Code 34 & 44
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Code 34 & 44
Today I checked for codes and I got 34 O/C/R and 44 R. Only other codes are 67, 52 and 77 but I didn't floor the pedal or move the steering wheel nor did I depress the clutch. Both EVP and EGR were put in this year in January. I tested the EVP sensor according to this thread and it tested OK. The EGR holds vacuum and visually seems to be working fine. When I unplug the vacuum line from the EGR I have no change in idle but I think the idle should increase, shouldn't it? What else should I check?
Cargo Master
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From: Somewhere n North America
[QUOTE=minimalist;18731251] When I unplug the vacuum line from the EGR I have no change in idle but I think the idle should increase, shouldn't it? /QUOTE]
I don't believe the EGR operates at Idle, only @ cruising rpm.
I don't believe the EGR operates at Idle, only @ cruising rpm.
Cargo Master
Joined: Jun 2013
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From: Somewhere n North America
Have you checked the continuity/resistance of the EVP Sig wire to the ECA/computer connector?
Also, the SIG RTN/Ground wire ?
Cargo Master
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From: Somewhere n North America
Check the voltage at the TAD & TAB solenoid connectors.
Check the resistance of each vacuum solenoid, with the connector disconnected.
Check the vacuum hoses leading from the TAD & TAB vacuum solenoids to the Diverter & Bypass valves.
Check the resistance of each vacuum solenoid, with the connector disconnected.
Check the vacuum hoses leading from the TAD & TAB vacuum solenoids to the Diverter & Bypass valves.
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I checked the voltage last night at the TAD & TAB solenoids and I got 13.5v with the truck running. Also checked the signal voltage of the EVP again and this time I got .78v running and with KOEO. I also removed the EVP and checked the signal voltage and got .3v KOEO. Am I correct to assume that this points to an issue with the EGR valve?
Later this week I will check resistance, continuity, and vacuum. A few months back I did change all vacuum lines. High possibility that I messed that up.
In case it matters I should mention that I checked codes because I am trying to eliminate the last issues with idle surging. When I got the truck last November it was really bad but now it only surges when I start the truck after it warmed up or when I brake hard in particular when the AC is running. AC is dealer installed ( I think) and brake booster was replaced with a re-manufactured one also 2 month or so ago.
Later this week I will check resistance, continuity, and vacuum. A few months back I did change all vacuum lines. High possibility that I messed that up.
In case it matters I should mention that I checked codes because I am trying to eliminate the last issues with idle surging. When I got the truck last November it was really bad but now it only surges when I start the truck after it warmed up or when I brake hard in particular when the AC is running. AC is dealer installed ( I think) and brake booster was replaced with a re-manufactured one also 2 month or so ago.
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And thank you for taking the time and helping me.
Fleet Owner
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No, the EGR valve preloads the EVP sensor when installed on top of the EGR valve. Perfectly normal for the output to drop a few hundred mV when removed. Many of the aftermarket EVP sensors have a shaft that is too long. If you are certain the EGR valve is fully closed then shave off a bit of the shaft until the closed value output is within range.
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Cargo Master
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From: Somewhere n North America
TAD & TAB 50-100 ohms.
EGR 65-110 ohms.
EGR 65-110 ohms.
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Cargo Master
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From: Somewhere n North America
I tested the EVP sensor according to this thread and it tested OK.
Check this one; Fuel Injection Technical Library » EGR Valve Position sensor (EVP)
You can also shim the EVP up by adding another washer or some spacer material under the screws temporarily until the voltage is in the closed range to see how much you need to shave off the shaft as Randy indicated.
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Found some time yesterday and did test resistance of the TAD, TAB and EGR/EVR. All tested fine. Over the long weekend I will triple check the vacuum lines.
To test if the EGR valve was seated correctly I did a smoke test and if it wouldn't be seated correctly I would see smoke, wouldn't ?
To test if the EGR valve was seated correctly I did a smoke test and if it wouldn't be seated correctly I would see smoke, wouldn't ?
Fleet Owner
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From: Kentucky
That will usually verify if the valve is seated or not.Based on your results and troubleshooting it is probably okay.
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Code 34 is gone after I shaved the shaft of the EVP. Still working on code 44.
I have been driving the truck a bit more over the last days to figure out a pattern when the idle surges. There are basically 3 things that trigger it:
1) Warm start. Typically the engines idles about 4 times before it settles into a stable idle around 750 RMP. This is worse when the AC is turned on. With AC the engine typically stalls right away.
2) Truck is running and warmed up and I turn on the AC. Again about 4 or so surges before it settles to a steady idle.
3) Slowing down. I have the habit of pressing the clutch pedal and putting the truck into neutral when approach a stop or a turn. The truck apparently doesn't like it and starts surging and occasionally stalls. In particular when the AC is running. If I just slow down and put the truck into neutral or change gears very late, looks like there is no issue.
Since it is worse with AC I'm going to get the AC checked but I don't think the AC causes the surging but rather amplifies the issue. The only common factor I see so far is engine temperature so I'm going to check the ECT as well. Anything else?
I have been driving the truck a bit more over the last days to figure out a pattern when the idle surges. There are basically 3 things that trigger it:
1) Warm start. Typically the engines idles about 4 times before it settles into a stable idle around 750 RMP. This is worse when the AC is turned on. With AC the engine typically stalls right away.
2) Truck is running and warmed up and I turn on the AC. Again about 4 or so surges before it settles to a steady idle.
3) Slowing down. I have the habit of pressing the clutch pedal and putting the truck into neutral when approach a stop or a turn. The truck apparently doesn't like it and starts surging and occasionally stalls. In particular when the AC is running. If I just slow down and put the truck into neutral or change gears very late, looks like there is no issue.
Since it is worse with AC I'm going to get the AC checked but I don't think the AC causes the surging but rather amplifies the issue. The only common factor I see so far is engine temperature so I'm going to check the ECT as well. Anything else?
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I have a feeling I am missing or overlooking something. The only time the idle surges is when the engine is warm and I either start the engine, turn on the AC when idling or when I slow down with clutch depressed. Most of the time the surging is not too bad but occasionally it stalls. Any pointers are more than welcome.