Running rough and lacking power

**PhilipA** · 18th February 2015, 09:00 PM

As a long shot I plugged in the Bluetooth OBD11 and turned on the Torque Pro App. And it shows "open loop due to insufficient temperature". After driving for an hour in 35+?C there was ample time to get up to temperature!

* I have checked the temperature sensor output and the voltage varies with the engine warming up to eventually sit at around 1v at operating temp (as per RAVE).

I went right back to your first post, and I still think it is temperature sensor related.
Really seeing all the things you have done, why not try a new temperature sensor.
In the 14CUX there are two temperature sensors, one for the gauge and one for the ECU. I don't know whether the GEMS is the same but the one to change is the ECU sensor which will have an injector plug on it. Note sometimes people mix up injector no 2 plug with the sensor plug. The usual way to check is by reading the resistance across the sensor terminals , which should be 300 Ohms at 82+. I don't think sensors have changed much even up till now.

The fuel temperature sensor is only a trim sensor in 14CUX and I think in GEMS. It has on effect on mixture of +- 10% so is probably not a cause of your problems.

Finally have you done a compression test? These engines are notorious for sticking exhaust valves if not driven hard , Another poster suggested a vacuum test which would also indicate a stuck valve.

If the engine goes into closed loop the plugs will be dead white, as I found when I added O2 sensors to my 14CUX.
But I would check the temperature sensor again.

PS I just looked at RAVE and I think you have been looking at the Thor page which gives voltages. The Section 19 page 22 which refers to GEMS says the resistance should be 300 Ohms ! as I have said. It is page 357 of 1361 in the PDF.
Regards Philip A

**mtb_gary** · 19th February 2015, 09:50 AM

Thanks Philip

I haven't done the compression or vacuum test as yet but a sticking exhaust valve could make sense. The open loop is correct for the 1996 model as there are no O2 sensors. As for the ECU sensor, I'll see what values are being provided to the ECU.
I'll be in Melbourne for a bit over a week starting tomorrow so it may be a project for when I return home.

Gary

**mtb_gary** · 19th February 2015, 10:14 AM

I've just done the "paper test" on the exhaust. Not good news

, the paper gets sucked in. PhilipA, it looks like your prognosis of the stuck exhaust valve may be correct. I will verify with the compression guage shortly.

Gary

**blindin** · 2nd March 2015, 08:59 AM

Hi Gary.
I would try 2 types of tests on it first to see if you can figure it out any better.
The first is a normal compression test.
Second is a another pressure check. You set the piston to tdc, and then plug the compressor in via a pressure guage and regulator. This will tell you how Babylon worn the rings / valves are.
If it is just a sticking valve the second test should appear fine.
You could then try a heap of fuel additive / lubricant, and a good thrash up the road to try and clear and carbon and crap. Even try ultimate fuel as that may even help.
Good luck, hope it isn't to bad

**mtb_gary** · 5th March 2015, 09:58 PM

Just as an update. I ran a compression test on the car tonight

Cylinders 2,4,6,8,5 and 7 all sitting around 135-140 Psi

Bad news cylinders 1 and 3 around 20 psi

After running the cleaners and higher octane fuel the plugs have certainly cleaned up and are a light colour now. all excep for 1 and 3 of course. I'm still hoping that the cleaners and higher octane petrol will unstick the valves (if in fact that is the problem). Oil is still free of coolant and the coolant is not being discouloured.

Gary

**blindin** · 5th March 2015, 10:30 PM

Have you pulled the rocker covers and checked what's happening?

**PhilipA** · 6th March 2015, 05:44 AM

AFAIK cleaners will not fix a stuck valve.
But to me the most likely problem is a blown head gasket between 1and 3.

Regards Philip A

**mtb_gary** · 6th March 2015, 08:48 AM

Originally Posted by blindin

Have you pulled the rocker covers and checked what's happening?

Not yet Simon. That could be a job for today

Gary

**mtb_gary** · 6th March 2015, 08:50 AM

Originally Posted by PhilipA

AFAIK cleaners will not fix a stuck valve.
But to me the most likely problem is a blown head gasket between 1and 3.

Regards Philip A

Phillip, I tend to agree. I was thinking about ordering a gasket kit and head bolts in readiness.

Gary

**mtb_gary** · 6th March 2015, 05:00 PM

I've just been doing some ringing around for prices

If I go down the genuine LR parts for the Headset gasket & seals (no bolts) P/N STC4082 I'm up for over $900 before buying the new bolts............Needless to say I'm heading down the non genuine path at that price! Has anyone used any of the aftermarket kits and found a good one? The prices vary quite dramatically. I would prefer to be purchasing from a local supplier if possible.

Gary

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