94 XLT Loading up and engine RPMs slow.

[Rj_TailSpin]

First of all... this forum is great! Years ago, with the help of this forum, I was able to fix problems that Ford couldn't. My gas mileage increased dramatically and my Expo has ran perfectly for a number of years.

1) In the last few weeks... I noticed my water temperature gauge starting to raise and then fall back to mid-way. I topped off the Antifreeze and it seemed to be more stable.

2) Also during this period, my perfect on the first try starting engine developed a problem where it would act like a flooded 1969 302hp (if that makes sense). Not every time though...

3) Yesterday, the engine light came on and it started running rough like it was loading up. I could smell the gas puking out the back and the RPMs started ramping lower until the engine almost quits.

I used my code reader and initially got all kinds of odd codes. I guess it's a learning curve when trying to count again-grin. Well, I did manage to repeat the same codes twice. 192 and 176 (both O2 sensors are reporting a lean condition).

I will be doing more testing this morning.
I find it hard to believe that both O2 sensors could go bad at the same time. I figure there's more to it. Any inputs?

Thanks
Robert Lehman

 

[Opera House]

Yea, shoot the messanger

Think you mean 172 & 176. If the O2 sensors tell you something, keep replacing them till you get what you want to hear. Sounds like the real problem is a vacuum leak, faulty fuel pressure regulator, pump or something else which is causing the mixture to be lean. Even if you unplugged the O2 sensors, that would not prevent the engine from starting or running pretty good.

 

[Rj_TailSpin]

Yeap, your right on the codes.

I reset the puter by disconnecting the battery. Ran the engine, put in drive etc... for long time. Engine light never came back on. No codes were found. The engine was running warm.

I ran it for 15 minutes and tested the codes again... nothing.

Is it possible I got some bad gas? Or, something is going South, but only have way there???

I drove it and everything seemed to work okay. I did spray a bit of carb cleaner in the throttle body. I guess I will have to wait until it acts up again. Problem is... I don't trust it for highway driving.

Thanks
Rob

 

[Techmonster]

as far as the bad gas thing my 94 did something very similar when i got a bad tank of gas once. It started the same way(kinda like the 68 302) It would run on the highway and lose power and gain back and rpm's would be crazing engine lights would come one and go. I'm not saying this is your problem, just happend to me too and sounds similar. There really isn't much to do about bad gas either except trying to dilute it with good gas and run the old stuff out.

 

[Billy177]

sounds like a bad fuel pressure regulator. pull the vac line off if it if there is fuel in it you have found your prolblem

 

[Rj_TailSpin]

I removed the vacuum hose from the fuel pressure regulator and it looked dry. I ran the engine, shut it off and check it again... it was dry.

I have driven the car 30 miles since I cleared the codes. Everything appears to be working now. The engine does get warmer than normal and it misses slightly once in a while at an idle. Might be time to replace the plugs again.

All the original codes I found relate to a "lean" condition. Needle in a hay stack! Just about anything can cause a lean condition!

Any more ideas?
Thanks
Robert