No Boost! HUH??
#1
No Boost! HUH??
Ok, so let me long-windedly explain what's going on and what I've already determined, and maybe y'all can make some suggestions.
This is my first powerstroke. Bought it three weeks ago. (Chris and the gang were very helpful, by the way. THANKS, GUYS!!) 2001 F250 6-speed. Had a terrible miss. Turned out to be a shorted UVCH. Got that fixed. The truck gets around, but it's weak, and sounds like its detonating under load. Also smokes a little. On Chris' suggestion, I pulled both valve covers and torqued the injectors, rockers, and glow plugs. 800 miles back it got 15 quarts of Rotella 15w40, Motorcraft FL1995 oil filter, Wix fuel filter, and the left UVCH. The oil is still somewhat clear, and it has used maybe a quart in 800 miles. I've blown out the EBP sensor tube, checked the sensor for plugging (it's not pristine, but I can see all the way to the diaphragm), and I've unhooked the red line from the wastegate actuator. I pulled the turbo inlet tube and checked for free rotation, slop, and endplay. This all looked good. I started the engine and could see the c-wheel rotating at idle. (I only ran it a few seconds) I was bothered that I could NEVER hear the turbo, so today I got a tee and some 1/4" fuel hose and teed a 0-30 psi gauge into the MAP sensor hose and put the gauge on the seat and drove home. At 60 in OD I saw ~2 psi on the manifold. This tells me why the engine is weak and why it smokes a little, but now I've got a bigger mystery: If the turbo rotates freely, where's my boost?
Any thoughts?
This is my first powerstroke. Bought it three weeks ago. (Chris and the gang were very helpful, by the way. THANKS, GUYS!!) 2001 F250 6-speed. Had a terrible miss. Turned out to be a shorted UVCH. Got that fixed. The truck gets around, but it's weak, and sounds like its detonating under load. Also smokes a little. On Chris' suggestion, I pulled both valve covers and torqued the injectors, rockers, and glow plugs. 800 miles back it got 15 quarts of Rotella 15w40, Motorcraft FL1995 oil filter, Wix fuel filter, and the left UVCH. The oil is still somewhat clear, and it has used maybe a quart in 800 miles. I've blown out the EBP sensor tube, checked the sensor for plugging (it's not pristine, but I can see all the way to the diaphragm), and I've unhooked the red line from the wastegate actuator. I pulled the turbo inlet tube and checked for free rotation, slop, and endplay. This all looked good. I started the engine and could see the c-wheel rotating at idle. (I only ran it a few seconds) I was bothered that I could NEVER hear the turbo, so today I got a tee and some 1/4" fuel hose and teed a 0-30 psi gauge into the MAP sensor hose and put the gauge on the seat and drove home. At 60 in OD I saw ~2 psi on the manifold. This tells me why the engine is weak and why it smokes a little, but now I've got a bigger mystery: If the turbo rotates freely, where's my boost?
Any thoughts?
#3
Boost sounds about right at 60mph just driving along in my opinion. Only real way to get boost is under a load, boost is actually the pressure built up behind the intake at the compressor compresses it, when freely flowing at little or no load all air(boost) is essentially being used by the engine. Without a wicked wheel, the turbos aren't really loud.
#5
I agree that your current boost psi sounds normal. DO a search on here for boost leak detector and you can build one of those to confirm you dont have any boost leaks but its possible that what you're feeling is just the plain old 7.3 sluggishness. I had to drive without my chip for a couple weeks and it was killing me.
#6
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#9
Here's a link to the in-tank mods:
Welcome to guzzle's In-tank Hutch Mod Web Page
As far as the fuel pressure, the best place to put a gauge is on the fuel bowl. If you do a search on here for fuel pressure gauge, or fuel psi, you will probably find some pics.
Welcome to guzzle's In-tank Hutch Mod Web Page
As far as the fuel pressure, the best place to put a gauge is on the fuel bowl. If you do a search on here for fuel pressure gauge, or fuel psi, you will probably find some pics.
#11
Thanks, fellas. I looked at the mod. seems pretty straightforward, but will have to wait til I have time to accomplish it. The fuel pressure check sounds straightforward as well. I'll post the results in a couple of days. Is it possible the "detonation" sound I keep hearing is the 'cackle' I see referred to? If so, what causes it? On the way to work this morning with the cruise set at 65, I watched the 'boost gauge' and sure enough, coming up a hill, it climbed toward 5psi. It's a good day when you learn something new!
#12
Could be cackle, the problem is that the fuel rails are dead headed. It can be completely eliminated by crossing over the fuel rails, either with a regulated return or Clays convenient FRx
Riffraff Diesel: Fuel Rail Crossover™
Riffraff Diesel: Fuel Rail Crossover™
#13
I had crazy-loud noise coming out of the front of the truck when I first bought mine. My exhaust system between the block and the turbo might as well have had screen doors for all the backpressure I was building. I had leaks in both manifolds, the up pipe, and the collector - I'd be looking for soot around the pre-turbo exhaust system. My entire exhaust system is now new and I can finally hear the back over the front when the passenger window is down. I also added the Riffraff FRx to work the air bubbles out of the fuel rail. My truck doesn't freak out if I get below 1/4 tank, so maybe the hutch mod was already done - I dunno.
Everything in my signature is a link... that last one is pretty handy.
Everything in my signature is a link... that last one is pretty handy.
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Chris56ford
1994.5 - 1997 7.3L Power Stroke Diesel
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07-20-2014 09:15 PM