WTF!!!!!

 

did a compression test on number 6 and it came back almost zero, added some oil, still zero must be a valve or the headgasket , im not getting any smoke at all, just waiting for my mechanic to call back...

 

Having a bit of a nightmare at the mo :(

 

Looks like its coming apart again. :(

I've no idea what the compression figures should be, but i know all mine averaged bewteen 165-175 on a rebuld that was over 4 years old.

Topass! ( sorry mark couldn't resist, see jimmys post, lol) do you know what the average correct figure should be ?

 

Anyway, as said before still sometime before going back to scotts to hopefully eliminate any other possible causes. Simply because everything else needs to be bob on before you can go down the road of a faulty part/or rebuild.

smithy

Would the fact i have a thicker head gasket give me a lower comp reading across all bores? i think it would yes?

so i suppose 140-150psi is a good reading for a fresh build which hasnt had much time to bed in? and 200psi wet is a lot?

 

Right well the new ecu arrives 2mow, so thats the next step, i will also do another comp test on number 6 2mow to see if it has improved again somehow!!!!

Its all very confusing, or mysterious!!

Edited July 18, 200817 yr by j1mmytt

The golden rule of mechanics is to always fix what you know is wrong and you know the ecu is wrong, even though you claim your socketing was good ;)

 

Go from there, jfyi it wouldn't give blue smoke if you burnt a valve out and you would still have lo compression!

it will all come out in the wash mate. even I can see the light

The golden rule of mechanics is to always fix what you know is wrong and you know the ecu is wrong, even though you claim your socketing was good ;)

 

Go from there, jfyi it wouldn't give blue smoke if you burnt a valve out and you would still have lo compression!

 

So if it does happen to be a duff valve would that explain the rough running maybe?

 

Would a broken or faulty valve spring cause low compression?

So if it does happen to be a duff valve would that explain the rough running maybe?

 

Would a broken or faulty valve spring cause low compression?

 

If one of the springs has broken then you're almost certainly going to loose compression.

 

I think the lifters can cause a valve to hang open too if it doesn't compress properly.

 

Also, if there's too much play in the valve guide then, again, the valve won't be seating properly on its return and cause a small drop in compression. (But certainly not to the extent that you've observed).

 

One last thing - IF it was running lean on the suspect cylinder - you may have burnt and pitted the exhaust valve seats.... (unlikely though as I think pistons are more likely to hole before a valve seat gives up!)

 

I think for now all this talk is just one big guessing game until the head is off. to reveal the true cause.

 

I hope for your wallets and your sanity's sake it's something simple!!

If one of the springs has broken then you're almost certainly going to loose compression.

 

I think the lifters can cause a valve to hang open too if it doesn't compress properly.

 

Also, if there's too much play in the valve guide then, again, the valve won't be seating properly on its return and cause a small drop in compression. (But certainly not to the extent that you've observed).

 

One last thing - IF it was running lean on the suspect cylinder - you may have burnt and pitted the exhaust valve seats.... (unlikely though as I think pistons are more likely to hole before a valve seat gives up!)

 

I think for now all this talk is just one big guessing game until the head is off. to reveal the true cause.

 

I hope for your wallets and your sanity's sake it's something simple!!

 

I hope so too, but there is still hope as its not missfiring anymore and seems to be running better than ever now ive just fitted the new ecu. so fingers crossed maybe a lifter was stuck or something.

I hope so too, but there is still hope as its not missfiring anymore and seems to be running better than ever now ive just fitted the new ecu. so fingers crossed maybe a lifter was stuck or something.

 

thats good news mate:) as the car runs better you better start deleting posts:rofl::D

thats good news mate:) as the car runs better you better start deleting posts:rofl::D

 

Im still to do a compression test again. I just dont understand how the compression can suddenly change how and when it feels like it..... must be a stuck lifter, would it make sense to say coz they are reconned they need wearing in to move freely or something...

i have known hydraulic tappets to jack open & cause lack of compression due to sticking oil pressure relief valves causing excessivly high oil pressure. just a thought

I hope so too, but there is still hope as its not missfiring anymore and seems to be running better than ever now ive just fitted the new ecu. so fingers crossed maybe a lifter was stuck or something.

 

 

That's because you needed an expertly socketed ECU ! ;)

That's because you needed an expertly socketed ECU ! ;)

 

:x: :bow:

 

Its becasue i had to socket it twice due to being a plum. first time round was a winner, second nope.

 

easiest way would be to cut old chip out from the pins then solder wick everything out individually?

:x: :bow:

 

Its becasue i had to socket it twice due to being a plum. first time round was a winner, second nope.

 

easiest way would be to cut old chip out from the pins then solder wick everything out individually?

 

In my experience re-socketing is an absolute bitch and to be avoided at all costs. Solder wick is a waste of time - need a sucker.

In my experience re-socketing is an absolute bitch and to be avoided at all costs. Solder wick is a waste of time - need a sucker.

 

Right il remember that for next time. where to buy a sucker then?

False alarm its still running rich and idling up and down... god i give up.

Look for an air leak. Did you get all the vacumn pipes in the right place ?

Just spoke to him a little while agao and he's gone to work now. There were no boost leeks as fair as we could tell. No idea if all the pipes were in the right places :(

 

Vijay

Look for an air leak. Did you get all the vacumn pipes in the right place ?

 

Is there a way to test if all the pipes are on correctly?

 

By the way some of the pcv valve pipes have the ristrictors removed, not sure if this makes a difference as it was running fine before the build like that.

 

Also i still have no reading from the left o2 sensor even with new ecu :(

 

Hopefully vjay will be so kind as to do another conzult with me :)

 

Why the hell would i be getting zero reading from the o2 ecu wire/pin? did i mention that someone has tampered with the ecu wiring, there seems to be some black tape around half a dozen ecu wires, possibly an old boost controller there from a previous owner?

Maybe there is a bad earth somewhere or an earth someone has forgotten to replace?

 

Just a few suggestions to tickle yours brains.

I thought you said there was no output from the ecu on that O2 sensor, so you are now saying it's the wiring? But one O2 sensor not working will not cause your rough running problem!

 

Did the pcv pipes come with the restrictors removed or did you remove them and where they put on in the correct location? It is all pretty academic as the pcv pipes having their restrictors removed will not make you engine overfuel and run rough!

 

There is now way to test the pipework, you have to manually look to check their physical location!

I thought you said there was no output from the ecu on that O2 sensor, so you are now saying it's the wiring? But one O2 sensor not working will not cause your rough running problem!

 

Did the pcv pipes come with the restrictors removed or did you remove them and where they put on in the correct location? It is all pretty academic as the pcv pipes having their restrictors removed will not make you engine overfuel and run rough!

 

There is now way to test the pipework, you have to manually look to check their physical location!

 

No im not saying its the wiring, im saying im still not getting any reading from the wire straight from the ecu or the pin. i was also not geting a reading from the conzult. maybe vjay will visit later for another conzult, if the ecu still hangs this will be confusing.

 

The golden rule of mechanics is to always fix what you know is wrong!

o2 is wrong dude :D just doing as the wise men say.

 

 

 

Theres no way i can tell if pipes are on the correct way, will need another zed pakred next to it to tell :(

 

 

There is some good news though.

Did yet another compression test yesterday and im getting 150psi on number 6 again!!!! and all the rest are fine :D would that point to a sticky lifter?

Edited July 20, 200817 yr by j1mmytt

Well really good to see things are actually getting better, albeit slowly ;)

IMO if the ECU does not register one of the 02 sensors, it will compensate and add excess fuel, not much, but enough to be running rich under non load conditions.

If you have a look in the meetings section and see who lives closest to you and now the car is running much better, maybe pop round and have a look to compare engine bays. Bare in mind you have removed certain pipes, it's how it's done what could be important.

Still think your problems are just a couple of little niggly ones, which by process of elimination, will solve it all :p

smithy

Well really good to see things are actually getting better, albeit slowly ;)

IMO if the ECU does not register one of the 02 sensors, it will compensate and add excess fuel, not much, but enough to be running rich under non load conditions.

If you have a look in the meetings section and see who lives closest to you and now the car is running much better, maybe pop round and have a look to compare engine bays. Bare in mind you have removed certain pipes, it's how it's done what could be important.

Still think your problems are just a couple of little niggly ones, which by process of elimination, will solve it all :p

smithy

 

Better slightly, i was so sure it was a dodgy ecu ah well :(

moving on swiftly then.....

 

Does anyone know why i wouldnt get a volt reading from the left o2 sensor straight from the ecu?

I think I know what the problem is Jimmy!

 

 

Your zed has Baron Munchausen syndrome :D

Does anyone know why i wouldnt get a volt reading from the left o2 sensor straight from the ecu?

 

Is the sensor actually working?

(Sorry if that answer is somewhere in this thread ;))

Is the sensor actually working?

(Sorry if that answer is somewhere in this thread ;))

 

I cant tell if its working coz there is no reading on the conzult or the wire all the way to the ecu pin??? i just took a pic of the tampered wires and a connector which is unplugged. gimme a sec.