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'87 740 T-Wagon "boggs down" when boost spools up

749 views 1 reply 2 participants last post by  manicman68 
#1 ·
This is my first post and all help/suggestions are greatly appreciated. I have a '87 740 T-Wagon with the t-05 turbo. When the engine rev's into Boost it sputters out, boggs down and looses boost/rpm; approx 3000 rpm in Park/Neutral or 1500 when in drive. It idles just fine, the pre-pump is operating and I've replaced it's sock filter and the main fuel pump is only 2 months old with a new filter. I've removed the turbo and there is no play but I'm not sure how easy it's supposed to spin. I can spin it easy enough but it immediately stops when I stop spinning it - not smooth but not rough either.

Upon removing the exhaust manifold I noticed the gasket is blown (1/8" tear) on the 4 cylinder (closest to the Fan) and the 3 & 4 exhaust ports are dirty while 1 & 2 are clean.

Also, before removing the turbo I removed the bolt that is just before the Cat Converter to see if it was the problem (my wife's PU Truck had similar symptoms a while back and it was the cat causing excessive back pressure) but it still acted the same.

I've ordered new gaskets and a new air hose (from airfilter to turbo) and when they arrive I'm going to use some heater hose to connect the turbo's oil and coolant lines to their out lines and try running it with out the turbo installed and see if it makes a difference under load.

Any other suggestions/experiences/ideas would be great!

Thanks in advance.
 
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#2 ·
Re: '87 740 T-Wagon "boggs down" when boost spools up (thomleidner)

I have the same problem, Except that when i get on the gas I also get a thick black smoke, And terrible gas milage.less then to the gallon. I am afraid to take it to the shop tp get it diagnosed(last time I had to replace the distributer and the coil and spark plug wires and it cost me $725.00)
I still haven't found the problem.
 
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