94 B4000 Code 33 help

[Steve777]

Well after years of flawless running, my 1994 B4000 finally is having a problem. The engine light came on a couple of days ago, no symptoms and it was gone the next time I started the truck. Then today the engine light came on after starting and stayed on. Tried turning the engine off and restarting it, but even though it would crank it would not fire at all. Let it sit about 30 mins, and then it was back to how it was before, would start and run but the engine light came and stayed on shortly after starting.

I let the engine warm up and then pulled the codes by sorting the test plug. Only one code, a 33. Which seems to be EGR related. I have done some searching here, and it seems that it may be vacuum hose leak related, or the solenoid related or perhaps the EGR valve is stuck. Since I have not had to dig into any problems with this truck yet, I am not sure where all these parts are, or which ones are the most likely culprits. So I thought I would ask here for advise. Where's the "low hanging fruit" here, what should I check first? Anyone willing to chime in.

 

[RonD]

Very odd code for 1994, should be 3 digit codes in 1993/4 computers

Can you retest for the code, it should flash the CEL with any set codes with key on and Jumper wire in place
So count the flashes, should be in groups of 3 then longer pause, then repeats, there are no "0's"

And a 1994 4.0l shouldn't even have an EGR Valve unless it was originally sold in California, just FYI

You can get a length of vacuum hose and attach one end to the EGR Valve
Start engine, cold or warm doesn't matter
Suck on the end of the hose, EGR Valve should open and cause engine to stumble, stop sucking
Idle should return to normal
Do it again, and again
If idle always returns to normal then EGR Valve is OK and not sticking open

The trucks EGR vacuum hose should never have vacuum present when engine is cold or when idling, put you finger on the end to test for vacuum at idle, if it has vacuum then EGR solenoid is stuck OPEN and it is opening the EGR Valve

 

[Steve777]

Opps, title had a typo (corrected now), it is an '94, and confirmed that both on the registration and the owners manual.

Not sure what to say on 2 vs 3 digit codes. I certainly could have pulled them wrong, I was just following the instructions I found online. I warmed the car up. Shorted the two pins on the "electrical test" connectors together. Started the car. Saw the three flashes (which is supposed to mean a v6 engine which is what is there). Waited for the single flash. Turned the steering right then left then floored the accelerator. Waited, then there was a series of 3 flashes, a pause, and then 3 flashes, a longer pause, then a repeat of the two series of three flashes. I repeated this twice with the same results. If this isn't the right procedure let me know. It is possible that this was originally a CA car, no clue on the previous owners or history before the guy who sold it to me.

I was thinking that it might be a sticky ERG valve, in that might explain the non-starting. Thanks for the info, I will check the codes again, but expect it will be the same. Also will locate the ERG valve and do your vacuum test, that would be good to confirm or eliminate as a cause. And double check the vac hoses going to it.

Just out of curiosity, if this was a Calif car originally, would they have kept the computer that generated the 2 digit codes? or should it have gone to the 3 digit ones? (just trying to see if maybe this has an older engine/computer transplanted into it).

 

[RonD]

You were running a diagnostic test

Just jumper for self test and turn on the key, don't start the engine
And watch the CEL

Google: How To Run A Self-Check On Fords 1987-1995
Watch the 3min video


Look on rear edge of drivers door for the BUILD info, take a picture of it
Read here: https://www.therangerstation.com/Magazine/Summer2009/federal_sticker.shtml

Federal emissions or Calif emissions will be on that label

 

[Steve777]

Thanks RonD.

I checked the door sticker; built 8/1994 and meet all Federal emissions. So would seem to not be a CA truck.

I also looked on the engine, and it sure looks like there is an EGR valve. On driver's side of the intake manifold, a vacuum actuated (eg diaphragm) valve, opens into the intake, input from the exhaust manifold down below. There is a control solenoid right next to it which appears to regulate the vacuum. No obvious holes/tears in the vac lines at the valve end.

Will try your suggestion on the EGR test later today to see if it might be sticking open. And will also run a self test then too. (need to run out for a while now).

 

[RonD]

Its a 1995 model with build date of 8/94, so very odd to have OBD1 in the first place

And yes all 1995 4.0l will have EGR valve and a Cam sensor

Ford's cut off dates are June for model years, 7/1994 to 6/1995 are 1995 model year
7/1993 to 6/1994 would be 1994 model year

1994 was the first year Ford was building the B-series for Mazda so that may be different
But any 4.0l installed after 6/1994 would have the EGR Valve per 1995 model year specs, Ranger or Mazda

 

[Steve777]

Finally had a chance to run the self test. Found it really hard to count flashes, so did it a few times, and I think this is right.

Initially got two 1-1-1 codes. From what I could find this was a pass, no errors. Seems right in that now the check engine light does not come on when running anymore. Not sure what changed but it did.

Then there seems to be a pause and then some other codes come out, which I presume are the old stored codes. a 157 (mass air flow), 215 (coil #1), and maybe a 214 (cam position sensor, it was hard to count and the 214 and 215 may be just one code with me missing a flash).

So I am a bit puzzled as to why the check engine light problem just went away on its own, but not complaining. What I'd like to do is clear these old codes so that I can see what new/current problems there are from now on. Have not seen anything in the vids that give a way to do that. Anyone know if it is possible without one of the reader thingies?

 

[RonD]

Yes, 1 1 1 means no current issues/codes
Yes, those were old codes

With self-test jumper in place and after the codes have flashed, leave the key on and pull out the jumper, that will clear the codes, then turn key off

OR

Disconnect one battery cable for 5 minutes or so then reconnect it