Ecu code reader (rover gauge)

Ecu code reader (rover gauge)

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Discussion

Dan howes

Original Poster:

8 posts

35 months

Wednesday 9th June 2021
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Evening all....

I’m in need of some advise as I’m fairly new to the world of TVR but happy to be in it!!...I’ve got a 1996 Chimeara 400 which I’ve not owned for long and intend to work on it over the next year or so to bring it up to quite a good standard. I’ve got a problem with the engine as when I fire the car up from cold it starts first time and does what it should do if that makes sense!? ...but after it’s been running for 5-10 mins the revs start to go up and down? Once you get to about 15/20 minutes the car feels like it’s loosing power and miss fires, if I get to a junction and need to stop I have to keep the revs high otherwise it will Rev up and down and cut out...I’m lucky it starts again until it’s cooled down? Unfortunately my temp gauge doesn’t work so can’t see what the temperature is, so I don’t risk going out for longer than 20 mins!...the fans kick in after about 10 mins and then go off again and come back on again. Does anyone have any idea what might be causing this? I’ve been told you can buy a rover gauge?? Will this work on a 1996 Chim?

Any help would be massively appreciated.

Thank you 😊

Belle427

8,947 posts

233 months

Thursday 10th June 2021
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Rovergauge will work, see the classifieds ads for it.
These cars are hard on their ignition components, particularly the plug wires.
If the car still has the original extenders on the plugs I'd start by removing them and putting a decent set of wires on it.
A new set of NGKBPR6ES plugs too.
Do one thing at a time to see if things improve.
Don't go swapping out parts such as the coil and amp willy nilly as quite often the new components can be worse quality than the old ones.
Stepper motors are also a common problem, these can be removed and cleaned easily.

Edited by Belle427 on Thursday 10th June 06:37

Plan B

347 posts

125 months

Thursday 10th June 2021
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It could be the temperature sender that is used by the ECU. Again Roverguage will tell you what the 14CUX ”thinks “ the engine temp is. Remember if this is the root cause there are two temperature sensors on the engine - I think the other feeds the gauge on the dash.

Classic Chim

12,424 posts

149 months

Thursday 10th June 2021
quotequote all
There are 3 temp sensors fitted to the inlet manifold.
1 Tvr temp sender to gauge positioned at the front of manifold.
2 Sensor positioned at the top of inlet manifold on n/s bank used by ECU.
3 redundant sensor ( smaller and directly behind the bigger ecu sensor) in manifold. Forget that one.
The ecu sender can fail and cause erratic idle or poor running.
If it runs ok cold also look at ignition components that often breakdown when hot, coil / amp are often the cause once warm.
RG will help detect a few of these faults.

Steve_D

13,746 posts

258 months

Thursday 10th June 2021
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There are in fact 4 temp senders.
1. For the gauge is low down on the centre front of the inlet manifold. It is almost out of sight behind the dizzy.
2. For the ECU at the top front of the inlet. It is a 2 pin sensor and has a brown connector.
3. An unused sender just behind the ECU sender . Look for threads on here recommending a new sender to be fitted here for the gauge instead of the one at 1.
4. For the fuel rail temperature. Mounted on the fuel rail O/S front.

When you get RoverGauge you will be able to see both coolant and fuel temps. So when you first switch on they should both read about the same and give an indication they are both working. No gaurantee they will stay working as they warm up but a good starting point.

Don't be shy of asking questions. Plenty of people on here happy to help.

Steve


Edited by Steve_D on Friday 11th June 08:38

Dan howes

Original Poster:

8 posts

35 months

Thursday 10th June 2021
quotequote all
Thank you all for your much valued imput in regards to the above issues I’ve been having! It’s so nice to have this amazing support at the touch of a bottom!

Dan

s p a c e m a n

10,777 posts

148 months

Friday 11th June 2021
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Think it's the Griff boys who touch bottoms, we're all a bit more manly in here hehe

Belle427

8,947 posts

233 months

Saturday 12th June 2021
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laugh

s p a c e m a n

10,777 posts

148 months

Saturday 12th June 2021
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Seeing as this is the most recent thread I might as well hijack it for a bit of help. I spent last night trying to track down what I thought was a spark issue when all of a sudden I had these error codes flash up for a few minutes. I'd had some rough running, dodgy idle and a couple of cut outs where it didn't want to start again and a decent fuel smell which is why I was tracing heat related spark stuff.

What is the ECU actually monitoring for injector faults? Is registering a fault in the loom or does it know the injector isn't firing from the lambda sensor, or both/something else?

Cheers beer


Dan howes

Original Poster:

8 posts

35 months

Saturday 12th June 2021
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Sorry meant to say button!!! Lol

blitzracing

6,387 posts

220 months

Monday 14th June 2021
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The ECU will try and keep the lambda probes switching by altering the amount of fuel going in. Basically a lean mixture below 14.7:1 the probe output is 0 volts and a rich mixture above 14.7:1 is 1 volt or more, so the ECU constantly cycles the probes between 0 and about 1.4 volts if all is well. If the probe stops switching the ECU will keep adding more and more fuel to try to get the probe voltage to lift. if it runs out of range and the voltage is still at zero it flags a lambda probe fault after several minutes of running. It cant tell the difference between a 0 volt probe and an air leak or injector fault that might make it lean on one bank, hence the injector error as well. Easiest thing to do is swap the probes over and see if the fault moves banks.

Edited by blitzracing on Monday 14th June 18:53

s p a c e m a n

10,777 posts

148 months

Monday 14th June 2021
quotequote all
Magic, thanks for the help. I checked all of the loom, connectors and looked for air leaks yesterday and found nothing obvious. The car was behaving itself for the short run after that but I'll take a better look at lambda side of things and swap them over to see if the error changes for next time.

Steve_D

13,746 posts

258 months

Tuesday 15th June 2021
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s p a c e m a n said:
.............. I checked all of the loom, connectors .................
You may not be aware that the engine loom is Rover rather than TVR. In the Rover the lambdas are at the back of the engine so TVR had to extend the leads. On both sides of the engine you will find another lambda connector hiding amongst the injector wiring.

Steve

Penelope Stopit

11,209 posts

109 months

Tuesday 15th June 2021
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s p a c e m a n said:
I checked all of the loom, connectors and looked for air leaks yesterday and found nothing obvious
Disconnecting and removing the ECU as a security measure might cause problems

Seem to recall it was thee that does this

How many disconnects and connects are you up to?

Has a female ECU Plug terminal opened up a little?

Just a thought