power loss at speed, rough idle, and acceleration bogging

[droolmonkey]

did a search, but found little info

so my 97 ex ohv is starting up cold and running at idle well till warm, then rough idles between say 600 and 1000 cycling every second or so, then on acceleration, it runs very rough till about 1700 rpm and then loses power after 55 mph but only under load (climbing a hill). and it throws codes. ...last i checked it was po171 and 174 but at different times. never the at the same time

iac is good, maf is good, air filter is clean. ..tomorrow im going to check fuel pressure, and replace the fuel filter.

spark is good on all 6. new plugs and wires. ..and i am borrowing a compression gauge tomorrow as well.

any ideas that could lead to the symptoms?

 

[droolmonkey]

changed the plugs and wires, couldnt do a compression test as i couldnt get the tester today

i did get the codes read though

po171
po174
missfire cylinder 2
missfire cylinder 4
missfire cylinder 6
2 o2 sensors are throwing codes

the #2 plug wa extremely fouled with oil/gunk

the new wires and plugs helped smooth it out a bit, but it is still rough, loosing power under load and bogging during low speed (0-35) accleration.


please anyone have ideas?

 

[ragajungle]

Fuel Pump? maybe put a new fuel filter in? couldnt hurt...

 

[saewoody]

Do I recall correctly if those are the running lean codes? If that is the case I think it is related to the intake manifold gaskets (at least on the SOHC). Someone please correct me if I am wrong. Good luck.