My 1st ever Triumph (Mk2 2500Pi)

[RobPearce]

The cap spec depends on age. Mk1 cars and early Mk2s has the 7PSI (0.5bar) cap but later cars got the 13PSI (0.9bar) one. I don't think there were any changes to the cooling system, other than possibly a higher thermostat temperature, so you can probably get away with either. The 0.5bar puts less strain on old and tired hoses and radiators, though.

[frenchiemk2]

right.

Any advice for cooling fluid as they preconized "rain water", i think there are very perfo cooling fluids nowadays, but maybe too agressive for old engine?

[frenchiemk2]

And also for the battery specs Haynes mention 12v 58ampere/hour

But which amperes value ?

In order not to damage the electric components.

Thanks

[RobPearce]

For coolant I use boiled water (we live in a hard water area and boiling removes some of that) mixed with blue antifreeze. Don't use the red OAT antifreeze on a Triumph (it's meant for modern cars).

The original battery was a hefty beast but not especially high performance, certainly compared to modern ones. You're not likely to have a problem with insufficient CCA if you look for a battery that physically fits. My three all have 063 types but as I said, I don't have a PI saloon any more.

[frenchiemk2]

News from today

I tried to fire up the engine this week. From a fuel can linked to the pump and accumulator line, so that i don't use bottom of the tank fluid.

Did not sart.

Distributor arm was in bad state and i decided to order a new one as i installed the petronix kit.

Today job wad to check fuel lines around the engine bay :

fuel only to cyl6 and a leak to cyl2.

The pressure nanometer says about 3 bars when key switched on contact. But the pressure drops instantly when key is off. I thought it would keep some pressure in the line?

So i pulled out the 6 injectors to see if some dirt (no)and in order to clean them by the time i find the problem.

Maybe the something on the metering unit?

I see a little filter "strainer" on a tr6 parts catalog licated entry of each hose on the metering unit size.

Also the adapters and o rings from injectors to fuel inlets are differents : strange. Does it work because length seems a bit different?

 

[RobPearce]

That could be sticky injectors or a weak pump. My old PI used to be absurdly sensitive to low battery, until I changed the pump. The rapid loss of pressure on key off isn't that surprising, although any stickiness in the pressure regulator will exacerbate it.

[frenchiemk2]

16 minutes ago, RobPearce said:

That could be sticky injectors or a weak pump. My old PI used to be absurdly sensitive to low battery, until I changed the pump. The rapid loss of pressure on key off isn't that surprising, although any stickiness in the pressure regulator will exacerbate it.

Thanks Rob.

Maybe not enough pressure to push through the metering unit + pressure leaks on tank hoses. 

I'll check the pressure ref for a new pump and accumulator thing 🙄 (just ordered 1 for my 100 Quattro Sport... bying new parts again and again)

the more i progress, the more i ask myself how could the car turn before the head was put off... but thing don't get old without damaging and non running isn't goo for cars... 

I want to drive! 😅

[frenchiemk2]

So the pump should deliver 106/110 Lb/sq which is 7.5 bar.

Try to find a Bosch one fitting.

[Nick Jones]

You have a Bosch pump (or a copy) fitted already. Can you see the part number on it? 
 

Generally with Bosch you need to choose a pump as used on one of the K-jet cars in order to get the pressure capability. This usually means a big flow too. Much more than the original Lucas gear pump. This can cause problems with the relief valve and also on the suction side.

The suction side is important as the Bosch pumps don’t suck all that well and are prone to cavitation.  Looks like you have two filters on the suction side and that might well cause problems and be restricting the pumps flow. Normally with Bosch pump installs they have only a coarse strainer on the inlet side, a finer strainer inside the pump itself and the proper, fine filter after their pump.

Nick

Edited September 10, 2022 by Nick Jones

[frenchiemk2]

34 minutes ago, Nick Jones said:

You have a Bosch pump (or a copy) fitted already. Can you see the part number on it? 
 

Generally you need to have a pump as used on one of the K-jet cars in order to get the pressure capability. This usually means a big flow too. Much more than the original Lucas gear pump. This can cause problems with the relief valve and also on the suction side.

The suction side is important as the Bosch pumps don’t suck all that well and are prone to cavitation.  Looks like you have two filters on the suction side and that might well cause problems and be restricting the pumps flow. Normally with Bosch pump installs they have only a coarse strainer on the inlet side, a finer strainer inside the pump itself and the proper, fine filter after their pump.

Nick

thanks, Nick.

I'm not used to Triumphs and Lucas injections, but it seems my Triumph fuel pump system had been modified. But do i have to keep some triumph components or get rid of them to create a VAG like fuel pump system?

What I have on Audis is : 

1 a pre-filter,

2 fuel pump

3 pressure accumulator

4 filter (sometimes close to accumulator, sometimes close to K-Jet

 

 

[Nick Jones]

No it is not standard. Would normally have a Lucas gear pump sucking directly from the big filter mounted on the wheel arch (top left of your pic).  That pumps to the relief valve, which is still present and original, and from there a spill line back to the filter housing (also still present)plus the line forward to the metering unit (which your gauge is connected to). You have to have the relief valve as unlike the K-Jet system, the PI metering unit doesn’t have one built in. There is also another overflow line that comes back from the metering unit to the filter. This is just to carry internal leakage from within the metering unit back.

So, you need:

pre-filter,

pump,

relief valve

high pressure filter.

Accumulator not required.

It is quite common for the Lucas pump to be “upgraded” to a Bosch one. Some kits work better than others but the considerable extra flow can cause problems with the suction filter, the relief valve and also the pipes from pump to relief valve and return line from relief valve to filter housing. The length and type of hose sometimes has to be changed to reduce noise from resonance.

The conversion kits usually keep the original filter housing as it’s really handy as a swirl pot and connection manifold. In my opinion it would be better with a strainer fitted in place of the fine filter element, but mostly it seems to work as it is. You definitely don’t want a second suction filter as you have now.

I have had a couple of Audi 90s and a Golf GTI with K-jet in the past. Ran very well, good economy and not many problems. I think it’s possible to use the same injectors with the PI system.

[frenchiemk2]

10 hours ago, Nick Jones said:

No it is not standard. Would normally have a Lucas gear pump sucking directly from the big filter mounted on the wheel arch (top left of your pic).  That pumps to the relief valve, which is still present and original, and from there a spill line back to the filter housing (also still present)plus the line forward to the metering unit (which your gauge is connected to). You have to have the relief valve as unlike the K-Jet system, the PI metering unit doesn’t have one built in. There is also another overflow line that comes back from the metering unit to the filter. This is just to carry internal leakage from within the metering unit back.

So, you need:

pre-filter,

pump,

relief valve

high pressure filter.

Accumulator not required.

It is quite common for the Lucas pump to be “upgraded” to a Bosch one. Some kits work better than others but the considerable extra flow can cause problems with the suction filter, the relief valve and also the pipes from pump to relief valve and return line from relief valve to filter housing. The length and type of hose sometimes has to be changed to reduce noise from resonance.

The conversion kits usually keep the original filter housing as it’s really handy as a swirl pot and connection manifold. In my opinion it would be better with a strainer fitted in place of the fine filter element, but mostly it seems to work as it is. You definitely don’t want a second suction filter as you have now.

I have had a couple of Audi 90s and a Golf GTI with K-jet in the past. Ran very well, good economy and not many problems. I think it’s possible to use the same injectors with the PI system.

Thanks,

1st i'm gonna clean the injectors (will be a test for that fuelpump in the trunk too)

2nd, i'll take off the second filter before the pump, make sure all hoses are tightened (not sure)

Try as is. 

 

As for Audi injectors we'llsee later because i never drove a Triumph and i badly want it to fire up and have a drive with the car first. Then i'll see if turns great or not. but when i see those injectors ports looking so much to modern racing one, i think about EFi conversion could be great. but that's a 1000-1500 euro bill with ECU injectors and phonic wheel... 

First things first : becoming a runner. 

[Nick Jones]

3 hours ago, frenchiemk2 said:

First things first : becoming a runner. 

Absolutely!

If the pump sounds like it’s full of gravel, that’s most likely cavitation, caused by suction restriction. Too small pipes/fittings, partly blocked filter, fuel level very low, warm/hot fuel are all factors.  You need to have a reliable 105 - 110 psi fuel supply before you can really judge the rest of the PI system.

The PI system is diy rebuildable/ serviceable/tuneable if you are patient and methodical. The parts are available and the information is out there. A few basic special tools are needed, which are also available. Have you found the service notes/cards yet?

I would suggest overhauling the MU with an ethanol friendly seal kit. Also close attention to the throttle linkage is needed. At 46mm each the butterflies are too big really and this makes the balance really critical for idle and low load running.  Wideband O2 sensor really useful for setup and tuning. The MU needs to be tuned to the car, not the test bench!

Plenty of others know more about this. I cheated and converted mine to EFI and coil pack ignition…..

Nick

https://sideways-technologies.co.uk/forums/index.php?/topic/5167-nick-mk2-pi/#comments

[RobPearce]

14 hours ago, Nick Jones said:

I think it’s possible to use the same injectors with the PI system.

I'm not sure. I think the injectors are somewhat different because the injection systems are different - K-Jetronic is a "constant dribble" system where PI is sequential pulsed. Sure, it's the metering unit that does that, but the PI injectors are pintle type so they close fully when not squirting, which I don't think the K-jet ones are.

[Nick Jones]

It’s true they are not identical (and there are a few different styles within the K-jet family with different packaging, flow rates and spray cone angles.

However, AFAIK they are all sprung-pintle type with a 50 psi pop pressure. The way they behave is down to what feeds them; a continuous but variable flow from K-Jet (also sometimes called CIS) or timed pulses from PI.

[frenchiemk2]

Thanks mates!

Well, i took the fuel pump in place to test each injector (i used gas + cleaning fluid, that woirked great on Audi injectors, but not here) :

-2 very good

-1 always closed

- 3 not very nice

I replaced the pump by a new one stored in case of need but could be too weak (6,5 bar and not Bosch, seems to be the limit, maybe Walbro will do more than 6.5 bars) :

- 2 still very good

- 1 not so bad but not perfect

- 3 not good to the point that the pump heated and no flow/squirt

Think i have to buy 4 new injectors (or maybe a try with ultrasonic machine?)

 

 

[Nick Jones]

Some of the original PI injectors can be dismantled for cleaning and servicing. Care needed - small parts and springs!

[frenchiemk2]

17 minutes ago, Nick Jones said:

Some of the original PI injectors can be dismantled for cleaning and servicing. Care needed - small parts and springs!

OK, that's why I saw C.Witor has a rebuilt/renew service for them i presume

[frenchiemk2]

I just realised that i have Bosch injectors... On the right compared to my Audi on the left..

Bosch 0437 502 005

Edited September 11, 2022 by frenchiemk2
ref

[Nick Jones]

Have you found this info already?

http://vitessesteve.co.uk/LucasStuff/Lucas_Petrol_Injection_Manuals

https://fredmillturnparts.com/reference-material-and-downloads/

http://www.lucasinjection.com/MANUALS.htm

Especially the service notes.

[frenchiemk2]

On 11/09/2022 at 22:36, Nick Jones said:

Have you found this info already?

http://vitessesteve.co.uk/LucasStuff/Lucas_Petrol_Injection_Manuals

https://fredmillturnparts.com/reference-material-and-downloads/

http://www.lucasinjection.com/MANUALS.htm

Especially the service notes.

Hi Nick, thanks, i didn't know those refs. thanks

[frenchiemk2]

Today's job :

24h freezer for 4 injectors + thermic shock.

Tested : perfect for 1, nearly good for 2, better but notgood for 1.

Found 2 NOS in USA, may be good next week.

 

Still waiting for a 25D "6" rotor arm, as i purchased a "4" one (stupid of me)...

[Nick Jones]

1 minute ago, frenchiemk2 said:

24h freezer for 4 injectors + thermic shock.

Interesting idea 🙂

[frenchiemk2]

3 minutes ago, Nick Jones said:

Interesting idea 🙂

I put 4 injectors inlet/screw up and outlet down in a little glass jar. 24h freezer.

As i poured 3 liters of boiling water, there where bubbles escaping up through the injectors : meaning the injectors opened enough to let the water flood from bottom to top, as air was released on top. (my interpretation)

[Nick Jones]

Do you have access to a pop-tester as used for diesel (old fashioned diesel now) injectors? They are intended for higher pressures but should still be good for checking that your injectors pop at 50psi.