Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[The Cambelt Kid]

Hi Guys,
Finally got my V6 on LPG yesterday, although I did have a few issues to start with, one of which was the power into the LPG ECU, which I will rectify very soon.  One of the other problems which I am quite concerned about is the guy at Micromise (LPG kit supplier) noticed that the injector timing on one of the banks was slightly different to the other, from memory he said that while ticking over on petrol he noticed that one bank was fluctuating around 2.5 milliseconds and the other 2.8/2.9, indicating that the mixture on one bank was different to the other.

Since I bought the car back in April I have noticed a very slight decrease in performance and an increase in petrol consumption, also not forgetting that the engine doesn’t seem to idle as smoothly or quietly as the 3.2 I heard ticking over yesterday.  It has made me think that something isn’t quite right.
One thing that did pass my mind was the idea that the left and right hand banks might be slightly out of sync?  I recall in MDTM’s cambelt DVD that it is possible to get the two heads out of sync.  What are the symptoms of this?

Does this make any sense at all as I am becoming increasingly worried that I could be damaging one bank on the engine by running a lean/rich mixture.
Any help on this would be great as I am starting to get out of my ‘diagnostic’ depth on the V6..

Regards

[Kevin Wood]

Could be a valve timing difference between the two banks. Only way to find out is to take off the cam belt cover and check the timing.

They also draw their air through different throttles when the rear multiram is closed (should be open at idle though).

Different airflow through each bank for whatever reason means the ECU will trim the fuel differently for each bank to maintain the correct mixture. Maybe the trim got upset when running on LPG and isn't back to normal on petrol?

It doesn't sound a huge difference, TBH, but if there has been a performance loss then it's worth checking for air leaks, exhaust manifold blows, clean out the throttle body and ICV, vacuum hose routing, etc.

 
Kevin

[The Cambelt Kid]

Nice one Kevin, thanks for the input.

I think i will start with the cam timing first as this sounds more likely.  Just to bring you in the picture - the car, while on petrol before the LPG install has the same symptoms, so i would guess that it isn't the LPG for now.

I will have a look at the BELT this w/end if i et chance, but i'll be keeping an eye out for any other possible problems posted on here.

Cheers

[Martin_1962]

Does the kit use a Lambda probe?

My thoughts are on the cam timing also.

However how are the spark plugs?

[The Cambelt Kid]

Hi Martin,

Yes the kit does have x2 wires for the lambas.  They are not connected at the moment as it wasn't a need to have, more of a nice to have, well until now that is!

The plugs are 3k old, rocker seals recently replaced but not tourque'd up with torque wrench, I did this by hand as I didn't have a TW.  There are no oil leaks near the rockers, so I guess this is ok.

The EML came on after the first 80 miles on LPG so maybe the LPG is highlighting any running issues the car might have.

I'm glad people are re-enforcing my theory of cam timing, it's the only logical thing it could be at the moment.

Cheers
Marc

[The Cambelt Kid]

am i correct in thinking that i can't do the paperclip test on a 52 plate?
 

[Martin_1962]

Sounds like it - no paper clip test though.

I was wondering if one lambda was connected causing odd readings.

Plugs seem OK - might be worth pulling one to have a look.

For now though lets say cam timing is suspect 1

[The Cambelt Kid]

The lambda wires from the LPG ECU are only used to read voltages for diags and are not (as far as i am aware) used to calculate to aid LPG mixture.  The LPG ECU calculates injector timings from the Vx injectors only.  So when i was configuring the LPG ECU i could see that the LPG ECU was making the same injector timing offset as the Vx injectors.

I will post up a pic shortly to show you.

Cheers
M

[The Cambelt Kid]

here's my proof that i'm not going mad  

[JamesV6CDX]

Very well done on the LPG conversion. What are you doing about certification? I want to DIY LPG mine, but if I tell my insurance company, Directline - they will void my insurance if it's done DIY!

On to your issue, I strongly suspect cam timing is a few degrees out. It's definately the first thing to check, and won't take you long. I'm sure one of our Notts/Derby members could lend you a kit.

Aditionally, if you're unsure of cambelt/waterpump history, then this is a prime time to change it all!

If you do, though, check the timing before you take it apart, to satisfy yourself whether it was out, or not....

[Martin_1962]

Very well done on the LPG conversion. What are you doing about certification? I want to DIY LPG mine, but if I tell my insurance company, Directline - they will void my insurance if it's done DIY!

On to your issue, I strongly suspect cam timing is a few degrees out. It's definately the first thing to check, and won't take you long. I'm sure one of our Notts/Derby members could lend you a kit.

Aditionally, if you're unsure of cambelt/waterpump history, then this is a prime time to change it all!

If you do, though, check the timing before you take it apart, to satisfy yourself whether it was out, or not....

You just hand them a certificate with the name of the inspection company on it.

[The Cambelt Kid]

Hi Guys,

When you say a few deg's out, I take it we are not talking no of teeth on the belt?  I have never changed a V6 belt before but as I understand it is possible to time both heads with the adjustment of a sprocket??

I will watch the cam DVD and verify my idea and then I will take a look over the w/end.

As for the LPG certificate - I installed the kit to a high standard on both of my cars and took the cars to Essex for the kit supplier to check over and verify its integrity.  Once he's happy that it's of good standard and safe he'll then issue a certificate.  Obviously he wanted his palm crossing with silver, well about 75 notes for 3hours pratting about and the certificate!  The insurance only need to know if it’s got an LPGA certificate, which both of mine now have.

If you are interested in doing it yourself then I highly recommend the supplier of my kit – Micromise http://www.autogas-micromise.com/ He has provided no end of telephone support and was available pretty much every day of the week.  He followed me through the install on both of my cars from start to finish.  He is also an LPGA certified installer and has done many installs himself, although he now employs engineers to do the installs while he concentrates on R+D.

I do plan to fabricate a how2 for the install, with step by step instructions, although this will be on the back burner for the time being.

[The Cambelt Kid]

In fact, if what i think is the case - can a few deg's out cause any damage if ran for 5k miles?  

[Marks DTM Calib]

They use engineers for the installs and not fitters......must be very expensive!

I have a locking kit if you need one with the timing gauge.

[The Cambelt Kid]

Well i say 'engineers' i meant to say fitters/installers.  My dad's a Royces engineer so i don't think they are experienced to that sort of standard, after all i fitted mine and i'm not an enginner.  I only dabble with computers for a living, that and surfing the t'interweb all day  


I think i'll take you up on that offer Mark, i'll PM you as and when.

Cheers
M