Fuel trims all over the place!

[LPGC]

Handy to have one of those temp sensors and cheap enough! If the temp range went higher I'd order one myself for monitoring auto box temp when towing with a fabled A604 equipped Grand Voyager...

Probably not a good idea to T into the main rad pipe, dunno what that will do to engine running temp, engine warm-up time or flow through the heater circuit..

Simon

[Gilbertd]

Probably not a good idea to T into the main rad pipe, dunno what that will do to engine running temp, engine warm-up time or flow through the heater circuit.

It would certainly screw up the change over time as the main rad hose won't have any flow through it until the stat opens.

[57jam89]

Probably not a good idea to T into the main rad pipe, dunno what that will do to engine running temp, engine warm-up time or flow through the heater circuit.

It would certainly screw up the change over time as the main rad hose won't have any flow through it until the stat opens.

It wouldn't make any difference as the fed to the heater comes off the same main rad hose. The reduser at the monent is plumbed parallel to heater so I was thinking of the reducer having it's circuit so it wouldn't be affected by the heater valves closing. If that's what the problem is.

[LPGC]

Probably not a good idea to T into the main rad pipe, dunno what that will do to engine running temp, engine warm-up time or flow through the heater circuit.

It would certainly screw up the change over time as the main rad hose won't have any flow through it until the stat opens.

Agreed, Richard. I thought of that too, though stat is on outlet side before rad while my understanding of his idea was that he'd be using the outlet side of heater piping to flow into inlet side of rad. The effect would still be as we both said (slowing warmup / changeover time / etc). Would be complicated to explain all the various ways rad plumbing could be involved but they'll all have negative implications....

Edit due to 57Jam89 (also Simon) and my post crossing: Simon, the diagram shows the return from heater and main rad are joined, not the feed, this is a lot more like we'd expect (than feeds joined) and as I implied above. Wouldn't expect you to T in series to the main rad feed or in parallel with the rad as it'd be obvious the reducer wouldn't get warm until stat opened and then it's temp could fluctuate wildly.

Another thing I spotted, not that I think it makes any difference (and diagram is as I remember V6 plumbing) but diagram says V6 for the engine and then says 'diagram for V8 engine' at bottom of page!

Simon

[57jam89]

Probably not a good idea to T into the main rad pipe, dunno what that will do to engine running temp, engine warm-up time or flow through the heater circuit.

It would certainly screw up the change over time as the main rad hose won't have any flow through it until the stat opens.

Agreed, Richard. I thought of that too, though stat is on outlet side before rad while my understanding of his idea was that he'd be using the outlet side of heater piping to flow into inlet side of rad. The effect would still be as we both said (slowing warmup / changeover time / etc). Would be complicated to explain all the various ways rad plumbing could be involved but they'll all have negative implications....

Edit due to 57Jam89 (also Simon) and my post crossing: Simon, the diagram shows the return from heater and main rad are joined, not the feed, this is a lot more like we'd expect (than feeds joined) and as I implied above. Wouldn't expect you to T in series to the main rad feed or in parallel with the rad as it'd be obvious the reducer wouldn't get warm until stat opened and then it's temp could fluctuate wildly.

Another thing I spotted, not that I think it makes any difference (and diagram is as I remember V6 plumbing) but diagram says V6 for the engine and then says 'diagram for V8 engine' at bottom of page!

Simon

Hi Simon,
The picture for the v8 engine was below 'diagram for v8 engine'.

The return from heater doesn't joint rad pipe but connects to inlet side of water pump and header tank.

Thanks.

[57jam89]

Update-
Well the jags been running great, nice and smooth with no misfires, thanks Simon!

I fitted the temperature gauge temporary on top of my dash with the temperature prode cable tied to the reducer. In traffic and speeds up to 50mph it's 63-67c, 70 mph with cruise control about 55c and 90mph 49c.
It doesn't make any difference if heater is set to cold or hot or if a.c is on or off.

Also had the dash on engineers mode so I could read the coolant temp and it was always at 92-95c.

Are these normal temp reading for a reducer?

Thanks.

[Gilbertd]

A bit low, normally you'd expect them to be the same as the coolant temp but as you've had to plumb in parallel, then you're never going to achieve full flow. Not low enough to cause a problem though.

[LPGC]

Pleased to read that mate, and thanks for the thumbs up.

Pretty much agreed with the gist of Gilbert's comment, mostly telling on that 90mph+ reading though, wouldn't be concerned at 67c if it stayed at that. Falling to 49c at 90mph might indicate slightly poor flow - was the 90mph reading taken cruising at 90 or having booted it up to 90 a few times?

Simon

[57jam89]

Pleased to read that mate, and thanks for the thumbs up.

Pretty much agreed with the gist of Gilbert's comment, mostly telling on that 90mph+ reading though, wouldn't be concerned at 67c if it stayed at that. Falling to 49c at 90mph might indicate slightly poor flow - was the 90mph reading taken cruising at 90 or having booted it up to 90 a few times?

Simon

It was cruising. Thanks.

[LPGC]

Low temp at a constant cruise could be worse than low temp after repeated booting - even cruising at 90 the engine won't be using nearly full power like when booted.

Just converted the V12 twin turbo AMG jobby, now starting on another AMG, 2007 6.3 V8 ML. The ML has a pump to help circulate coolant through the heater circuit, it's a neat little unit, probably only 2x2x2". Got me thinking these pumps might be handy in situations like yours or where coolant flow through reducer might be a bit low. Probably just a few quid from a scrapyard, looks like 19mm fittings, outlet is at 90deg to inlet, simple electricals are earth and +12v. Just spent an hour looking at the plumbing etc on the ML, had it running with climate at full cold AC on, then climate at full hot, then with climate system completely off - Whenever ignition is on this pump runs and water is circulated through the heater matrix, pipes stay very hot, so I reckon I'll plumb reducer in series with the matrix on this model.

Simon

[57jam89]

Low temp at a constant cruise could be worse than low temp after repeated booting - even cruising at 90 the engine won't be using nearly full power like when booted.

Just converted the V12 twin turbo AMG jobby, now starting on another AMG, 2007 6.3 V8 ML. The ML has a pump to help circulate coolant through the heater circuit, it's a neat little unit, probably only 2x2x2". Got me thinking these pumps might be handy in situations like yours or where coolant flow through reducer might be a bit low. Probably just a few quid from a scrapyard, looks like 19mm fittings, outlet is at 90deg to inlet, simple electricals are earth and +12v. Just spent an hour looking at the plumbing etc on the ML, had it running with climate at full cold AC on, then climate at full hot, then with climate system completely off - Whenever ignition is on this pump runs and water is circulated through the heater matrix, pipes stay very hot, so I reckon I'll plumb reducer in series with the matrix on this model.

Simon

Interesting to know! I always thought all but basic cars had heater valves to make the a.c side of heater more effective (because of no heat passing through). And more interesting is mercedes engineers need to fit a pump to help the flow through heater.
The v8 s type has a small coolant pump but still has a heater valves.

Today I had 2 short 90 mph runs which were one after the other, 15mins from cold start and 11c outside and both times the reducer dropped to 45c!
Should I worry about this?

Thanks.

[LPGC]

Many cars with AC don't have a heater water flow shut-off valve, would say most don't. Where the heater system uses variable water flow control valves as a means to adjust heater output temp, your Jag included, water flow valve full heater cold position may cut off water flow entirely anyway.

I think Merc engineers fitted the pump to improve flow but other advantages are that the heater can work for a while without the engine running and the pump helps bleed the heater circuit.

Depending on thermostat / vehicle manufacturer design, coolant temp may be as low as 75c or as high as 100c during a cruise. Highest coolant temp is usually seen at idle just before the radiator fan kicks in at around 100c on vehicles without a thermo-viscous fan. If coolant temp is say high 80s during a cruise then reducer could be expected to be in mid 70's high 60's during a cruise... Still the 45c is low.


Simon

[Brian_H]

Low temp at a constant cruise could be worse than low temp after repeated booting - even cruising at 90 the engine won't be using nearly full power like when booted.

Just converted the V12 twin turbo AMG jobby, now starting on another AMG, 2007 6.3 V8 ML. The ML has a pump to help circulate coolant through the heater circuit, it's a neat little unit, probably only 2x2x2". Got me thinking these pumps might be handy in situations like yours or where coolant flow through reducer might be a bit low. Probably just a few quid from a scrapyard, looks like 19mm fittings, outlet is at 90deg to inlet, simple electricals are earth and +12v. Just spent an hour looking at the plumbing etc on the ML, had it running with climate at full cold AC on, then climate at full hot, then with climate system completely off - Whenever ignition is on this pump runs and water is circulated through the heater matrix, pipes stay very hot, so I reckon I'll plumb reducer in series with the matrix on this model.

Simon

Interesting to know! I always thought all but basic cars had heater valves to make the a.c side of heater more effective (because of no heat passing through). And more interesting is mercedes engineers need to fit a pump to help the flow through heater.
The v8 s type has a small coolant pump but still has a heater valves.

Today I had 2 short 90 mph runs which were one after the other, 15mins from cold start and 11c outside and both times the reducer dropped to 45c!
Should I worry about this?

Thanks.

Given your cable tying your probe to the outside of the vapouriser the reading might not be accurate, particularly at speed. It might be worth seeing if you can insulate the probe from the air if your still doing this to get a slightly better reading (the outside of the vapouriser will be cooler than the inside due to the passing air as well). Might be worth monitoring the temperature in this setup with your temp sensor and comparing at the same time to the one shown in the lpg software itself (assuming its got a sensor mounted in/near to the vapouriser that is, and not using the cars own temp sensor or similar).

[LPGC]

Good points, Bri.

[57jam89]

Update-
Well a wrapped some pipe lagging around the vapouriser and it didn't made any different to the temp readings.
I'm not going to worry about it as it's running spot on (thanks Simon).

[LPGC]

You're welcome.

All good then. Have you tested what happens when heater is on full at low speeds etc, just to make sure all is OK? I suppose the proof will be if all continues to be OK in the winter...

On holiday atm in Cornwall - apologies for late/short replies while I'm away.

Simon

[57jam89]

You're welcome.

All good then. Have you tested what happens when heater is on full at low speeds etc, just to make sure all is OK? I suppose the proof will be if all continues to be OK in the winter...

On holiday atm in Cornwall - apologies for late/short replies while I'm away.

Simon

Hi, makes no difference if heater is on full cold or full heat.

It's very nice in Cornwall! Enjoy your holiday!

Thanks.

[57jam89]

Hi all,
Just started to have problems with the lpg turning itself off. I switch it back on and sometimes it ok for 20 mins or 2 mins.

Checked with laptop and have these faults logged -
Pressure sensor not connected
gas temperature sensor not connected
Vacuum sensor not connected.

It has a Europegas ABS400KPA MAP Pressure Sensor New type 4-pin LPG Autogas Pressure and Vacuum Sensor for Europegas autogas systems.

The ecu with sensors were new about a year ago so can't see it been faulty all ready.

[LPGC]

All pointing to a dodgy pressure sensor though. When you fitted it did you make sure the plug seal was OK and it's not fitted in a place where water ingress or heat could cause problems? Same goes for the ECU. Also worth checking main live and earth connections.

Simon

[57jam89]

All pointing to a dodgy pressure sensor though. When you fitted it did you make sure the plug seal was OK and it's not fitted in a place where water ingress or heat could cause problems? Same goes for the ECU. Also worth checking main live and earth connections.

Simon

Hi Simon,
Yes the seal is good but it is fitted beside the inlet manifold which is above the driver's side exhaust manifold so maybe a heat problem. Come to think about it the problem only starts after about 30 mins of driving.

I did check power and earth both ok.

Thanks.