Monday, 15 June 2015

Issues, Emissions & MOT Failure

6/3/15 - Fail on MOT Emissions

Had yearly MOT today. FAILED! A few simple points like rear fog lights. On major failure was the emissions. CO % Fail and Lambda Fail. CO was 0.435% Lambda was 1.807 at Fast 2500-3000rpm

Initial thoughts where the Lambda sensor. Replaced Lambda sensor. Found the old one was very black with soot. Indicates Running Rich (as does the CO readings being well out) The problem is that the Lambda is showing it really lean.

Retested and still the same High CO and High Lambda. How can I have an engine which is Rich & Lean. Too much Fuel & Too much air!

8/3/15 - Retest

Anyway manged to get it through MOT after a long warm up and pressing the emissions test at the right place so I have a years ticket but still have issues. 

Still CO & Lambda where way over but  having a Fast at 4250-4850 rpm bought the levels down if we pressed the test button at the right time.

I have also noticed that the fuel consumption is higher & exhaust (lambda sensor & tail pipe have black soot)

Investigations / Cause:

OK so I have a number of things which can cause High CO and High Lambda:

Found this table:


(Legend: L = Low, H = High , M = Moderate)
COCO2HCO2Possible Problems

H

L

H

H
Rich mixture with ignition misfire

H

L

H

L
Faulty thermostat or coolant sensor

L

L

L

H
Exhaust leak after the converter

L

H

L

H
Injector misfire, catalytic converter operating

H

L

ML

H
Rich mixture

H

H

H

H
Injector misfire, catalytic converter not working; combination of rich mixture and vacuum leak

L

L

H

H
Ignition misfire; lean condition; vacuum or air leak between air flow sensor and throttle body (false air)

L
H
L

L
Good combustion efficiency and catalytic converter action

L

L

L
All systems operating within tolerance; normal reading


The following table lists some of the results possible when the AFR (air-fuel ratio) is sustained at conditions ranging from too lean to too rich.
ConditionsResults
Too LeanPoor engine power
Misfiring at cruise speeds
Burned valves
Burned pistons
Scored cylinders
Spark knock or ping
Slightly LeanHigh gas mileage
Low exhaust emissions
Reduced engine power
Slight tendency to knock or ping
StoichiometricBest all-around performance
Slightly RichMaximum engine power
Higher emissions
Higher fuel consumption
Lower tendency to knock or ping
Too RichPoor fuel mileage
Misfiring
Increased air pollution
Oil contamination
Black exhaust

So from this information I think it could be the following:


  1. Fault Code on ECU
  2. CAT Not working 
  3. Exhaust Blockage / Restricted / Leaking 
  4. MAP Sensor
  5. Coolant Sensor (Oil Temperature)
  6. Dirty Injectors / Stuck Fuel Injector
  7. Fuel Pressure Regulator / Too High Fuel Pressure
  8. Blocked Air filter
  9. Faulty Lambda Sensor
  10. Faulty PCV Breather
  11. Tappet Adjustment
  12. Faulty Charcoal Valve
So in order to diagnose I thought I would take my time and not rush out and buy expensive parts. I have done the following investigations.

1. Fault Code on ECU - Check ECU and only one fault code which my van has had ever since I purchased it - Throttle Valve position - I think this is just the Zero setting for throttle body when installed. I ran VCDS and logged the data and compared it with a log I ran a year before. Could not see any differences.

Still to test - 
Find out how to reset throttle position to clear fault code for ever. Need to get the correct process in VCDS and try setting.

2. CAT Not working
Could be a blocked or non functioning Catalytic convertor - These are £600 to £469 which is the cheapest in the UK. They ONLY COST £60 in Brazil!

My main concern in replacing the CAT is that the Lambda sesnor was covered with soot & carbon so unless its blocked (causing blow back) it is rich from the engine pre-cat as the lambda is the last sensor. CAT function is hard to test.

Still to test - 
Measure CAT function - Temp before and after CAT.

3. Exhaust Blockage / Restricted / Leaking

A block or restricted exhaust causes issues. It basically causes the exhaust to recirculate in the combustion and even inlet manifolds. This could be the cause but ran a vacuum test on the inlet (common and useful technique for Air leaks and back pressure) this showed a typical "normal" response.

Leaking exhaust can cause issues but I cannot find any leaks or holes. Exhaust is expensive to replace so will leave this until later. 

Still to test - 
Will try the rag up the exhaust to see if it stalls and what it looks like with a restricted exhaust.

Will remove CAT & Both boxes and have a look for blockages. Need to order gaskets, new bolts & exhaust sealant

4. MAP Sensor

MAP sensor is the prime sensor for the amount of fuel to inject into the engine. If it was reading an incorrect level it "could" be the reason to run too rich. No fault codes so in range but could be giving a false reading.

I don't have the VCDS version with MAP pressure readings but plan to check against gauge.

I have been looking for the MAP sensor. Parts from Bosch are typically around £100 so not going replace this unless I am sure.

Still to test -
Measure pressure with gauge and check MAP output voltage with voltmeter.

Purchase VCDS to get access to Measurement blocks 0000 which has MAP pressure readings

5. Coolant Sensor (Oil Temperature)

The engine runs rich until up to temperature. So if faulty will constant run in open loop and rich.

Checked with Multimeter and also Logged data with VCDS and its seems to be correct values and heats up to switch to closed loop once warm. No fault codes. So not coolant sensor at fault.

One thing to note is that the oil temp takes ages to switch to closed loop (approx 80oC) short journeys could be causing to run rich for ages. I am sure the hotter climate in Brazil it does not take so long. On UK days takes a far few miles to get to 80oC.

Still to test -
Check coolant vs temp response. 

Maybe include an extra resistance to make value read 10oC hotter so goes into closed loop earlier (great for shorter journeys)

6. Dirty Injectors / Stuck Fuel Injector

If an injector gets stuck on. The engine will over fuel and run rich. The engine will sense this at lambda and I would expect the on pulse duration to be very short as the engine tries to lean out. I did not see this on the VCDS logs.

Used carb cleaner on inlet throttle body and down to injectors. Also added a bottle of Redex injector cleaner.

Still to Test - 
Test using a fuel pressure gauge (should stay at pressure for long time when pump is off - leaky injector will cause rapid pressure decay) need to restrict fuel back to pump

To test I will need to check the spray pattern (remove and spray into a jar)

7. Fuel Pressure Regulator / Too High Fuel Pressure

If the fuel pressure is too great (pump) or faulty fuel pressure regulator causing too higher pressure. This will cause the injector to over fuel so the ECU thinks its pulsed the correct amount but mixture is too rich so will back off pulse duration to lean out mixture.

I have check the pulse widths from a good emissions run done last year and after emissions failure and they seem the same nothing indicates an issue. However I have been reading about short term and long term trims. This should show if its and issue BUT I cannot find them in the VCDS log.

Checked the vacuum line to the pressure regulator for fuel (indicates a leaking regulator seal) and found none so suspect its good

Still to Test - 
Test using a fuel pressure gauge not sure what the actual fuel pressure should be but expect regulator should return pressure back to fuel tank.

Replace fuel filter and see if its causing a higher pressure. Blocked filter will cause higher pressure but reduced flow.

8. Blocked Air filter

Block air filter will cause lack of air and therefore rich mixture. Inspected the air filter and looks clean.

Still to Test - 
Will replace air filter as part of next service

9. Faulty Lambda Sensor

Faulty Lambda sensor will cause over or under fueling. The ECU should report a fault code if lambda is at fault.Replaced the Lambda sensor anyway, so its not the sensor.

Still to Test - 
Will check with scope the Lambda signal and see if the ECU is getting a lean or rich mixture from its voltage response.

10. Faulty PCV Breather

I have noticed from the HC levels of zero this could indicate a blocked or non functional crankcase breather valve.

I have noticed before that the breather does not seem to be working and pipes are always blocked with the "gunk" " Mayonnaise" from the oil / water mix. This is common place with air cooled engines and short journeys never burning off the water.

I have no managed to source a new PCV valve (211 129 101) took me ages to find one finally got one from The Netherlands.

When fitting it I noticed that all the other Brazilian engines had the breather fitted vertically. Mine was always fitted horizontally and therefore incorrect.

Now fitted a new one the right way round! Not much difference but I am sure its better and working now. Not sure what effect it will have on emissions.

11. Tappet Adjustment

The tappets will have an effect on emissions. So reset and they did not make any difference to emissions.

12. Charcoal Valve

The engine uses the fuel tank breather re-circulation via a charcoal canister and valve. This then adds an extra breather fuel back to be burnt. This is regulated via the ECU once the engine is warmed up.

This could cause an extra over fueling and rich mixture if always on. The VCDS logs show that this is functioning BUT a faulty valve could cause this to be always on but this should be measured at Lambda sensor and adjusted for

Still to Test - 
Test the canister valve to see if it functions on demand.

So in summary I have done the following:

  1. New Lambda Sensor 
  2. Carb Cleaner / Redex
  3. New & correct fitting PCV Valve
  4. Replaced Vacuum hoses 
  5. Measured Inlet Manifold Vacuum - Looks normal no leak or restriction
  6. Tappet Adjustment
  7. Measured coolant, throttle, injector, valves etc nominal resistance - All within specifications

I have to do the following:

  1. Clear fault code from ECU (TPS zero offset)
  2. Test for blocked CAT - Block exhaust check Vacuum / Remove inspect
  3. Measure CAT temperatures
  4. Test Coolant Sensor - Resistance Vs Temp
  5. Measure MAP Sensor Response - VCDS & Output Vs vacuum gauge
  6. Fuel Pressure - Leaky / Stuck injector / Fuel Filter replace
  7. Measure Lambda response
  8. Test Charcoal valve - Power & Check



Tuesday, 26 May 2015

Great Parts Diagram Website


I have found a great parts diagram database. Great for most models but the VW section has all diagram which for the Type 2 seem to date back to 1968.

http://www.partsbase.org/vw/

Great for checking parts and also seeing the wonderful diagrams created by VW.

Sunday, 15 February 2015

VW Camper Van Ownership - Are you suitable?

I have been wanting to write this article after seeing the following VW advert.



There are a lot of VW camper van buyers guides out there BUT not to check if YOU are suitable for ownership.

There are many out there who have the money to buy a Classic Type 2 or Brazilian and expect that they are modern cars as they are new or cost in excess of £20K.

They then spend time moaning about the reliability, lack of speed, lack of power steering etc. from a camper van which design has basically not changed since the 1960-70s.

Maybe this suitability test is to check if your suitable.

http://t2bay.blogspot.co.uk/p/vw-campervan-ownership-are-you-suitable.html

PLEASE remember this is just for fun! Please don't take offence!

Monday, 2 February 2015

Updated T2c Kombi Service Manual


I have been trying to update the layout and style of the service manual.

I have converted each page to a image. This allows the easy scroll down through the pages.

It also allows you to click (left) on a page and the whole pages is enlarged with a small thumbnail view at the bottom.

It works best on a PC but I am sure it should be good for Mobiles, tablets etc.

The manual is accessible using the link on the pages on the right.

Thanks

Sunday, 3 August 2014

VW T2c Kombi Front Beam Restoration

After inspecting my front beam I have found a large amount of surface rust on my front beam. The factory paint was long gone and the only protection came from the oozing grease around the beam greasing points and general crud.

So I had set aside some time to clean strip and treat the surface rust before applying paint. This was all done while the beam was fitted to the van. It would have been better to drop the front beam but decided to do place as there was no other reason to drop the front beam.

At the same time it was decided to remove and replace the anti roll bar as one of the clamps had come loose and was an advisory at the last MOT.

This procedure only details the renovation and painting of the front beam. I did not cover the renovation of the king & link pin or the suspension arms. These will be tackled in a later process. It also does not cover the routine greasing of the suspension as this will be also covered in a later procedure.

Tools / Materials Required:

Trolley Jack with suitable lifting mount
x2 Axle Stands
x4 Wheel chocks
19mm Socket & Breaker Bar for wheels
Jenolite Rust Killer
Zinc 182 ANti Rust Primer
Matt Black Paint
Selection of paint removal tools (wire bushes, sandpaper etc)
Electric drill or angle grinder with suitable paint removal tools
PPE - Safety Glasses & dust mask and gloves

Safety Note - Always ensure the vehicle is supported on suitable axle stands. PPE safety equipment is required. Only attempt if you are competent and at your own risk.

Lifting Procedure:

1. Park the van on a flat hard level surface.
2. Apply the hand brake
3. Chock the rear wheels on both both sides
4. Remove front hub caps. Using the 19mm socket & breaker bar loosen the front 5 wheel nuts. Only loosen do not fully remove.
5. Mount suitable lifting mount to trolley jack and locate the jack under the front beam in the center. Ensure trolley jack is positioned to lift the front evenly. I use the front lower beam just behind the steering swivel pin box fitted to the front beam.



6. Once the trolley jack has been suitable positioned and mounting block is located (mounting block shown here is a garage lifting jacking rubber block found on e-bay) gentle raise the vehicle until the front wheels are off the ground by more than 1-2 inches.
7. Position your axle stands so they are evenly spaced in from the outer edges of the beam. Ensure your axle stands do not clash with the two grease nipples mounted on the lower tube. Ensure that you are not completely under the van when lifted with just the jack.
8. Raise the axle stands and remember that as the van is lowered the arc of the trolley jack will mean the starting position is not always the final lowered position.
9. Low the jack gently and slowly constantly checking and adjusting the position of the axle stands to ensure good even contact with the lower tube.
10. Once the jack is fully lowered ensure that the van is securely on the axle stands. Give the van a good push and shake and confirm that the van is totally secure and stable.
11. Now remove the front wheels.
12. Place plastic bags over the front brake discs and outer suspension components to prevent debris and grease from getting on the brakes.

Front Beam Inspection:

1. Inspect the front beam outer plates in the wheel arches. Removing an excess grease from around the arms. Just clean at this stage using a solvent & rags to remove as much dirt & grease. Don't start using any abrasive products yet as the grease and dirt will just clog them up.



At this point I removed the Anti roll bar as I needed to replace the clamps and also paint the bar. 2. Now Inspect and clean the upper and lower torsion tubes. Again just using solvent and rags to remove as much dirt and grease as possible.





3. Once all parts are clean and grease free. Start removing as much paint and any remaining dirt. 

Caution - Do not excessively clean or use abrasive products near moving parts, seals and grease nipples. These will get damage and allow dirt to enter.







Using the abrasive tools try to remove as much surface rust as possible. Once removed clean up the surfaces with suitable solvent.






4. Now treat any rust with suitable rust killer. I use and recommend using Jenolite as its easy to paint on and drys quickly.
5. Once rust as been treated then prime the front beam. I use and recommend Zinc 182 anti-rust primer. Paint this on by brush as its better to avoid painting other components such as steering arms and cables.








6. Allow to dry (>6 hours or overnight) and repeat any areas missed.

7. Now paint the first coat of Black Paint. I choose a Matt Black paint by Tetrosyl. Apply first coat by brush.



I also painted the lower arm as I was replacing the anti-roll bat & clamps. The outer suspension and upper arm will be done at a later date.




8. Allow first coat to dry. Apply the second top coat.


Before
During
   After

Before
After

Before
   After


9. Once completed and paint has dried refit wheels and tighten as much as possible.
10. Place trolley jack under lifting point and raise until vehicle is off the axle stands.
11. Remove axle stands and gently lower vehicle until on the ground.
12. Remove jack and tighten wheel nuts using 19mm socket and breaker bar.
13. Refit hub caps.
14. Paint the areas left where the axle stands where located.

Once completed it is advisable to grease the front suspension. See separate procedure.


Kombi Wheel Arch Rust Repair

Common rust trap on T2 Bays. Water from the road tire rotation constantly spraying onto the underside of the front seats. Any damage or stop chips in the under seal leads to corrosion.

Rust noticed around the drivers side seat runners and seat belt mount.

 
Only slight surface rust but somethings going on underneath.

Closer inspection seems that under seal has had quite a but of wear. Instead of just covering it up I thought I would take a closer look under the seal.

Warning - Removal of under seal is BEST done totally dry - Do not foolishly attempt (as I did first time) to remove with any form of solvent, petrol etc. It won't won't work and makes a horrible mess.




After a lot of scraping of under seal I managed to start to revel the original paintwork. There is a strange 3 layer plate around the seat runner. It was sealed with just silicone sealant and the water had got behind.

After a lot more scraping and then using a multiple of wire brushes and having found a brillo pad style disc had the best effect.


Back to bare metal. Treated with Jenolite rust killer. Then primed with Zinc 182 Primer.


Once Primed applied 2 coats of Hammerite white.


Then applied many thick coats of under seal.


Check and renewed the passenger side wheel arch. No sign of rust on the passenger side so just over coated the under seal.