lurches mostly 3rd gear... no codes

[Tiha]

I worry about the "thing" next to cyl 4 .. both cyl 3 and 4 have had a history of burning up spark plug wires.. like it gets real hot there.. missing a heat shield or something? not having a good running EGR I think can make the exhaust run hot I think I have heard that... ???

I have always done EGR delete on pretty much every vehicle ever and never had an issue with it running hotter or burning up wires.

Running hotter means running leaner usually. Maybe an injector issue back there? But I gotta say as many times as people have blamed injectors It is extremely rare that injectors were the issue.

 

[L\Bronco]

I can do that... wasn't thinking related to code 44 stuff... but I will check everything at this point. just check it.... right around 37 to 38... revving it jumps to 39,, decel drops to 36.. mostly hangs around 37.5 to 38

That's great, is that fuel pressure while it's acting up? That's the number we need to see.
I may have missed it, but, did you try running it with the EGR vac line removed and capped?


The code 44 references an issue with the air injection system, While it may be contributing to your hot exh manifold, it is post combustion and rarely causes drivability issues.

Good luck
Cheers

 

[DWilliamA]

Smack your TAB & TAD solenoids smartly a few times with a screwdriver handle.
(Not kidding. They can get stuck after setting a while)
Then run your KOER self test again and see what happens.

wondering if I could even spray some sort of cleaner into the vacuum in port, even starter fluid maybe ... will try the "smart handle" technique

 

[DWilliamA]

That's great, is that fuel pressure while it's acting up? That's the number we need to see.
I may have missed it, but, did you try running it with the EGR vac line removed and capped?


The code 44 references an issue with the air injection system, While it may be contributing to your hot exh manifold, it is post combustion and rarely causes drivability issues.

Good luck
Cheers

yes... that is fuel pressure engine fully warm and running bad

I have not tried running it with the EGR vac off/plugged.... will do shortly

 

[Motech]

wondering if I could even spray some sort of cleaner into the vacuum in port, even starter fluid maybe ... will try the "smart handle" technique

Ya, chemical repairs are rarely effective.

I have restored air injection and EGR performance with the whackit technique many times to get those trucks through the smog test. (shhh...)

 

[Motech]

it does pull a small vacuum at idle at the EGR

EEC IV EGR solenoids will pass a little vacuum when closed, like maybe 2 inHg. The EGR valve itself is calibrated to not begin to open until it gets about 4 inHg applied.

If you are getting 2 inHg to the valve at idle, and it is hanging up open a little bit, then you've got a defective EGR valve.

On the other hand, if you are getting too much vacuum to the EGR valve at idle, you may be suffering from a plugged up orifice port or filter in the top of the EVR solenoid. The black plastic cap can be pride off with your fingers, and inside you'll find a foam filter and a vacuum port. That port will constantly be bleeding vacuum off, so if it gets plugged or if the filter is all mucked up, that will Force vacuum back out of the solenoid and over to the EGR valve.

 

[DWilliamA]

Have not unplugged vac to EGR and capped it test run... the EGR is getting variable vacuum... no or little vacuum at idle and more as you increase rpms.. EGR and solenoid are new.

The TAB/TAD and TAD/TAB Diverter are all getting good vacuum

The TAD solenoid does nothing... banged on it.. sprayed a little WD40 in it... when the truck is running you can blow right through it at idle AND at higher RPMS... the wires and plug all look good.. The truck is half warmed up doing this.. haven't waiting for it to get full hot, not sure when the TAD is supposed to activate ... guessing the actual air diverter is not functioning because of this???. I just ordered a NOS motorcraft air diverter off ebay , wont get it until the 12th... can't find an air bypass part at all.. can't find the TAD/TAB solenoids either anywhere.

is there an electrical test I can perform on the TAD solenoid to see if its getting a signal.

The TAB solenoid is pulling a nice vacuum for sure at the air bypass unit.

 

[DWilliamA]

EEC IV EGR solenoids will pass a little vacuum when closed, like maybe 2 inHg. The EGR valve itself is calibrated to not begin to open until it gets about 4 inHg applied.

If you are getting 2 inHg to the valve at idle, and it is hanging up open a little bit, then you've got a defective EGR valve.

On the other hand, if you are getting too much vacuum to the EGR valve at idle, you may be suffering from a plugged up orifice port or filter in the top of the EVR solenoid. The black plastic cap can be pride off with your fingers, and inside you'll find a foam filter and a vacuum port. That port will constantly be bleeding vacuum off, so if it gets plugged or if the filter is all mucked up, that will Force vacuum back out of the solenoid and over to the EGR valve.

I just checked it.. very little to none at idle... it increases as the RPM's go up..

 

[Motech]

running bad at idle afterwards too ....

Something occurred to me that I forgot before because it's been so long since I've encountered it...

Did you also mention when it's idling poorly, it smells like it's running pig rich?

Essentials are really sensitive to coolant level. The positioning of the engine coolant temp sensor is such that if the coolant level gets a little bit low, it develops an air pocket at the base of that sensor. When that happens, since the sensor measures fluid temperature but not air, it tells the computer that the engine is cold. Those old EEC IV brains could not Factor that it's been running long enough to be warmed up, and they would adjust for a cold running engine by enriching the fuel mix.

Long story short, check your coolant level.

Okay, I'm done now.

 

[Motech]

I just checked it.. very little to none at idle... it increases as the RPM's go up..

Okay, not done yet.

The vacuum level would be very slight, you probably would not feel it with your finger. You should feel it with your tongue though.

 

[Motech]

is there an electrical test I can perform on the TAD solenoid to see if its getting a signal.

There is, but there is no needed. The PCM tests that during KOEO srlf test and would throw a circuit code if there was an electrical issue.

 

[DWilliamA]

Okay, not done yet.

The vacuum level would be very slight, you probably would not feel it with your finger. You should feel it with your tongue though.

that is what I did... very little vacuum with tongue at idle... and it increases with RPM

 

[DWilliamA]

There is, but there is no needed. The PCM tests that during KOEO srlf test and would throw a circuit code if there was an electrical issue.

good to know

 

[DWilliamA]

Something occurred to me that I forgot before because it's been so long since I've encountered it...

Did you also mention when it's idling poorly, it smells like it's running pig rich?

Essentials are really sensitive to coolant level. The positioning of the engine coolant temp sensor is such that if the coolant level gets a little bit low, it develops an air pocket at the base of that sensor. When that happens, since the sensor measures fluid temperature but not air, it tells the computer that the engine is cold. Those old EEC IV brains could not Factor that it's been running long enough to be warmed up, and they would adjust for a cold running engine by enriching the fuel mix.

Long story short, check your coolant level.

Okay, I'm done now.

just looked coolant level is good .. how about the replacing the temp sender.. never replaced it before.. and my radiator is 2 years old hasn't had fix a leak crapped dumped in it or anything.

 

[DWilliamA]

good to know

Ya, chemical repairs are rarely effective.

I have restored air injection and EGR performance with the whackit technique many times to get those trucks through the smog test. (shhh...)

What if I pulled a robust vacuum on it .. from both ports back and forth action .. with a hand vacuum like for brake fluid changes... put some serious pressure on it.. wondering if its a fabric material inside that I could rip up though... so far banging on it didnt work. I took the actual tad solenoid out after knocking it out of its holder banging on it.. visibly looks ok

 

[DWilliamA]

replaced coolant temp sensor.. now it throws 21 every other time I test.. it threw the code once before I put the sensor in too... after I was banging on the TAD getting a vacuum the first time... all excited getting new codes... now it has thrown it after the new temp solenoid but not ever time.

I was able to get vacuum out of the TAD solenoid to the air diverter at idle... still throws 44... but ... I got vacuum 1 time.. then check it again and didn't .. then I hooked up a vacuum (brake line bleed vacuum tool) and pumped it up to 20 and it held with the solenoid in the closed position for what its worth ... and when I tapped on it.. each tap made it drop 3 or 4 points... very mechanical like step downs .. consistently 6 or 7 taps and it returned to 0 ... when doing this the tad solenoid out of the car. With the vacuum port plugged ... you can blow freely through the air diverter out line ... thinking this is ok because the valve/solenoid thing is in the closed position... meaning that when it opens it connects the vacuum in to the diverter line out so to speak... or should it be air tight at this point..??. if the solenoid leaks when open like it does when its closed it wouldn't pull a vacuum at the air diverter out line what I am thinking... and it does.. at least a couple times it has.

can't find any solenoids at local junk yards... a couple others to try further north. I don't know.. thinking the smog pump is out... or the bypass valve is stuck.. or the air diverter is stuck... something else.

Or so much carbon build up in the intake that even though the EGR is seemingly working properly.. the ports are plugged up maybe?

 

[DWilliamA]

I found a break in the thermactor pipe just behind the cat.

 

[DWilliamA]

jerry rigged fixed the thermactor pipe ... still get code 44

Now I am NOT getting vacuum out of the diverter in front of the TAD/TAB solenoids, nor the TAD or TAB solenoids either... i am getting vacuum to the diverter.

Not electrical expert... I put black and red volt meter test leads into the wire harness to the diverter .. like checking a battery.. and it reads 12v ..

What is the proper way to test the wiring harness to the diverter... ? nevermind.. no codes KOEO

 

[DWilliamA]

FIXED.... pretty sure.... It runs like a champ. but it still throws 44 KOER... memory code maybe? or will the computer eventually adapt to the current scenario and drop 44.. I only drove it for 15 minutes up some hills.... I could tell immediately upon starting the engine that it was running good.

So I ran some SeaFoam through the intake and it surprisingly made it run better, but not great, got to thinking, the symptoms all along have been identical to, certainly similar to the original symptom that started all this ... 2 really badly burnt spark plug wires... when I replaced the wires I also replaced the plugs too with NGK plugs. so for ***** and giggles I decided to pull plug #1 just to see... and sure enough it was bent over nearly touching the point. I checked the gap before going in and certainly didn't let a .10" gap get by .. s/b .44 per NGK... it was the seafoam that unfouled the plug which was getting worse and worse. I put in Autolites plugs this time.

at this point do I care about the code 44 thermactor system fault... ? I have a NOS motorcraft Thermactor Air Diverter (you know the "thing" back of the intake manifold) coming off EBAY... so that will get fixed regardless.

Is the Thermactor Air Bypass unit (you know the "thing" next to cylinder 4) worth trying to replace?

still not crazy about how the TAB/TAD solenoids seem to work now and then... not sure even when they are supposed to work.

thank you for the help so far ... further comments appreciated too
David.

 

[Tiha]

Glad you found it, that was quite the process and great effort.

Had similar problem with plugs. Friend of mine told me to try E3 plugs. Truck would not start below 30 degrees. Engine had 230k on it. Figured it was just wore out.

For some reason I swapped plugs back to cheap autolites and it was like a new truck again.