air intake and OAT especially when driving around town. The engine compartment warms up quite a bit. The readings get closer to each other, within 5 degrees or so, after getting on the highway at 70 MPH. It's reading the data from the PCM so it should not be off. Also, you will probably notice a 10-15 degree difference in your aftermarket tranny temp guage and the programmers reading from the PCM. Not important just something else to point out since the sensors are located in two different areas of the tranny.

What are your EGT temps actually looking like?

 

I'd like to know also. If your boost and power is low, then:

High EGT's = not enough air.

Low EGT's = not enough fuel.

 

Just as an update, I got the boost leak tester from diesel site and I found a leak, drivers side of the "y" going to the drivers side intake manifold. Tried tightening up the clamp but didnt take care of the problem. I think the boot is cracked and I cant see it, bit I can feel and hear air leaking from there. I am now on a quest to find boots to replace the oem ones. I also did the CCV mod while I had the air filter and such off so I guess I can go with boots that arent as oil resistant. Any suggestions for boots? Oh, I just ordered this too this morning to make the job easier.