Not just worse but terrible.
Read codes
Originally had these codes 111 10 334 337 542
Checked the egr and noticed bad vac line and broke another so I replaced all the lines on the engine. TcEL came on.ook my time nice neat job. Found a cap on the tee degraded replaced it. Started it to make sure every thing OK. Hard to start and ran bad. Moved one line on canister to check if I had it wrong. Ran better. Checked EGR/EVP
Got 5 volts an plug. Checked the EVP for ohmns got 4200K ohmns. OK should be at 5K ohmns. Need to replace. Found nut loose on EGR tightened. Plugged it back in.
Started it. Ran worse!!! Looked around to see if I forgot to plug something up or knocked something loose. NO. Let it run to warm up as it ran got worse idle dropping sounding worse as it warmed up. Hmmmm... I removed the cap I put on the tee started running better. Hmmmm... Replaced cap while running made it run bad again. Noticed smoke coming from EDR. Didn't worry I put a little W-D 40 on bolts to make sure they were easy to move. Let it run. More smoke watched it get worse. Shut it down.
Read codes
Result 111 10 128 327 334 337 and 542.
Great 2 more codes!!!
Looked up new codes
128 - ( Truck Only ) Manifold absolute pressure sensor / vaccumn hose disconnected or damaged.
327 - EGR valve position circuit below minimum voltage.
334 - EGR closed voltage high
337 - EGR sensor circuit above maximum voltage
Correct me if I'm wrong but does this mean I need to replace EGR and EVP and manifold pressure sensor?
I am lost any and all help on this would be helpful!!!
It seems the more I fix the more problems I get.
Truck in Sig is what I'm working on..
Thanks
Charlie

 

I'd start by verifying your MAP sensor's vacuum line is still hooked up to the manifold. The 128 code is saying the MAP sensor signal is not changing, and the MAP sensor is integral to proper engine fueling.

 

Thanks ian .I had not thought of that I could have missed it when I checked over what I had been doing
I just am getting frustrated and need to slow down and recheck everything!!!
Thanks again .Sometimes ya just gotta be grounded and step back hold breathe .And start over.
Thanks
Charlie
I'll update soon

 

Thanks lead head!!!
You called it. Somehow I knocked it off ( vac line) and put that on helped out a lot
Cleared memory ran codes fixed the 334. Bad EVR sensor didn't ohmn out.
Tomorrow will run the KOER section cause all I got on scanner was 111 10 ,111.
Update after that.
I cleaned. The AIT/ ACT sensor figured why not 157 K and never been done so it's done now.
Well see what shows up . it's running better not great yet!
Thanks
Charlie

 

Keep us updated on how it goes

 

Alrighty then the update
New code test 112 and 334.
Replaced the EVP sensor still havethe 334. It did go away but now new one yihaaaa!
Replaced fuel pump etc. No more 542. Thank God!!!
Now have a rough idle does not want to stay running.
I do have a cel but when reved up will go away

But will run, if it dies, will start right back up.
When reved up runs smooth as silk sounds good too!
Gonna check timing and replace plugs and change oil.
Any ideas?
Ole Bessie is trying to kill me. I swear! Gotta figure this out before the 5th cause gotta move daughter home from college!
Thanks
Charlie

 

I see no mention of when the codes were displayed, i.e. KOEO tests or CM display. Any codes in CM (stored codes) will remain there for ~80 drive cycles until they clear. They can be manually cleared by pulling the jumper as the codes are being displayed.

As far as Code 112 is concerned, that can be triggered by not fully warming up the engine before running the KOEO or KOER tests.

 

No I fully warmed the engine up I took it for a good test drive before I ran tests. I also cleared all codes in CM before I ran them. I trying to clear the codes in KOEO before going to the KOER test. If possible.
I drove it tonight and it is got a rough idle it improves as it warms up but will occasionally stall out. I got brief display of CEL. I'm for a minute or so and then off.
So I will pull codes again tomorrow to see if it shows me something new.
I cleaned the IAC. Something is throwing the engine off normal running. What I'm not seeing YET!!
I will find it. Just gotta play with this and that.
It has never run like this before. So I'm in new territory for me with this motor.

I will be more clear as to when and under which test I see the code come up.
It is just driving me nuts cause I fix this and that pops up. And that seems to be totally different than what has been thrown before. All valid issues just nothing leading me down the path to resolution!!!!
Thanks for the input.
After I change plugs I hopefully will know more.
Thanks
Charlie

 

Hi,
Thanks for this, doing the same on my 89 F-150!

Putting in a new EGR Valve Monday and new vacumn lines as I go through the codes.

Was going to just clean EGR but it was toast!

 

Multiple sensor codes like that would lead me to believe an issue with VREF from the PCM. Have you pulled the computer out and inspected it for signs of leaking capacitors?

 

Thanks Seagiant hope I help you thru my misery!!! LOL!
Rla2005 I been thinking that all day long. I've just been avoiding it by trying to find something stupid thanks staring me right in the eye?
Ran KOER but results were funky so I'm gonna repeat but with help. Did test some othermthings tho.
Changed plugs one cyl had a slight ash build up. But great improvement in idle quality and sound!!
MAP sensor test
5 .04 vac.
12 54 vdc.
154 Hz at 0 in Hg.
100.9 Hz at 20 in Hg.
Checked grounds have one to repair frame to body. But jumpered it when I ran tests. Made sure of the vac lines I am gonna replace the MAP line but ran out of vac line. I had bought all that O'Reillys had the other day.
Any other suggestions before I pull PCM. I'll do them first then try running KOER one last time and see what I get before pulling it!!!
Just trying to rule out as many possibles before I pull PCM.
Thanks
Charlie

 

Hi,
I cleaned all the plugs on the sensors all over the engine.

Replacing old vacumn lines.

I pulled the vacumn resivor (tomato can) and looked for pin holes and then sanded and painted it.

Just things you don't usually have time for.

New EGR Valve goes in tomorrow.

Also ordered new thermostat housing elbow that holds water temp sensor.

Hope after all this makes some codes dissappear.

May have problem with MY PMC also????

Thanks, everyone, learning here also!

 

Well that is how you keep things working. Fix as you find em. By keeping on top of things before they become a problem.
That's why I'm doing what I have been for the past year. As stuff breaks wears out I fix / replace / repair things as they happen. I try to stay ahead of the game but.... It can keep ya hopping.
I look at what I've spent over the last year. It works out to be around $10.00per month since I bought the truck. During that time I didn't have to spend that money. Now I'm just spending for the future. When I bought the truck in May of 1996, I had been looking for a truck with the specifics I wanted. It took me a little over a year to find her.only thing I didn't get was the color I wanted. But I was and still okay with the color I have. People try to buy my truck all the time. Even if I have to put another 10 k into her I cannot buy anything close to what I have for less than 50 to 60k. I still won't have that much in the truck including purchase and all the repairs that I have done!
And I will have a truck that can do whatever I need it to do and more!!!
So later this morning I'm pulling the PCM and gonna look at it. If I find problems I'll replace or repair as needed. Get something nice and keep it that way. It will always be there when you need it!!!
Take care of it and it will take care of you!!
Thanks
Charlie

 

Okay,
As you can see PCM looks pristine!
Now where to go? What should I do now???

I was sure I would find a probllem. But I don't see any issues.
Just quick recap
Can pull KOEO codes. Can pull CM. I can erase codes. But when I try to run KOER I either get different codes each time the only constant code is 334. Each time I get those codes I check the indicated part and most times part is in specs.

Does this mean that the PCM is suspect or do I have a bad code reader?
Or does it mean I have something that is affecting the idle that does not throw a code? If so what to check now?

Please answer as soon as possible!! I really need to get this fixed so I can road test before my long trip!!!

 

I can't say that the PCM looks pristine.

The pics are to dark and there is fuzziness that distorts.

Try to post lightened, clearer pics of the board.

You are looking for 1 to 3 Capacitors on the board. They are usually blue.

Look very closely at the leads where they enter the board and for ANY discoloration. If the board is GREEN and there is a brown stain around the leads, then there's your culprit.

These Capacitors have long out lived there lifespan. You should have them replaced when possible to completely rule them out of the equation.

Another thought is a the alternator isnt charging well and if the voltage drops just below 12.5, then that can also cause erroneous codes and different codes to pop up as different sensors react differently to voltage dips.

But focus on the PCM board.

Try monitoring the 5 volt reference line from either the TPS or another sensor that uses the 5 volt reference line.