Topic: V6 help!!!!

[toy85ota]

I pick up an 1990 V6 for $500. Its runs, but runs like crap. Did a compression test and the middle cylinder on passenger side had hardly any compression about 5. And the middle cylinder on driver side had only 75, all the rest were good at around 150. Whats the problem, values??? Any help would be appreciated!

[Snowtoy]

The 3.0 is prone to burnt/stuck exhaust valves, but usually the #5 or #6 valves not the #2 or #3 ones.  You could start by reshimming the valves, this is a PITA, you will need to determine the size that is needed and get them from the dealer, may have to order them. 

Have you done a leak down test?  This should be done before bothering with shimming the valves.

If you are not that familiar with diagnosing problems, you might take it to the dealer and let them diagnos what the problem is then fioxit yourself.  The PO was probably told either the HG was bad or it had burnt valves and didn't want to spend the $2k for the shop to fix it.  If the valves or the HG are gone, you can rebuild it yourself for under $1k.  Thgis is what I did after the second burnt valve in less than 6yrs was diagnosed.  I took the heads to a shop to be rebuilt, installed headers, new exhaust, replaced all of the sensors, rebuilkt the injectors etc for about $1500.  The headers and exhasut ran about $700, so had not done that it would have been around $800 for the complete rebuild.  If yoiu are looking for a factory service manual, there is a link to one here http://personal.utulsa.edu/~nathan-buchanan/93fsm/.  It is for a '93, but will work for the '90, the manual also has the 22re.

[BLACKDOG]

Could be the valves, or the pistons, or headgaskets.  When I blew my head gasket on the driver's side, only one cylinder was low.  Did you check for the symptoms of a blowing a headgasket?  Also, you can get an idea of whether it is valves or pistons by doing a dry compression check (which you did) and then doing a wet one.  Add a small amount of oil to each cylinder, and then crank the motor.  If the compression goes up, you're looking at a worn piston rings.  If the compression doesn't change, is more likely valves or the HG.  A leak down test would definitely be a good idea, but this might be a good place to start.