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semcha · 06-08-2018, 06:11 AM

I can't tell if my reply got lost in all the images.

The full series on the reader was 334, 10, 334, 1, 111, 111.

Sean

ransil · 06-08-2018, 06:16 AM

Another guess is the electrolytic capacitors in the computer, they go bad after time.

subford · 06-08-2018, 06:58 AM

Quote:

Originally Posted by semcha

I can't tell if my reply got lost in all the images.

The full series on the reader was 334, 10, 334, 1, 111, 111.

Sean

There should not have been a 10 between the two 334.

It would have been:
334, 334, 1, 111, 111
OR
334, 334, 10, 111,111

/

semcha · 06-08-2018, 10:08 AM

I ran it again because I figured I must be remembering wrong. I got 334, 334, 10, 111,111 on the key on/engine off check.

Sean

subford · 06-08-2018, 10:30 AM

DTC 334 in Key On Engine Off (KOEO) or Engine Running (KOER) Self-Test indicates the EGR valve and/or EGR Valve Position (EVP) sensor may not be fully seated in the closed position. The EVP sensor voltage is greater than the closed limit voltage of 0.67 volt. Because of the preload on the installed EVP sensor, it is difficult to determine whether the EGR valve is seated or the EVP sensor is in contact with the EGR valve stem.

Possible causes:
-- Poor continuity in EVP sensor harness.
-- Non-seated EGR valve.
-- Damaged EGR valve.
-- Damaged EVP sensor.
-- Damaged EVR solenoid.
-- Damaged Powertrain Control Module (PCM).

Disconnect vacuum hose from EGR valve and plug hose.
Rerun KOEO and KOER Self-Test.
Is DTC 334 present?

If the EGR valve is not closing you will get less power and it may not idle or very bad idle.
I blocked mine off with a coin in the EGR tube. The other end of the was broke off anyway. Just plugged the hole in the headers that I put on the RV.

THenne1713 · 06-08-2018, 11:18 PM

an OBD-II reader can be had for $20 (Amazon) or Autozone & others w/ read codes for FREE. LIMP mode, according to my Ford OM Book reading, is engine overheat temperature initiated, converts to using 5-cylinders as air compressors for cooling to get you off the interstate onto the roadside or exit... not meant for driving 20-miles... just for EMERGENCY LANE/ EXIT, THEN shut down/ investigate and allow to COOL.

chboone · 06-09-2018, 12:09 AM

Quote:

Originally Posted by THenne1713

an OBD-II reader can be had for $20 (Amazon) or Autozone & others w/ read codes for FREE. LIMP mode, according to my Ford OM Book reading, is engine overheat temperature initiated, converts to using 5-cylinders as air compressors for cooling to get you off the interstate onto the roadside or exit... not meant for driving 20-miles... just for EMERGENCY LANE/ EXIT, THEN shut down/ investigate and allow to COOL.

OP's unit is a 94 is OBD I, does not have an OBD II port.

ransil · 06-09-2018, 05:56 AM

EGR might be throwing a code but I doubt it is causing the issue, if stuck open the motor would not start or idle really bad.
To test the EGR put vacuum pump on the EGR valve port, start engine at idle open the EGR valve with the vacuum pump, engine should stall or run really bad.

semcha · 06-09-2018, 02:09 PM

Tried plugging the hose. Ran the Key On Engine Off, still got the 334.

I ran the Engine On too. I got the 334 too. I also got a 116.

Sean

subford · 06-09-2018, 02:42 PM

Then:
Key off.
Disconnect EVP sensor.
Inspect the connectors on harness and sensor for damaged pins, corrosion, loose wires, etc. Service as necessary.

Remove vacuum line from EGR valve.
Exercise EGR valve by applying and releasing vacuum with a vacuum pump.

Reconnect vacuum line to EGR valve and electrical connector to EVP sensor.
Rerun KOEO and KOER Self-Tests.
Is DTC 334 still present?

116 just means you had a cold engine.

ransil · 06-09-2018, 02:48 PM

Quote:

Originally Posted by semcha

Tried plugging the hose. Ran the Key On Engine Off, still got the 334.

I ran the Engine On too. I got the 334 too. I also got a 116.

Sean

At idle there should not be any vacuum on the EGR port, EGR strategy is engine at operating temperature and some RPM above idle.

semcha · 06-29-2018, 02:49 PM

Sorry for the delay. I had to get a vacuum pump. I am not seeing anything wrong with the harness, but it does have some kind of lubricant in one of the connectors. Do I need lubricant in the others? I'm still getting the 334 error.
Does this mean I need to replace the harness? I found this one: https://www.oreillyauto.com/detail/b...ford/f53?pos=0, but it has 4 terminals instead of 3. Mine looks like this one: https://www.partsgeek.com/gbproducts...2#immersedview.

subford · 06-29-2018, 07:20 PM

Quote:

Originally Posted by semcha

I am not seeing anything wrong with the harness, but it does have some kind of lubricant in one of the connectors. Do I need lubricant in the others?

The stuff in the connectors is dielectric grease to prevent corrosion.

Quote:

Originally Posted by semcha

I'm still getting the 334 error.
Does this mean I need to replace the harness?

I would not think so.

You might want to look at this link:
Fuel Injection Technical Library Â» EGR Valve Position sensor (EVP)

/

semcha · 06-30-2018, 10:56 PM

Quote:

Originally Posted by subford

The stuff in the connectors is dielectric grease to prevent corrosion.

I would not think so.

You might want to look at this link:
Fuel Injection Technical Library Â» EGR Valve Position sensor (EVP)

/

Well, in a strange turn of events, I was reading up on the EVP and ran across a post on another forum from 2012 by you that mentioned looking at the ground wire from the battery. When I crawled under the rig to trace the wire, I saw that my transmission fluid pan gasket was leaking. Fluid was sprayed around the gasket at multiple points and a little fluid was dripping off the bottom of the pan. So clearly, I need to fix that. I also recall reading on a few sites that transmission issues will definitely throw the engine into LHM. I assuming loss of pressure and overheating. That is now top of my list to fix, but I think that might be the winner. Why wouldn't that issue throw a code?

Sean