1998 Chimaera 450 Misfire after minor job

[SteveSNZ]

I'm ready to give up now. I have a quote for about $5K NZ to change the ECU out to a Link. Pity really as the car has only done 22K Km and I wanted to keep it original. But now its just bonkers and I have no local support. Link computer or set fire to it hmmmmm.

[Classic Chim]

I’d be inclined to re check TDC and identify which valves are opening and when then check rotor position.

[Classic Chim]

In defence of a good modern Ecu install which includes crank trigger wheel and if your lucky a really good new loom and sensors then a competent mapper you’d end up with a car transformed and all this uncertainty of reliable parts etc largely removed allowing extensive use of the car knowing its running and fuelling is being optimised with more power/ economy and reliability which is a step change on how you can utilise the car with much more confidence.
But that’s not going to fix it right now.
Surely someone has a Landy with working parts somewhere near you. do some basic checks again for your sanity then try some known working parts on the car.

I’d just go back to the start first and check timing and work on from there.

[Belle427]

I feel your pain and i hope you nail it eventually.
I will say though going aftermarket may be one of the best mods you could ever do to the car, there isnt much wrong with the 14 cux when its running well but good spares are few and far between, same goes for the ignition system.
Haltech are a respected company that ive seen the mighty car mods guys on you tube using a lot, may be worth a look.
You can diy it if your fairly hands on too to save some money, its not too bad if your confident with wiring, my Megasquirt conversion cost me around £600 in total but i did claw back some money with the old Ecu etc.

[SteveSNZ]

Classic Chim said:

I’d be inclined to re check TDC and identify which valves are opening and when then check rotor position.

Essentially that why I tried moving the plugs around, but I have done this before and ultimately the timing was looking good when I had the car running. The problem is that its deteriorated so that I can't now run it to check timing again. Would you agree that moving the leads to the opposite posts would be the same as having the disty 180deg out? If yes, then I'm comfortable that the piston is at TDC and Ive tried the only 2 possible rotor positions that alight to the No1 lead.

[SteveSNZ]

Belle427 said:

I feel your pain and i hope you nail it eventually.
I will say though going aftermarket may be one of the best mods you could ever do to the car, there isnt much wrong with the 14 cux when its running well but good spares are few and far between, same goes for the ignition system.
Haltech are a respected company that ive seen the mighty car mods guys on you tube using a lot, may be worth a look.
You can diy it if your fairly hands on too to save some money, its not too bad if your confident with wiring, my Megasquirt conversion cost me around £600 in total but i did claw back some money with the old Ecu etc.

Yes I'm definitely at the end of my time with the 14CUX. This is my 2nd Chimaera and my last car was also off the road for 6 months whilst working through issues with Ian Whalley. That turned out to be faulty soldering on his aftermarket AFM. Awesome guy though, he really took ownership of the problem.

[SteveSNZ]

Belle427 said:

I feel your pain and i hope you nail it eventually.
I will say though going aftermarket may be one of the best mods you could ever do to the car, there isnt much wrong with the 14 cux when its running well but good spares are few and far between, same goes for the ignition system.
Haltech are a respected company that ive seen the mighty car mods guys on you tube using a lot, may be worth a look.
You can diy it if your fairly hands on too to save some money, its not too bad if your confident with wiring, my Megasquirt conversion cost me around £600 in total but i did claw back some money with the old Ecu etc.

That sounds like a better number than NZ$5K . I don't want to spend more than I need to but also don't want to end up with a car that's modified and cant be looked after by someone local. I think there are another couple of TVR owners here (NZ) that have changed their ECU's. Once I calm the farm a bit I'll give this some more thought.

[QBee]

SteveSNZ said:

Belle427 said:

I feel your pain and i hope you nail it eventually.
I will say though going aftermarket may be one of the best mods you could ever do to the car, there isnt much wrong with the 14 cux when its running well but good spares are few and far between, same goes for the ignition system.
Haltech are a respected company that ive seen the mighty car mods guys on you tube using a lot, may be worth a look.
You can diy it if your fairly hands on too to save some money, its not too bad if your confident with wiring, my Megasquirt conversion cost me around £600 in total but i did claw back some money with the old Ecu etc.

That sounds like a better number than NZ$5K . I don't want to spend more than I need to but also don't want to end up with a car that's modified and cant be looked after by someone local. I think there are another couple of TVR owners here (NZ) that have changed their ECU's. Once I calm the farm a bit I'll give this some more thought.

Just think carefully and go with whatever aftermarket ECU solution will work with the RV8 and is supported and mapped locally.

I went for an Emerald K6 set up here in the UK because it was supplied, installed and mapped by Jools (Spitfire4V8), who works 40 miles from me, and the manufacturer is only about 100 miles away. My TVR expert also understands this system.

You are 12000 miles from the UK, so your system needs to be maintained and mapped by someone locally to you, ideally with other mappers around in NZ in case your number one choice gives up, retires, dies or whatever. Unless you are looking for something more than standard engine management, then the system is less important than the ability to get problems solved and it mapped in the first place.

[SteveSNZ]

Yes another update. Still no success but some interesting results.
1st a dropbox link to some videos and files
https://www.dropbox.com/scl/fo/z3a7w8xgaxkhm6wjl91...

I purchased yet another MAF - advertised as 2 years old and tested = No Change with starting and also I've not measured voltages yet (ran out of steam).

I watched a couple of Videos on YouTube and came up with a plan to definitively test the ignition and timing.
Remove all plugs and ignition leads
Remove rocker covers to confirm valve positions and TDC at firing stroke = Done
Roll back engine 45 degrees then forward again to 6 deg BTDC = Done
Check and mark Rotor Arm position = No Change required
Connect King lead
Connect No1 lead to a spark plug and lay spark plug on engine (earth)
Loosen distributor clamp
Ignition on
Rotate distributor clockwise and anticlockwise so that the No1 lead passes the rotor arm several times

Outcome
Visible Strong Spark for each pass of the lead to Rotor arm
All Injectors can be heard clicking (firing) - I believe both banks fire when cold
Fuel pump runs for a short time for each spark

Conclusion
Ignition is good in all regards
ECU is working
Injectors are firing
Fuel pump runs as expected

Unknown
Is fuel pressure good
Are injectors delivering fuel

Annoying - Car wont start

I Purchase a cheap Fuel pressure gauge = Showing low fuel pressure (about 28PSI)
Next - Regret buying a cheap unit - Will try to test the gauge using an air pump with gauge and some kind of joiner.
Check the newly purchased AFM Voltage readings

[SteveSNZ]

Worth mentioning that to remove the rocker cover I removed the plenum etc. This gave me a good chance to inspect wiring and the earth straps at the back of the engine. All looks fine to me.

[SteveSNZ]

Classic Chim said:

I’d be inclined to re check TDC and identify which valves are opening and when then check rotor position.

Your right of course. Please see my latest update where I did this and added in some good ignition tests. I really think the method I used to test the ignition is very helpful as it took about 2 hours from the beginning to end and definitively answers any questions about the ECU to ignition, fuel pump and injector functions.

[Belle427]

Normally on one of the lower timing cover bolts there are some important ground cables i believe are related to the Ecu, from memory the large ground to outrigger goes here too?
Were they present on yours?

[blitzracing]

Oh boy. I hate faults you cant follow through logically and this is all over the place. Can we take several steps backwards so I know where I am?

As of today do you still get error codes from RoverGauge for AFM and throttle pot mismatch?

Try running RoverGauge with the ignition on but the engine not running. Then just blip the starter but not enough to start. This should cause RoverGauge to do a reading of the AFM voltage with no air flow- this should be 6%

What is the idle AFM reading if it will run?

What is the CO trim voltage?

So far everything I see points at the AFM or wiring as this is the biggest factor controlling the amount of fuel.

Measuring fuel pressure if fraught with danger as the inlet vacuum controls the pressure on a running engine so its is lower than the 3 bar quoted. The only way to test it is to turn the fuel pump on with RoverGauge with just the ignition on and check its 3 bar.

If your plugs are still sooting up badly its nothing to do with a misfire as the car does not have lambda feedback that causes mis fuelling if the mixture does not burn correctly due to ignition.

Just generally with diagnosis its really important you double check your results, as one small error early on can take you up completely the wrong path so you may swap bits and add another fault in the process..

[SteveSNZ]

Belle427 said:

Normally on one of the lower timing cover bolts there are some important ground cables i believe are related to the Ecu, from memory the large ground to outrigger goes here too?
Were they present on yours?

There are no earth cables connected to the rocker cover on my car. There is a group of earths that are bolted to the block, pretty much at Piston no 7. I’ve also tested all the earths that go directly to the ecu and all test good.

The one earth I’m not certain about is the one that connects the sensors together. I don’t know if that should be connected to earth or if it’s earthed via the ECU. I’ve tried jumperiing it to earth but it makes no difference.

Also, I didn’t go anywhere near the rear of the car when I changed the timing cover gasket which is when this problem started. It is possible that when jacking the car up I’ve damaged a cable. I’ll be checking all the cables to the fuel pump this weekend.

[SteveSNZ]

blitzracing said:

Oh boy. I hate faults you cant follow through logically and this is all over the place. Can we take several steps backwards so I know where I am?

As of today do you still get error codes from RoverGauge for AFM and throttle pot mismatch?

Try running RoverGauge with the ignition on but the engine not running. Then just blip the starter but not enough to start. This should cause RoverGauge to do a reading of the AFM voltage with no air flow- this should be 6%

What is the idle AFM reading if it will run?

What is the CO trim voltage?

So far everything I see points at the AFM or wiring as this is the biggest factor controlling the amount of fuel.

Measuring fuel pressure if fraught with danger as the inlet vacuum controls the pressure on a running engine so its is lower than the 3 bar quoted. The only way to test it is to turn the fuel pump on with RoverGauge with just the ignition on and check its 3 bar.

If your plugs are still sooting up badly its nothing to do with a misfire as the car does not have lambda feedback that causes mis fuelling if the mixture does not burn correctly due to ignition.

Just generally with diagnosis its really important you double check your results, as one small error early on can take you up completely the wrong path so you may swap bits and add another fault in the process..

Hi Mark, thanks for checking in. I'll run through all the AFM voltage and wire tests again. At this stage I'm not getting any fault codes generated and the plugs aren't sooting up or particularly wet. its morning now here in NZ so I'll report back ASAP.
Cheers

[Belle427]

SteveSNZ said:

Belle427 said:

Normally on one of the lower timing cover bolts there are some important ground cables i believe are related to the Ecu, from memory the large ground to outrigger goes here too?
Were they present on yours?

There are no earth cables connected to the rocker cover on my car. There is a group of earths that are bolted to the block, pretty much at Piston no 7. I’ve also tested all the earths that go directly to the ecu and all test good.

The one earth I’m not certain about is the one that connects the sensors together. I don’t know if that should be connected to earth or if it’s earthed via the ECU. I’ve tried jumperiing it to earth but it makes no difference.

Also, I didn’t go anywhere near the rear of the car when I changed the timing cover gasket which is when this problem started. It is possible that when jacking the car up I’ve damaged a cable. I’ll be checking all the cables to the fuel pump this weekend.

Not the rocker cover, the timing cover usually has grounds fitted to a bolt near the oil pressure sender.
Just thought as you had removed it to do the gasket it was worth mentioning.

[SteveSNZ]

Belle427 said:

Not the rocker cover, the timing cover usually has grounds fitted to a bolt near the oil pressure sender.
Just thought as you had removed it to do the gasket it was worth mentioning.

I completely misread that . Yes there is an earth point on the front timing case and the wires that connect to it have all been checked.

[SteveSNZ]

blitzracing said:

Oh boy. I hate faults you cant follow through logically and this is all over the place. Can we take several steps backwards so I know where I am?

As of today do you still get error codes from RoverGauge for AFM and throttle pot mismatch?

Try running RoverGauge with the ignition on but the engine not running. Then just blip the starter but not enough to start. This should cause RoverGauge to do a reading of the AFM voltage with no air flow- this should be 6%

What is the idle AFM reading if it will run?

What is the CO trim voltage?

So far everything I see points at the AFM or wiring as this is the biggest factor controlling the amount of fuel.

Measuring fuel pressure if fraught with danger as the inlet vacuum controls the pressure on a running engine so its is lower than the 3 bar quoted. The only way to test it is to turn the fuel pump on with RoverGauge with just the ignition on and check its 3 bar.

If your plugs are still sooting up badly its nothing to do with a misfire as the car does not have lambda feedback that causes mis fuelling if the mixture does not burn correctly due to ignition.

Just generally with diagnosis its really important you double check your results, as one small error early on can take you up completely the wrong path so you may swap bits and add another fault in the process..

Hi, I've just measured with the most recent AFM installed.

RoverGuage = no error codes
Reading of the AFM voltage with no air flow - 5%
AFM reading at idle - wont start
AFM CO trim Voltage 1.06V
AFM Signal 0.4V
Fuel Pressure - retested with RoverGuage running pump full time (Ignition on) = 25PSI or 1.72 BAR

No sign of starting. I havent rechecked the wiring from ECU to AFM or Fuel Pump.

Thanks, Steve

[Belle427]

Fuel pressure looks low to me, test procedure here midway down page.
https://www.actproducts.co.uk/2011/lucas-14cux-fue...

[blitzracing]

It does look low, but not low enough to stop the engine running.

Back to basics. Try starting with some Easy start into the AFM intake and see if it will fire. This will at least isolate of its fuel or ignition. mind you the fact we get an AFM reading at all on cranking means you have a spark interrupt at the coil so that bits good.

Edited by blitzracing on Tuesday 28th November 10:59