code 33: advised action?

[BerniniCaCO3]

Had my battery disconnected 2 weeks ago (erases obd1 codes, right, so this isn't detritus from last year?)

Decided to read codes: believe it or not, i've never read obd1 codes before, so I'm not sure whether I did it right.
I heard all the relays test, then the little tester (yeah, I know a $2 test light would also have worked) blinked once, pause, once pause once, pause, once pause once, pause, three rapid flashes pause three rapid flashes, pause, three rapid flashes pause three rapid flashes.

I read actron's booklet, and I believe the first 5 blinks were basically irrelevant, and, that it showed I have code 33 twice? It repeats the codes you have, twice?

I also read a friend's 1989 bronco tonight for kicks, and it acted almost the same way, and seemed to read 41, 33, 41, 33; so it repeated, also. Guess just to make sure you didn't miss 'em.



Establishing that I read my morse code correctly,
33 is probably "ALL - EGR did not open/ respond during test or if memory code, did not open intermittently - EVP EVR PFE"
although once source also claims "throttle positioner sensor noisy/harsh on line"

Which is it?

If it's the EGR, what should I do about it?
What fixed yours?
Especially since me and Jake both have the same code, 33, on our fords, so we can both use your advice.
Did you clean the egr solenoid?
Did you replace the solenoid?
Did you replace the egr position sensor?
Did you replace both the position sensor and the solenoid?
Or was it neither, and a wiring concern instead?


By the way, what would the performance symptoms of this be? Poor wot performance and poor fuel economy explained, perhaps?

[BerniniCaCO3]

For a bit more background, the engine was rebuilt less than a year ago: the egr passages will not be clogged with soot. I did make an effort to clean the solenoid itself, but not a sincere one, not really knowing how to get inside of it... may have just sprayed it with throttle body cleaner and called it good.

Question: if you DO recommend replacing the solenoid or the position sensor or both, is this one of those things where motorcraft can really matter? Or are bwd, airtex wells, and other known brands generally quite good?

[mercurygm88]

I had a code 33 on my 88 and it was the solenoid. I bought the bwd from oreillys back in october 2011 and its still working.

[BerniniCaCO3]

OK, just went to rockauto.

There's the valve itself:

http://www.rockauto.com/catalog/moreinfo.php?pk=935446

The pressure feedback sensor:

http://www.rockauto.com/catalog/moreinfo.php?pk=929780

And then the "solenoid":

http://www.rockauto.com/catalog/moreinfo.php?pk=945010

The solenoid looks like those two things I've got dangling across the upper intake plenum on the backside, bolted on by the plenum cover.
I thought both went with the airpump system? Perhaps that's still true, and rockauto simply has it mislabeled "egr vacuum solenoid." If one of them does affect the egr though, which one is it?
Or maybe there's a third one hanging on the front side of the intake plenum opposite the airpump ones... I should pop the hood and take another look.
I've got the airpump system removed, and its vacuum lines capped off, but the solenoids are still plugged in.

[86VickyLX]

Fix the stupid most likely broken green plastic vacuum line.
If you still have that code. Your EVP sensor is wrong.

[gadget73]

yup, check for vacuum line problems first. Also I would use a vacuum pump to apply vacuum to the valve to make sure it opens and holds. A ruptured diaphragm will also cause this code.

41 means its running lean on the right side. 89 Bronco should only have one sensor, so I guess it only gives one lean code. Check for vacuum leaks. Contrary as it sounds, O2 sensor related codes are usually not the O2 sensor at fault.

[86VickyLX]

contrary as it sounds, o2 sensor related codes are usually not the o2 sensor at fault.

x1000!

[BerniniCaCO3]

"41 means its running lean on the right side" ah, OK
No, I know that O2 code does not = O2, but my little actron booklet worded it as "O2 not switching."
If an O2 sensor is stuck at one voltage level, then it probably IS the O2 sensor, and the way the book worded the code description made it seem that way.

If that's not what it means --it just means running lean-- then I have to agree.
And I know for a fact that the bronco has at least one 1/8" vacuum leak that I know of.

[BerniniCaCO3]

and yeah, just one O2, for the entire car [for the bronco]. I was surprised. It's positioned in the H of the h pipe junction.

Apply vacuum to the egr valve, and I should see it suck in?

I'll make sure that vacuum is making it to the solenoid, too. That makes sense now (how it works). The green line is definitely ok, but there's a red line too that goes to the solenoid in the first place (and the green line goes from the solenoid to teh egr valve), and i haven't traced its whole length. If vacuum is lost in the red line, then it would have the same effect.

[gadget73]

it should be visible if you look closely but more importantly you want to make sure the vacuum level holds and doesn't just drop off.


depending on the specific test, code 41 means either of these, which are pretty much the same thing.

HEGO sensor circuit indicates system lean (right side).
No HEGO switching detected always lean (right side).

I don't know the batch fire system terribly well but I know it only has one sensor, so I'm assuming that it can only possibly give one code. It only needs one oxy sensor because its incapable of adjusting fuel bank to bank. With the sequential system the cars have, there are 8 injector drivers and the ECM can in theory adjust the pulse width to any of those 8. In reality it adjusts 1-4 as a set, and 5-8 as a set. With batch fire, there are 2 injector drivers, usually one feeds 1, 4, 6, 7 and the other runs 2,3,5,8 or something like that. It can't adjust things left to right since each injector driver will run a pair of injectors in each bank. Why they do this instead of 1-4 and 5-8 is not something I know.