Fuel ???? Problems with a friends Tamora

[mgwanderer]

Hi Guys, I am looking for help with a friends Tamora.

Problem
Engine starts but will stop after 5 secs unless I increase revs car is difficult to keep running and after 30 secs will stop even at 2000 revs plus engine is running lumpy
using the diagnostic software lambda sensor data is strange, starts at 0.06 (ignition on) and when it is at temp and kicks in it goes to 0.02 (both lambdas)

What has been tested / replaced

2 new Lambdas
MBE ECU (Swapped with one from a good car)
New Engine loom
Checked voltages
Checked Earthing
New plug leads
New fuel regulator
Swapped Lambda 1 and Lambda 2 over incase they were wrongly labeled
Swapped tps for a known good one

It would appear to be lambda / fuel orientated but I am running out of ideas (and seriously doubting my sanity)

Many thanks in advance

Clive

Edited by mgwanderer on Sunday 14th June 15:59

[jr6yam]

Air leak somwhere?

[mgwanderer]

Thanks for your input and I agree that its logical to think air leak but we have looked at these possibilities without success, and it would have to be huge to give us a reading on both Lambdas at close to 0. I would have thought that such a leak would be easy to find / hear. It would have to be a point that would influence both banks / lambdas as well and I would have thought that such a leak would be permanent probably affecting starting but as I said it starts and runs for a few seconds like normal.

Clive

[Penelope Stopit]

Can't see checked fuel pressure mentioned

[mgwanderer]

Thanks for the input, that is one of the things that we cannot check at the moment as we don't have a t-piece with the correct size but it is ordered and that will be checked. We did however fit a new pressure regulator just in case.

Clive

[nawarne]

Are you absolutely happy with the condition of the multipin connectors to the ECU?

They can oxidise and give rise to various poor running conditions. Remove the loom (male) side and use some contact cleaner on the pins.
On the diagnostics, what AFR readings are you getting. Is the crank position sensor still showing NO Fault?

Nick

[mgwanderer]

Thanks for your comments, diagnostics are showing no faults, we did check the diags were working by disconnecting a couple of sensors and they gave fault messages, with respect to AFR will check that again as I can't remember and for good order I will spray all connectors with respect to the lambdas and the ecu connectors.
I will update the topic when I have the AFR reading.

Clive

[Gladers01]

mgwanderer said:

Thanks for your comments, diagnostics are showing no faults, we did check the diags were working by disconnecting a couple of sensors and they gave fault messages, with respect to AFR will check that again as I can't remember and for good order I will spray all connectors with respect to the lambdas and the ecu connectors.
I will update the topic when I have the AFR reading.

Clive

Also worth checking the ignition coil for hairline cracks, mine failed allowing only 4 cylinders to run, was difficult to start and virtually impossible to drive.
You can check the exhaust headers on each cylinder are hot using a plastic tie strap, I remember the middle two pots being cold and the cat/s glowing orange Ecu was OK

Good Luck

[nawarne]

^^^Good shout regarding coil pack...They don't last forever - usually though, the early signs are a misfire on acceleration at about 2/3K rpm.

HT leads can also give issues...Maybe whop the lead cover off the cam cover and check for dampness. Alternatively, remove leads and dry out in a warm place for 12hrs.
Nick

[sunbeam alpine]

Could it be an airlock in the tank? Blocked breather? Maybe try running with the filler cap removed.

[hardtailer]

Disconnect both lambda sensors and start the engine. If it runs fine then I'd look into the ground wire of the lambda sensors and move them to battery negative post.
Another way dodgy grounds (on the sensor heater) manifests itself is through throttle position being all over the place/indicating open throttle whilst it is actually closed/idle position.

Edited by hardtailer on Friday 12th June 17:21

[mgwanderer]

Thanks guys for the help finding the in trying to find the cause but I am still struggling. I disconnected the one of the TPS units and it ran a little better, replaced the one that was disconnected and tried again, just the same as before so fault seems not to be in the TPS (grrrrrrrrrrrh).
Will keep on looking and will eventually (hopefully) be able to pass on the solution.

Clive