Code 173, totally stumped.

[AGodlyCanuck]

1992 explorer.

Code 173 running rich bank 1
Cleaned MAF, checked plugs, wires, distributor pack and replaced o2 sensor.

Runs better but the code persists after cleared.
Comes on and off randomly on highway.

Pretty stumped here.

 

[AGodlyCanuck]

Gonna add code 565 canister purge fault to that as well. Got no clue.

 

[AGodlyCanuck]

Come on guys, really need help with this one.

 

[BrooklynBay]

Check the fuel pressure with a test gauge then monitor it after the engine is off. Maybe you have a leaking fuel injector or an issue with the fuel pressure regulator.

 

[smegun]

relay … and fuse 18 inside …. had similar dtcs changed relays rock auto cheap right now

motocraft soak (attachment ) the purge valve hose goes into the throttle body ...I have replaced the hard vinyl line with silicon but was running it backwards for a short time evidently duh arrow twards (engine throttle manifold) duh :/ there is about 10 percent of fumes going back to the throttle body makes a diff …. run seafoam I ran some berrymans calls for motocraft pm-3 … had disconnected the o2 sensors temporarily to get running without too much back talk my truck sat a long time has similar errors as above probly leak of an injector had 14 of those injector cans on rebuild more than half tested bad as in no click I left them in cleaner too long the others were newer but referbs i got one that is bad evidently and have similar 173 error I bought some new injectors so ill post again if all goes well relays got me running better the hot soak helps also ..

 

[AGodlyCanuck]

One thing I discovered is that if I'm driving and the code comes on. If I slow down 10km after 20ish seconds the code will go away.

 

[BrooklynBay]

The TPS is telling the computer that you need more fuel to accelerate. The air/fuel mixture will increase, and also add to the issue of a rich fuel mixture. Check the TPS with an Ohmmeter.

 

[AGodlyCanuck]

I will definitely try that. Ill have to try and find a guide on youtube on how to do that though lol

 

[AGodlyCanuck]

I also noticed that my drivers rear brake may be dragging ever so slightly... Is it possible that the extra drag from the brakes could be causing it to work slightly harder and causing the rich condition?

 

[AGodlyCanuck]

So "fully closed" is .86 and WOT is 4.60

So I'm guessing that's fine.

 

[Turdle]

Yes that sounds good to me.

I have a hunch that there is either an injector stuck open, or, there is a wire short circuit causing an injector to be held open when the engine is running, or possibly being commanded to stay open due to a faulty ECM.

I have seen on this forum quite a few times, faulty capacitors on the ECM circuit board causing all sorts of fuel delivery issues. I think the capacitors can be replaced if you have soldering skills. You might crack the ecm open and take a look.

After this, see if you can rent, borrow , buy a noid light tester for the injectors. They make a type which hooks in line with the injector, you would be able to visually observe an injection pulse which was stuck "on" as the noid light would glow steadily.

 

[smegun]

i got a 173 and a 137 tonight after a 40 mile trip farthest ive gone since head job I just put new injectors in

so its like I didn't put injectors in :/ anyway im out of thinkers like I beeped the harness back to the main harness all the injector + positives are continuous and all the - negatives beep back to the harness connector fine so the top harness is good I even have two pcms identicle one with less miles but both were giving me the 172 173 before ...I was all over the cam sensor before and im still not exactly sure I got the procedure right there may be developed slack and im not making a window Ive had others tell me the cam sensor is only important at start up but I question the behavior as not making a window and wondering if I got a bad component or two in the pcm

would like a list of the electronics to replace I would change the caps but I got a brain with less than 50k on it I want to think its a driver shorted like I could solder in one I think dam I had a pcm in my hand at the junk yard today but didn't buy it because it was for a non egr motor