I just did a major engine valley re-seal of all the fuel fittings, new mechanical lift pump, swapped in a low mileage turbo w/wicket wheel, added an intercooler. I fired it up a few days ago, now I'm finishing my 3 gauge install, tested yesterday and boost gauge isn't moving. The boost tube hoses are not puffing out while I rev it up. I temporarily plumbed the gauge directly to the Tee fitting at the passenger side manifold, still nothing. I put my finger over the open 1/8-NPT port, nothing. It's hard to tell if any connections are leaking with the mechanical fan moving air.

Details:
1995 E350 van w/7.3, 190k miles, I took it apart to fix the valley leaks, fuel bowl o-rings, fuel lines, fuel pump leaks. I found a damaged turbo impeller while it was apart (the intake hose popped off a year ago while I was getting it unstuck from a dry lake bed, the cloud of silt must have damaged the impeller at that time). The van had been down on power, I'm now sure that was the impeller issue. I recently added an intercooler as well, big job, fabricated my own tubes, mounts, I used an e99 7.3 spider, pressure tested all the tubes and the used intercooler, holds tight to 40psi. I rebuilt the turbo with lightly used parts from Craig'sList. I used a combination of new and used Ford blue boost tube couplers, good clamps, added rolled beads to all of the tubes I built end's, to prevent leaks or blow offs, made sure everything was square and factory-like fitting. Definitely NOT a hack job.

Here's what I know:
It starts fine, idles well, but I have no boost at idle, no boost when I rev it up in the driveway (not moving)
I removed the new boost gauge tube and put my finger over it, very little if any pressure escaping.

Before the major changes, the van was down on power, I found bent and dog eared impeller vanes. I found a local guy who had upgraded his OBS truck with an aftermarket turbo, he sold me his recently rebuilt and balanced center section w/billet wicked wheel. I bolted it into my exhaust housing and used my impeller housing I think. I saw his receipts for the turbo work, all looked legit. Could I have mixed and matched parts and created an inefficient no-boost Frankenstein's monster turbo?

Do I remove the mechanical fan, and better check for leaks? It's a super cramped engine bay, but at least the turbo is easy to get to, from inside the van, seats removed.

I need some trouble shooting help...

 

If its holding 40psi then you don't have a boost leak. My guess is that your gauge is defective, and tje low power might be pre turbo exhaust leak such as your up pipes, exhaust manifold, or collector gasket. You can check for exhaust leaks if you own a leaf blower or have a boot that fits on your current exhaust pipe, just pressurize the exhaust and have a spray botttle with water/soap solution and spray away.

 

I didn't do a very good job of explaining my situation:
The tubes I fabricated, the intercooler I used, all bench tested together to 40psi. The spider, turbo, intake manifolds were not part of the test. I don't have a good way to test it all on the van.
The new Autometer 0-35psi boost gauge bench tested 'good' this morning against 30psi regulated pressure from my compressor, so unfortunately it's not a bad gauge.

Remove the fan and test joints with windex?

I'm trying to logically imagine the possibilities that would give me a 'no boost' condition. It was down on power before, I had no gauge nor did I check. No dead cylinders of engine misfires...

Could I have fubar'ed the turbo rebuild? Maybe the used parts were mis-matched, too small a turbine wheel and too big of housing?

 

Have you driven it yet? It’s hard to get real numbers without it being under load. Run it down the road and see what you get

 

Have you driven the van since the repairs, or are you just reving the motor in the driveway? You will not see any boost just free reving the engine. Take it for a drive and push it a little. If there is a hilly road in your area, take it there and make it work. Heat and making the engine work will make the boost.

 

Aaah... I’ll bolt a seat back in and drive it, and report back.

 

I think you need to pressure test the system installed in the van. I made a simple boost tester out of 4" PVC fittings that I clamp in place in the intake tube instead of the filter elbow and pressurize the whole system. It's easy to miss a misaligned boot or bad connection while your slipping it all together. It could also be the little o-ring on the V band seal between the collector and the turbo outlet - that one can be a bugger to keep in place while you're putting it all together. I just clamp this in place, install teh air hose (regulated to whatever pressure I want) and pressure the system up. You'll leak some air through the motor (open valves, etc) but it will build pressure so that you can spray soapy water onto the fittings and connections and see if you have a leak.




As for boost numbers, you won't see anything at idle, and little to nothing while you're free revving it up in the driveway. You kinda need to have a load on it to build boost, so who knows, it may also be that there is nothing wrong.

One other possibility that hasn't been mentioned is that it could be the little plastic tubing to the boost gauge. That stuff is notoriously crap-tastic and it's easy to kink or crack it so that it won't indicate pressure to the gauge.

 

It took a few more full work days to finish the gauge pod install, instrument lights on a dimmer, put the dash back together (repair some of the brittle plastic pins I broke) , seats in, finish trimming the grill, repairing the cracked headlight support, and 32 other little things, so I could finally road test it yesterday afternoon.

Yep, it's got boost. As much as 15psi at higher rpms. That's a relief. Thanks to the several who responded for the direction on this, you were spot-on.

Funny thing is, I was helping a friend shake down his new turbocharged drag car 6yrs ago, and we had the same thing... no boost in the shop, didn't even move the gauge a little, until we put a load on it. Me driving, about the time I put it in 3rd gear on it's maiden 1/4 mile pass, 25psi and pushed me back in the seat. I feel like such a dope, I should have remembered that, DOH!

I was surprised at the fast response time of the Autometer EGT gauge (it's the newer stepper motor type, probe in the exhaust manifold) When I romp on it, the new gauge climbs fast, from 400f to 1100f in maybe 60 seconds. I left the dog house cover off (van) so I could check for valley leaks, and almost burned my shin from the blistering radiant heat off the manifold. That mechanical clutched fan moves some air, too!

A brake caliper is hung up, and started smoking, ending my short test after just 5 miles. It had been intermittently do this last year, sitting 8 months didn't help. I'll get that repaired and take it out again, but going racing this weekend, so there's that.

I still want to shoot hot and cold side boost tubes with my IR temp gun, and see the effects of the intercooler addition, see if 'the juice was worth the squeeze' so to speak...

Thanks all for the encouragement

 

Heck yes, glad you are getting along on this. Very cool proper hot rodding project.

 

This is great to hear. I'm happy it's running well. I've always thought a 4x4 diesel van would be a cool project.

 

Any diesel van with hood stack!!! Yes!