I found my 1989 F350 351w truck was throwing a code 33 which means my EGR isnt opening fully. So, I want to try and fix what I have before dumping money unnecessarily. I know very little about how these ears EGR functions, so please pardon my stupid questions.
1. Where is the EGR located on this engine? I know my 84 has it under the carb but since its obvciously efi, is it that thing that sits above the alternator?
2. I also heard that it could be my EVR. How can I test it with a multimeter to check its function?
3. Is there a way to check if my egr is clogged but manually applying vacuum to it?
4. If its clogged, how does one remove and clean it?

Thank you very much.

 

I have and 1988 F250 351. My EGR (code 33) acted up a few years ago. I can't remember exactly how I fixed it but here's a few ideas.

On my truck the EGR is on the left front (facinging the engine). There is a tube coming up from the left side exhaust manifold next to the #1 cylinder exhaust port. The EGR is about the size of your fist and is on top of the tube. It has a vacuum hose and and two electrical leads coming off the side and top respectively.

The problem can be the EGR, the electrical actuator (EVP) on the top of the EGR, the vacuum hose or the vacuum regulator which is on the driver's side to the left of the brake booster.

I would first try to make the EGR operate manually by applying vacuum from another source. Remove the vacuum line from the EGR, attach another hose and use a hand vacuum pump or a spare vacuum port on the manifold. Have the truck idling normally and apply the vacuum. A noticeable roughness should develop as exhaust is let into the intake. If it does the EGR is probable ok.

Then I'd look at the vacuum line for cracks (if it's still the plastic kind they are known for problems). The EVP should show a certain voltage between the two wires (backprobed) with the key on. I think it was .6v (I'm not sure). When the computer tells it to open the EGR is getting about 5v. A digital mutimeter is what I used - it needs to be accurate.

I had the vacuum regulator go on my truck. Even though the EGR would work when I manually applied vacuum, normal engine vacuum would never get to the EGR through the vacuum regulator.

Post back.

 

I take it that it will not pass inspection with the code or you would not be worried about a 33.
The EGR only opens with a warm engine at high way speed at mid throttle the same as the purge solenoid.

jemini describe it very well but here is a photo of the EGR valve, EVP and the EVR.





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Not exactly. Im trying to figure out why if I drive at part throttle it runs great, but if you floor it, it falls flat on its face and barely accelerates. Since the GR was the only code I got, I assumed that was the culprit

 

A 33 says that the valve did not open and if the valve did not open it should run better.
Unless of course you have a vacuum leak causing the 33 then it may not run as well.

Continuous Memory Code 33 indicates that the EGR valve did not open with the engine stabilized and with EVR solenoid duty cycle present sometime during vehicle operation.

Possible cause:
-- Obstructed or cracked hose to EGR valve.
-- Damaged EGR valve.
-- Damaged EVR solenoid harness.

 

Check for slop in your timing chain, should not be more than about 4-5 degrees.
If OK check your Ignition Timing with the SPOUT out, it should be at 10 degrees BTDC.

 

I've got an Innova 3145 OBD I code reader and I'm getting a Code 33 in continuous memory (CM) and during the engine running test. Vehicle is a 1988 Ford F-350 with 351W. My engine tends to stall when I stop and the engine is at an idle. The instruction book that came with the Innova states for Code 33:

(Cars ONLY): EGR valve not opening properly.
(Trucks ONLY): EGR valve fault / not closing properly

So is the Code 33 on my Truck meaning the EGR isn't closing, and that could explain the stalls when I come up to the stop lights?

 

The manual that came with the Innova 3145 has a lot of errors in it.
The manual is good for setting up and running the tests but do not go by what the codes say in it.

The 33 code for a 5.8L engine in a 1988 Light Truck from the Ford Factory Shop Manual from Ford (Engine/Emissions-Diagnosis Shop Manual) means the EGR valve is not opening.
They made it and they should know.

Code #34 means it did not close.

 

OK. Thanks for the follow-up. I'll read some more here on Code 33 troubleshooting and see if I can't figure out the source. Doesn't sound like this Code should cause the stalling I'm experiencing anyhow.

 

In my limited experience, the pintle that moves the valve in the egr can get sticky, it did in my truck. I sprayed a little bit of lubricant on it and then moved the valve up and down a few times with a screwdriver to lube it up. Egr issue disappeared. Worth a try, free and easy.