few problems

[dubberjim 0]

hi all

ive just completed my mk2 vr conversion and have a few problems.

first on its was running fine reving nicely and pulling like a train. then a plasic burning smell turnned out to be the servo vacume pipe on the manifold replaced that but the engine is not running right since not sure if it is connected or not but uses loads of fuel £45 to do 180 miles. under load its good but wont idle just hunts and if you try to accelerate gently it judders like made popping and farting. i have a new maf on its way think it might be this does anyone else have any ideas?

second. i have an oil leak ive stripped the engine down inlet off upper chain cover off the leak seems to be coming from the top of the lower chain cover front edge. i think it might be just the head gasket not sealed properly i used plenty of sealent when i pout the top cover back on but still leaking. is it worth replacing the head gasket or should i take off the lower cover aswell and re seal that to? also what sealent? when i do the head can i use the same bolts? they have done 200 miles max not got over hot.

last thing i have no lamba sensor this may have something to do with all the fuel used,where does the lamba probe plug in? its an obd2 engine and loom. anyone know where to get a good one cheap? also the boss to weld to the exhaust?

any help would be awesome cheers

[legvw 0]

I think your right about the lambda, i think its causing the running problems. The plug should be down by the rear left engine mount, and the bung is just after the downpipe flange, before the cat.

What sealant are you using to seal the oil leak? Are you cleaning the faces properly, with brake cleaner?

[dubberjim 0]

there is not hole for the lamba as im using 6 branch and have made my own de cat so ill need a boss welded on. i cant find where it plugs into though anyone know how many pins the plug has or the colours of the wires?

yes i cleaned it properly when i took the to chain cover off

the head gasket seems to have been pushed out of where the 2 covers meet.

[legvw 0]

If the gaskets been pushed out i'd say its been over-tightend.

You can buy the bungs fron Jetex, i think the lambda has 4 wires, brown white yellow red, i think, but thats just off the top of me head!

[dubberjim 0]

cheers mate.

it could only be over tightened by the 2 bolts that go in from the undeside then? do they have a toqure setting?

[legvw 0]

Yes they do, but for the life of me a can't remember, its not that tight though.

[dubberjim 0]

just a quick one, are there 2 lamba probs? one for each bank of 3? and are they the big oval plugs one each side of the bay?

[AJmk2 2]

There are two lambda sensors but you only need to run one.

The ecu doesnt know how your engine is running without the sensor in, surprised you can even drive it like it, will be night and day difference once you have one in.

Mine is fitted in my decat.

[craggsy 91]

Im confused....since when has the VR had 2 lambdas?

There is only a pre-cat lambda, might be 2 if running a wideband sensor

[dubberjim 0]

so if there is 2? is one per and one post cat?

i have not can so im guessing ill just need the pre one. does anyoine have a picute of the plug it goes into? cheers

[Scott 0]

I have no lambda, get 33.5mpg at a steady 65mph. My MAF caused running probs, but the lambda does not, mines obd1 however.

[dubberjim 0]

still not running.ive taken the MAF off and cleaned it

it seems to tick over a little high when it does actually tick over. most of the time it just hunts and farts. you can hear a clicking when it seems to miss so i had a look and its coming from the relay that hangs down by the fuse box with the 53 on it.

also noticed some smoke coming from the manifold so had a look and there is oil dripping from the pipe throttle body side of the maf. ive taken it off and its filthy so is the throttle body im guessing thats not right? seems to be a lot of oil. also i have noticed there some sort of valve off the breather pipe from the rocker then after that an elec connector but the thing it connects to has no elec pins inside. any ideas?

ive taken all the pipes off from the rocker MAF and to the throttle body and cleaned them all. they were pretty minging also cleaned the throttle body as far as i can but no difference.

[rigs 0]

The breather thing isn't needed and can be ignored on a mk2.

Try running the car with the maf unplugged. If it improves the maf might be dead or some wiring fault there.

My one had a faulty throttle position sensor that caused the same as your "it idles and runs at full throttle but pops and bangs at part throttle" thing. Try unplugging it... if it it runs better replace the sensor.

A VR6 should run normally (as in idle smoothly and rev freely) with all of the extra sensors but the crank sensor unplugged assuming normal operation of the basic stuff (coilpack, spark plugs, injectors etc...) so you can try unplugging things and see if it makes a difference.

A mis-reading sensor will cause it to run worse than having no sensor at all!

[dubberjim 0]

cheers tried the throttle position sensor and it does smooth out. how much was yours is it a vw only thing?