Jump to content

Tr6 efi


Recommended Posts

Tr6 efi is now running well most days, till we got to this hot spell. On a run round country lanes she is fine till you in to traffic, temp gauge starts to rise electric fan come on and just about copes for short periods, but never boils as such. Took a reading with laser temp gauge and it’s about normal around 80c. It’s the air temp that gets very hot 40c + when this happens the tickover starts to suffer, starts around 900 and slowly goes down to 500 then stalls o2 gauge goes very week 16 to 18.

Have changed the rad new lower stat flushed the engine out , slightly better, one thing I have got is very very high oil pressure, cold 95 tickover hot 65 

2000rpm hot over 100

Any ideas welcome 

Phil

 

Link to comment
Share on other sites

Not sure what problem we are advising on here?

Oil pressure - the numbers you quote are way high for idle. I suspect your gauge lies as 95 psi cold idle plus some revs would likely produce oil filter popping pressures. Otherwise there is something amiss with the relief valve.

Hot idle problem - I'm almost sure this will prove to be a heat-soak problem with your inlet air temperature sensor. The signal from this is used as part of the ECUs fuelling calculation to correct for air density. Warm air is less dense so less fuel required but if the sensor is being over-warmed it will over-correct and cause a lean mixture. Where is the sensor located?

Nick

Link to comment
Share on other sites

I see a sensor locating problem, too but rising to 18AFR

is a bit high for the reason of bad location. A difference

of lets say 40 degrees air temp  just from my feeling will

not be enough to cause such problems.

 

My air temp is taken in the original PI system just after the air filter

besides radiator and before the air tube to collector.

 

The other problems with oil pressure and water temp

are not EFI related and should be solved before going on.

 

Did not read the whole thread why is there no AFR targeting

and EGO control employed?

Link to comment
Share on other sites

Basically the engine is getting extremely hot although the water temperature is not getting abnormally high, the ecu struggles to maintain an even tickover around 850rpm dipping to 500rpm. Engine is getting very tight and runs unevenly at normal speeds (40-60).

Air sensor is located level with the radiator below halfway

Link to comment
Share on other sites

What is your basis for saying that the engine is getting extremely hot if the water temperature is not showing it? Or the basis for saying the engine is getting tight? 

If it's going very lean then it will not run well, lacking power and tending to "hitch", which could certainly give the impression that the engine is getting tight.  Quick and dirty test is to switch off and spin it on the starter.  If it spins normally, no worries.  If the starter struggles, uh oh......  What ECU are you running?  Are you able to connect to it and read live parameters?  Would be very interesting to read inlet air temperature.

If the engine really is getting physically tight then you need to investigate the oil pressure issue ASAP, though assuming the pressure measurement point is in the usual spot (oil gallery hole just below distributor drive) you are measuring main gallery pressure, which would appear very healthy, though very suspicious of your gauge accuracy as mentioned earlier.

Nick

Link to comment
Share on other sites

Hi Nick , glad to hear you're feeling better.

The idea of using the starter was suggested this morning, will try later.

I'm running a Canems unit , air temp is quite high at 40c .

In the process of acquiring another gauge to check.

Link to comment
Share on other sites

That plug often has a tap in it, and is the lowest point of the water jacket, so that the block may be drained of coolant, impossible any other way.     But this means that any crud falls into the pit behind the tap and is not washed away, so that it bungs up.    It doesn't mean that 5 and 6 bores have no cooling flow.

But it's not just crud from use.    When I rebuild an engine, I always take out the plug or tap and probe from above and below into the pit, and I've often found sand.  The only sand that was ever there was when the block was cast, so this is residual from then, poorly cleaned out in the foundry.    Casting sand is bound together by a binding agent, which could be an oil, but I've no idea if that was the case when these blocks were cast.   Could that be what you found behind the plug?

John

Link to comment
Share on other sites

7 hours ago, Noswal said:

Removed the water jacket plug near the starter , completely blocked , not rust but thick oil crud . So no water getting to 5 and 6 cylinders, but where did the oil come from?

Blockage here is common.  It's a "far corner" of the cooling system with low flow velocities, so "stuff" accumulates there.  The blocks from the saloon range are even worse as the engine is canted to that corner.  In fact, unless the debris is really deep I don't think it has that much effect on engine cooling - though as an indication of general cooling system condition it's interesting.

Is it really oily sludge in there or could it be the black form of iron oxide, wet with water and elderly antifreeze?  To get oil in the water jacket is pretty rare on these engines (water in oil less so).  Only vaguely likely route in, other than when the engine is apart for major works, is from the oil-way in the back left corner which feeds the rocker gear, though oil leaks at the head gasket there tend to be external rather than to water-ways.

As an aside while preparing the block for my PI engine rebuild, I was at first convinced the block drain had never been through drilled.  It was SOLID.  After some close examination with a bright light through the waterways in the head face I could see that the water jacket appeared to get shallower towards the back right corner.  I then started beating at the apparent floor of the water jacket with a long sharp, screwdriver and hammer and chunks started to come out.  Deposits in the corner by the drain were 30mm+ deep and extremely hard, like concrete.  Took ages to get it all out.  Possibly some was original casting sand, possibly it was all fossilised rust and lime.

Nick

Link to comment
Share on other sites

Was completely blocked up to the far side still no water came out , have some welding wire which I pushed to the right and left up the passages eventually got it cleared of debris continued flushing the block out till the water ran clear.

It's all back together and running temperature more consistent now throughout the block using the laser temperature gauge where before there was 25c difference. Let's hope that's cured it only time will tell.

Thanks for the help

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...