OK, so I finally got around to pulling the codes on my truck.

FWIW: 92 F150 2WD 5.0L E4OD w/ just under 113K miles.

Did a "tune up" last week, but did not run or drive it until today.

("Tune up" was new Autolite Copper Core plugs, Summit 8mm wires, Motorcraft cap & rotor, oil & filter and air filter change.)

From the "1992" printed in the Motorcraft wires, it is possible that this was the truck's FIRST "tune up".

Meant to pick up a PCV valve when I was at Advance today but forgot... but it looks like I will be back there tomorrow...

Pulling and cleaning the TB and IAC are still on the "to do" list and should be done tomorrow AM.

ANYWAY... here is what I got:

KOEO

11

11

1 - Seperator Pulse

CM

41

33

41

33

According to FFI they translate to:

41 HEGO System Circuit inticates system lean (right side)

33 EGR valve opening not detected


Sooo... what do you guys think?

Am I looking at replacing an EGR valve and an O2 sensor?

Thoughts and help are GREATLY appreciated... I am still learning the ways of the Blue Oval.

Thanks.

-cmc-

 

Vac leak could cause both codes, how does it idle kinda high?

leaking vacuum causing lean condition, same vac leak reducing overall engine vac so egr valve doesn't open.

Keep in mind "Right side" is meaningless on most these trucks, only has the one O2 sensor.

You may need a new O2 sensor but first make sure you have no vacuum leaks. If the O2 sensor is original to the truck, like it sounds like the wires where, it would be best if you replaced it. Replaced for best performance/economy, not necessarily as a repair for the lean condition. As you probably know O2 sensors do not last the life of the vehicle!

 

Idle... actually seems to idle low to me. But that could just be because it is so darn quiet at idle. (Compared to the Header'ed and Flowmaster'ed 4.0L in my GC).

Does the "hunt-and-lope" when first started, but I attribute that to the IAC needing to be cleaned.

No obvious vacuum leaks. But I'll check in the AM... warm it up and stick the vac gauge on one of the lines coming off the intake.

I think almost everything on this truck is original... so an O2 sensor might be in my future. Easy enough, and cheap enough. Was just hoping I could put it off until I did some exhaust mods...

Thanks.

-cmc-

 

Did you check the timing with a light?

The low idle could be because of the base timing is off, masking an otherwise high idle caused by a vac leak.

A vacuum gauge is one of the better ways to set the timing on a higher mileage motor, timing light doesn't make up for worn parts. At the same time still using a light to get an idea where its at.

With these motors its very important there is no vacuum leak, even a small one will cause problems. Problems a carbed motor wouldn't have the slightest issue with. Small vac leaks can be very hard to find so take your time and look/listen very close. If in doubt I use water from a garden hose to check for them, if nothing else sometimes just to prove there is not one. I don't own a smoke machine.

 

It's very possible that you've got cracked lines if the truck hasn't been touched in so many years. The coffee can vacuum canister might also be rusted out on the end or bottom, which is pretty common. Using your gauge is a good way to get an idea of what's up. I went far enough to install a permanent one in the dash.

If you replace the o2 sensor, Bosch is the OEM brand, so pay for another one and don't go for the store-brand crap. I learned that on my 90.

 

I have not checked the timing at all. Though I have seen a lot of references here to base timing being 10* BTDC and advancing it to 4* BTDC making performance and power gains.

I have never timed an engine using a vac gauge, only used a light... any tips?

Also, using water to look for a vac leak... same concept as looking for an air leak using water with a coupla drops of dish soap in it?

The truck actually runs smooth and feels strong.

Tune up made a big difference... one that I could actually FEEL.

The truck is actually in very good condition. Just some neglected PM. I'll give the coffee can a good checking tomorrow as well.

O2 sensor is worth the $... and RockAuto has the OE Bosch for +/-$30. I'll be ordering one this week.

So, you guys think the 33 / EGR code is really a vac issue?

Thanks.

-cmc-

 

I would clear the codes and see what pops back up. Remove the jumper while the codes are flashing clears them iirc.

 

I have not checked the timing at all. Though I have seen a lot of references here to base timing being 10* BTDC and advancing it to 4* BTDC making performance and power gains.

Yes you can bump the timing up to 12, 13 even 14 deg BTDC but be aware of spark knock. Myself I tried it and found I lost to much at the bottom end, pulling a trailer all the time that is where I need/use the power more so I dropped back down to 10deg BTDC. Experiment with it a little and find the sweet spot for your motor and driving habits/needs.

I have never timed an engine using a vac gauge, only used a light... any tips?

If you buy the right gauge its laid right out on the dial face for ya, help flatten out that "learning curve" for a guy that never used one before. Vac gauge can and will tell ya a lot about a motors setup and condition.

Also, using water to look for a vac leak... same concept as looking for an air leak using water with a coupla drops of dish soap in it?

Nope, no soap involved. I turn the water on so its a solid stream, medium flow, not flying right out the hose, need volume not pressure. With the motor running start low directing the water flooding the seams where the matting surfaces are bolted together IE; Lower intake to cylinder head. If its sucking air at any point it will suck in the water there to. If it sucks in water it will blow steam out the tail pipe. Work your way back to front, low to high IE; lower intake then upper intake matting surfaces, one side then the other contentiously watching for steam, if you have a leak and hit it with the water steam will immediately pour from the tail pipe. Have someone watch the pipe as you work the hose. See steam back off let it clear then hit the area again until you narrow down exactly where its sucking air at. While I try not to flood the water to high I have had the injectors completely under water without any adverse effects, rare though.

The water will not harm the motor by sucking it in, in fact it works great for cleaning away any carbon deposits. Just be sure and let the motor run for several minutes when your done to allow the water to be passed, fully flushed away internally.

The vac lines I test with a hand vac, however I have used the hose method on them too though!

So, you guys think the 33 / EGR code is really a vac issue?

The code you get leads one in that direction yea. A failed O2 sensor should or would throw a code "HEGO switching not detected" (Words to that effect). You get "system lean" like the sensor works, leads one to think the system is lean then, IE a vac leak or a fuel delivery problem. Vac leak on these trucks is probably most common because of the plastic lines. Having said that, yea it could be just a bad sensor. LOL!

 

Cool. I'll get to that later once I finish catching up on the PM and it's other little problems.



I'll look at my gauges in the morning. I have two different ones out in the garage.

Was planning on checking it. I have always heard that 20-22mmHg indicates a pretty strong/tight motor. Will be interesting to see what I get.

.

Makes sense. Another thing on the "to do" list for tomorrow was hose out the engine compartment/motor.


I have a new fuel filter that needs to be put in too, so mebbe I'll take care of that first since the "lean" condition could be a fuel delivery issue.
Prolly still go ahead and replace the O2 sensor. $30 ain't much; and the one in there IS 17 years old...

Thanks guys.

Gotta take the boy to day care in the AM, hit the gym, then in the garage by lunchtime tomorrow... so more tomorrow afternoon.

-cmc-

 

check the vac resevior when your doing your vac check... found mine to be completely rusted out on the bottom and fashioned a new one out of a piece of pipe and some muffler cement and its all good now... good luck to you