Runnin' rich!!!!

[shonuff]

Hey everyone. I have a 94 ranger 4wd 4.0l that has been running rich lately. It feels a little doggy when driving but not super bad. After running for a while if I shut it down and then start it back up it develops a miss that goes away soon after I start driving. I pulled the plugs and the #4 plug threads are wet. Just the threads by the way, the tip is dry but is brown and crusty. I had the ign mod tested and that seems fine. Tested the coil packs and they were pretty consistent. Also, after it warms up a while i get a strong fuel smell but cant find any visible leaks. I just put a new plug in #4 cly. and it seems to start a little better. Tell me where to start, this thing is costing me a fortune in gas. lol. I have a picture of the plug but for the life of me cant figure out how to post it.

 

[shonuff]

something I forgot to mention. I did NOT have a check engine light but went and got the codes pulled. They only did the koeo test and got a 0176 code. Now if you guys think that a new o2 sensor will fix my problems I'll go get it. But I think its something else. I also haven't found any vacuum leaks.

 

[Maniak]

Check your fuel pressure. If the diaphragm ruptures it will suck fuel into the vacuum line.

The other option is the spring in the Fuel pressure regulator goes bad and the pressure goes way up. After we rebuilt our explorer motor it ran funny and rich. After a 20 mile drive it would lope at idle with no CEL. I finally noticed black smoke out the tail pipe and checked the fuel pressure. It was running 60-70psi which is double what it should be.

~Mark

 

[shonuff]

Yeah, I wanted to check that today but they said it was $150 rental. I will find a way though. I will post back when I get it checked. Thanks Mark.

 

[Maniak]

Assuming you have a harbor freight near ya...

For $20 you can get this.

http://www.harborfreight.com/fuel-injection-pump-tester-92699.html

~Mark

 

[shonuff]

Didn't even think about harbor freight. I shall pay them a visit tomorrow. Thanks again!

 

[shonuff]

Ok, I know its been a bit but i finally got around to checking the fuel pressure and it was right at 30psi while running. After i shut it down the fuel pressure dropped to 0psi. Is that normal?