Good morning all,
Due to a slight oil leak I replaced the three vacuum pump seals on Tuesday, on Wednesday I get an EML and a 4501 code, MAF values at idle up at 64 kg/h when it's usually around 30-35. Thinking I've somehow destroyed the vacuum pump I popped the vaccum hose to the brake servo off and I have vacuum, albeit by feel. Popped the hose to the egr valve and no vacuum. A quick bit of research and in the absence of a vac. tester I decided to go ahead and replace the egr pressure converter as a lot of similar issues report this to be the source.
Intake manifold off, new Pierburg PC installed with 4mm ID silicone vac. hoses installed from the 4 way feed to PC and PC to EGR valve and inspected the remaining hoses and all appear to be in good order. Fire her up, clear codes, MAF values down to 30-35 kg/h, popped EGR vac. hose and I have vacuum albeit by feel, job done...or so I thought.
Took it for a drive last night and the idle felt off, smooth and around the normal RPM but it felt fast somehow. Checked the live values and the MAF readings are back at 64kg/h and the 4501 code is back, no EML yet though.
My next steps.
Am I barking up the right tree, any additional advice or feedback is much appreciated.
Due to a slight oil leak I replaced the three vacuum pump seals on Tuesday, on Wednesday I get an EML and a 4501 code, MAF values at idle up at 64 kg/h when it's usually around 30-35. Thinking I've somehow destroyed the vacuum pump I popped the vaccum hose to the brake servo off and I have vacuum, albeit by feel. Popped the hose to the egr valve and no vacuum. A quick bit of research and in the absence of a vac. tester I decided to go ahead and replace the egr pressure converter as a lot of similar issues report this to be the source.
Intake manifold off, new Pierburg PC installed with 4mm ID silicone vac. hoses installed from the 4 way feed to PC and PC to EGR valve and inspected the remaining hoses and all appear to be in good order. Fire her up, clear codes, MAF values down to 30-35 kg/h, popped EGR vac. hose and I have vacuum albeit by feel, job done...or so I thought.
Took it for a drive last night and the idle felt off, smooth and around the normal RPM but it felt fast somehow. Checked the live values and the MAF readings are back at 64kg/h and the 4501 code is back, no EML yet though.
My next steps.
- Vacuum test the EGR valve engine off.
- Apply vacuum on/off while the engine is running monitoring MAF readings.
- Vacuum test the feed to the EGR valve.
- Vacuum test the EGR feed while blocking the vacuum feed to the brake servo.
Am I barking up the right tree, any additional advice or feedback is much appreciated.
