Hi Joe,
Re the VSR: yep this is definately a problem, especially for a PI with the
higher compression ratio (and therefore cylinder temperatures). The lower
compression 2000TC's and 2.5 TC's don't seem to have the same trouble
unless they are well and truly thrashed hard. The VSR is a function of how
hard the engine works and becomes significant over around 3000 RPM (so
Grandpa driving is 2000 auto is not as like to have problems as the boy
racer in the MOD suped up PI - I fit in somewhere between the two).
There are a number of tin type devices which have been offered for sale
which claim to leach tin into the fuel to prevent VSR. These basically
don't work. If you aren't going to fit hardened valve seats, then use
valvemaster or similar. The only problem with valvemaster is it has a lot
of kerosene in it which fouls the plugs round town.
The early PI's like mine and yours have the larger inlet valves and the
advice I have been given is not to fit hardened seats on the grounds they
are an interference fit and if the motor overheats, the seats may well drop
out. Someone else may have some advice on this...
The later PI's (facelift) have smaller valves and can be fitted with
hardened valve seats. There was some information going around that these
already had hardened seats which fits with my experience. I ran a 1975
facelift PI for around 30,000 km on unleaded with no additive and
experienced no VSR.
I replaced the o-rings with standard ones from the local engineering outfit
(Pikyl) and they seem to work just fine (been in there 3 years now...).
There is a special seal between the fuel pump and the motor which cost
around $35 NZ. I had no problem with the banjos on the metering unit or the
little rubber seals where the banjos screw into in the metering unit. I
understand most of these seals are available from Rimmers or similar
outfits in the UK.
I don't have a circuit for the O2 sensor, but if you do a search on DIY
EFI, I'm sure you will find someone who has.
Hope this is helpful.
Cheers
Bernard
'71 PI (I've stopped it dripping oil at last!!)
'73 TR6 PI
At 07:23 9/06/00 +1000, Santamaria, Joseph (Joseph) wrote:
>Hi Bernard, thanks for the info.
>
>How did you go with valve seat recession,pinging etc on the PI's with
>unleaded and where did you source new rubbers for the injection.
>
>Also do you have any circuits to drive the leaded sensor and a display(meter
>etc) to display mixture or are there bosch units or others as full mixture
>display kits.
>
>Thanks for any help you can give in Advance
>Joe Santamaria
>* Lucent Technologies Australia Pty Ltd
>Call Centre Consultant
>Lucent Technologies CRM Professional Services
>*Tel: +61 2 93529287
>*Fax: +61 2 93529287
>* mailto:jsantamaria@lucent.com
>
>
>
>-----Original Message-----
>From: Bernard Robbins [mailto:brobbins@wlg.nec.co.nz]
>Sent: Friday, 9 June 2000 5:32
>To: Santamaria, Joseph (Joseph); William Whitmoyer;
>6pack@autox.team.net; Stag Digest
>Subject: RE: leaded fuel O2 sensor
>
>
>Hi Joe,
>
>Yep, there are special leaded fuel versions available from bosche. I
>understand they are significantly more expensive than the unleaded type.
>The local repco should be able to help.
>
>You are very lucky still having leaded fuel. NZ lost it several years ago
>as a result of the local pressure groups (silly thing is we have replaced
>the lead with other wonderful poisons such as benzene and tolulene and lots
>of it!).
>
>If Aussie does go to unleaded, be careful with your PI. Straight unleaded
>fuel is fine as is straight leaded fuel. However, I found that the mixture
>of leaded and unleaded (by the petrol stations during the changeover time)
>melted all the rubber between the fuel pump and injectors (that's a lot of
>o-rings!!)
>
>Cheers
>Bernard
>
>'71 PI (snap)
>'73 TR6 PI
>
>
>At 05:25 9/06/00 +1000, Santamaria, Joseph (Joseph) wrote:
>>Does anyone one know of an electronic air/fuel ratio sensor that is able to
>>be used on leaded fuel. In Australia leaded is still quite available and I
>>use it in my 2500PI and Stag and would love to use this easy method to
>>monitor the mixture.
>>
>>Cheers
>>
>>76 Stag
>>71 2500PI Sedan
>>
>>Joe Santamaria
>>* Lucent Technologies Australia Pty Ltd
>>Call Centre Consultant
>>Lucent Technologies CRM Professional Services
>>*Tel: +61 2 93529287
>>*Fax: +61 2 93529287
>>* mailto:jsantamaria@lucent.com
>>
>>
>>
>>-----Original Message-----
>>From: William Whitmoyer [mailto:wwhitmoyer@samsonite.net]
>>Sent: Thursday, 8 June 2000 6:02
>>To: 6pack@autox.team.net
>>Subject: Tim's Idle Mixture
>>
>>
>>When I first set-up my 2 stock carbs, I had success using a
>>Colortune...which lets you see (roughly) what the mixture is in each
>>cylinder.
>>
>>
>>
>>Date: Tue, 6 Jun 2000 21:45:52 -0700 (PDT)
>>From: tr6taylor@webtv.net (Sally or Dick Taylor)
>>Subject: Re: Idle mixture
>>
>>Tim---I don't know if I can help or not, but let's go over a few
>>things..First, you paid $ to have an air/fuel monitor. Situations such
>>as you described are exactly why they are sold to after market users.
>>Get the blasted thing connected, for starters.
>>Having only one sensor sending info about three carburetor mixes won't
>>make it easy to sort out what it's telling the monitor. As you must
>>know, the exhaust could now be a mixture of two rich carbs and one lean
>>one, for example. You'll need to look at your sparkplugs to make sure of
>>even coloring. Anytime one goes it alone when modifying an engine can
>>find themselves wondering if the did the right thing! OK, enough with
>>the philosophy....... (cut)
>>
>>Dick T.
>>
>>William Whitmoyer
>>69 TR6
>>90 BMW iX
>>91 CRX Si
>>
>>
>Regards
>
>
>Bernard Robbins
>
>NEC New Zealand Ltd
>Network Solutions
>P.O. Box 1936
>Wellington
>
>Ph (04) 381 6274
>fax (04) 381 6284
>email brobbins@wlg.nec.co.nz
>
>
>
Regards
Bernard Robbins
NEC New Zealand Ltd
Network Solutions
P.O. Box 1936
Wellington
Ph (04) 381 6274
fax (04) 381 6284
email brobbins@wlg.nec.co.nz
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