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turbo not spooling..?

22K views 13 replies 8 participants last post by  Caos56 
#1 ·
I am trying to diagnose an issue for my father in-law's semi-stock 96 7.3 Turbo 130,000mi. Initally there was a "no power" problem. To date I have done everything that I can think of that might have caused the problem. All new filters, "declawed the OEM cat" and ran straight 3 1/2" from headers back with high flow muffler. It has helped the power issue somewhat but I still am questioning if the turbo is working correctly.

I have read in several posts about the wastegate being the culprit, possibly stuck in the open position. I looked at it and noticed that it does not look stock. When accelerating you cannot hear the "turbo spool" until you are at least at 3/4 throttle, and even when it does spool I cannot feel it making any real difference in acceleration. Is this 3/4 throttle turbo lag typical with 7.3's? I am also wondering if the throttle adjustment to the pedal may be another place to suspect, it seems harsh/clunky in acceleration/deceleraing.

Any help would be appreciated as he has already dumped over $5,000 into trying to get this fixed with several mechanics. My thought was to open it up so that it could breathe and troubleshoot from there...
 
#2 ·
you ran the pipe from the manifolds of the down pipe? and the throttle is all eletrical so there is no adjustment usless the TPS is bad.
 
#3 ·
I am trying to diagnose an issue for my father in-law's semi-stock 96 7.3 Turbo 130,000mi. Initally there was a "no power" problem. To date I have done everything that I can think of that might have caused the problem. All new filters, "declawed the OEM cat" and ran straight 3 1/2" from headers back with high flow muffler. It has helped the power issue somewhat but I still am questioning if the turbo is working correctly.

Does the truck have gauges? What do you mean by running straight pipe from the manifolds back? do you mean from the downpipe coming off the charger back?

I have read in several posts about the wastegate being the culprit, possibly stuck in the open position. I looked at it and noticed that it does not look stock. When accelerating you cannot hear the "turbo spool" until you are at least at 3/4 throttle, and even when it does spool I cannot feel it making any real difference in acceleration. Is this 3/4 throttle turbo lag typical with 7.3's? I am also wondering if the throttle adjustment to the pedal may be another place to suspect, it seems harsh/clunky in acceleration/deceleraing.

The OBS trucks have no wastegate. If there's a wastegate on your truck, it's not a stock charger. When the charger spools depends on how hard you're driving it, and what altitude you're at. I would try looking for exhaust leaks around the up pipes. Look for black soot on the firewall.

Any help would be appreciated as he has already dumped over $5,000 into trying to get this fixed with several mechanics. My thought was to open it up so that it could breathe and troubleshoot from there...

Five thousand dollars and it's still not fixed and running perfectly? I'd be getting a lawyer and talking to these "mechanics."
Additions are in bold in the quoted post. I get the feeling that there's a drive pressure (exhaust) leak somewhere.
 
#5 ·
What you really need is a simple boost gauge to show how much boost. That
will answer many questions. There may be a boost leak.

When getting on the throttle is there any smoke? What color?
 
#10 ·
Someone must have put a 1.00 exhaust housing on it at some point, because the OBS never came with a wastegate.

Turbomaster makes a nice wastegate rod if you want to replace it. Hell, how would you even operate a wastegate on an OBS? it does not have the pramiters to do so...
 
#12 ·
A 1.00 housing on a OBS is really a good upgrade for 99% of people. Those little 90cc injectors will wake up with it.

But if the wastegate is not working correctly then all is for not.
 
#14 ·
I'd Bet it was converted to the early 99 set up, Can you post a pic or two of the engine compartment? I want to lookie on how they did it, does it have an intercooler also? and yeah, i love my 1.0 non waste gated housing!
 
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