Okay ive been trying to fix this problem forever and i keep narrowing it down and crossing things off the list. It runs good for about a half hour then it starts losing power. And i hear a wining sound almost like power stearing whine but its constant with accelorations. Another thing i may have a exhaust leak right under the oil pan. I can hear it rattling and there is a o2 sensor after it. If there is a leak before the sensor maby it could be throwing it off. I pulled the pluggs (which are brand new ) and their pretty white. Ehich i think means its burning hot. Ive sprayed the motor down with carb cleaner and no change in idle so i dobt have a gasket leak. Any suggestions? Or am i on the right track with maby leaking exhaust? im out of options. ... Any brainstorm on ideas would help

 

Leak in exhaust ahead of O2 sensor can cause problems.

Some additional O2 may enter the system when exhaust pressure drops below ambient (very briefly) and the exhaust leak causes bias problems because O2 sensor is providing oxygen content measurement relative to outside ambient air. If ambient air has significant exhaust it will have lower O2 content.

Suggest fixing the exhaust leak. Probably a cracked header or bad gasket. It's not difficult to remove, if the bolts are too bad.

good luck

 

Brainstorming: Valve clearances in spec? EGR ports clean?

 

It seems to be related to weather also. Its affecting my idle as well. The headers are good. I cant tell if its leaking under neith the oil pan or not cause its so close to the pan. Someone bent it up into the pan and the paint is burned off where its touching the pan. Its a flat rectangled piece of exhaust. Its on the piece after headers but before the cat convertor and theres a o2 sensor before the cat. How can i fix it without buying a new piece. Cause its weird shape and my headers are split into 2 the whole way to that piece

 

Cleaned the entire egr system. New valve new silinoud and cleaned the ports. But valve clearance intesests me how hard is it to do that?

 

Valve adjustments are not difficult, but are unlikely to cause poor running. If they are loose, the result is some valve train clattering.

I've checked my 94 EX periodically and found them to be w/i spec at 245K miles. I did have a cylinder head rebuild some time back where valve train was rebuilt and I did adjust them carefully before installation.

good luck

 

My thought was exhaust valve clearance at or close to zero, the engine heats up, the valve(s) stay open a touch, and runs poorly.

I've never experienced this problem on my Accord but it is common on four-cylinder CRVs, to the point of burnt exhaust valves. @230K, on the first valve adjustment I did (and probably the first ever) on my Accord, I found several exhaust valves at less than four thousands inch clearance. It wouldn't hurt to check. Eric the Car Guy has a video on youtube. If you use go/no go feeler gauges instead of the "slight drag" method as the video shows then it's even easier to do.

Another brainstorm: ECT resistance too high? How's the gas mileage?

 

Gas milage is normal. It happens on long trips over half an hour. It feels like a dog and loses power and accel. My temp gauge runs where it normally does. Ive replaced alternator, plugs,wires, distributor, egr valve, egr silinoid, cleaned egr ports, cleaned iacv, cleaned fitv, bled the cooling system, nrw cat convertor, added cold air intake, and none if this fixed it i bought a vaccume gauge but am unsure how to test for vaccume leaks besides spraying carb cleaner on everything. But no luck still running like **** after half hour and it idles crazy low too (ive tried adjusting idle) but the idle is never consistand somedays it idles high then other days it idles really low. Then today when i parked it was looping from 1500 to 1200. This is my second iacv both were used but off cars with about 50k so im lost. The idle acts up when its running bad so i think their connected some how

 

If you haven't cleaned the EGR manifold, you should do so.

Unequal EG distribution could cause missing; too much EG in one port due to others blocked causing a lean miss. Pretty easy job, but you will need new injector/fuel rail orings. They will be old/brittle if this has never been done.

good luck

 

I cleaned that already and put new o rings on the injectors. Im out of options