help to diagnose a sick r model

[motts]

Hi, ya'll i have a 1987 rss 688lst with a E6 4 valve well it starts and runs it just don't seem to make any power no black smoke slow to rev and build boost it has new fuel filters and a lift pump where do ya'll suggest i should start troubleshootin this thing i don't much know how on these here things any help would be greatly apprieciated

Thank you

[motts]

mine has the anerobic selenoid with a new diagphram and the truck has also been run with it removed and no differance as stated in early posts  so more than likely i am down to the pump or gov  is there any way to check the rack travel with it mounted on the engine and can these things be re timed by using air in the  static pressure test method?  going to run it on a bucket of fuel just to eliminate the supply system what kind of flow should i see out of the return line? as i still can not find any info on the fuel overflow valve.

Thanks

[siding guy]

This is a long shot, but years ago I had one with similar symptoms that had a cracked intake manifold. It was cracked on the bottom side and could only be seen with small mirror .

[thomastractorsvc]

The puff limiter set up has avalve located on the manafold and a air valve located on the front pump.  Follow the air line.  The valve located on the end of the pump is what needs to be removed as it holds the rack from opening and needs to be shimmed properly.  It may be stuck open or not shimmed properly.  That will prevent the rack from opening and will not allow boost to build.