All but actually starting - Immobiliser?

[GFro93]

Hi all,

I have seen a number of posts with a similar problem to the one I am having on my '93 Chimaera. The engine died on me during a drive and now won't start. It very nearly starts every time, turns over and occasionally fires, but never actually gets there.

The fuel pump is priming and getting power, the stepper buzzes, I have changed 'those' relays for new ones and checked the inertia switch in the glove box. unplugged the ECU and plugged back in and same with the battery. The only thing I haven't checked or been able to do is bypass the immobiliser?

Is there anything else it could be?

Thanks!!

[ez64]

If your firing and stuttering the immobiliser has allowed the ECU to start and fuel is pumping.

Going through fuel pressure, spark, timing, grounds, air flow reading, 100a fuses + voltage check and Rovergauge output methodically would be my first port of call. Ignition amplifier might not be a bad quick jump to though if your feeling lucky.

[nzflash]

I had the exact same issue earlier this year. Mine was a failed coil with no warning.

The other common failure point is the ignition module.

If you know someone with another chimaera you could try swapping the coil and ignition module assembly, only takes 5 minutes to do.

[QBee]

It will be spark or fuel, and a sudden almost complete failure, but still sort of trying to fire, to me sounds more like spark than fuel.
Agree with the above re coil or ignition amplifier,
Also try taking out a plug, and with it connected to its lead and earthed on top of the engine (don't hold it with your bare hands!!!), get someone else to operate the key and see if you have a decent healthy spark.
Another thing to look at is the lead connections from coil to distributor, and the distributor internals.
Something is stopping enough spark from getting to all your cylinders.
The car will quite happily run on 6 cylinders, so it's unlikely to be anything beyond the distributor.

[Mutley00]

QBee said:

Also try taking out a plug, and with it connected to its lead and earthed on top of the engine (don't hold it with your bare hands!!!), get someone else to operate the key and see if you have a decent healthy spark.

Cant recommend these things highly enough https://www.ebay.co.uk/itm/172099079072?ssPageName...

[Penelope Stopit]

Mutley00 said:

Cant recommend these things highly enough https://www.ebay.co.uk/itm/172099079072?ssPageName...

Very good aren't they

[GFro93]

Thanks for all the suggestions,

I have tested the coil and ignition amp plug all showing 12v. I have changed the ignition amp, mine is on the side of the distributor rather than behind the coil but no luck either. Tested for a spark which looks good, albeit on only the first 2 sparkplugs - is it necessary to check all of them?

Is it now a case of making my way through the wiring loom for a possible breakage?

Thanks!

[Penelope Stopit]

Check fuel pressure and ignition timing

[blaze_away]

Yes its a good idea to check that all your plugs are getting a spark. ie if you have a jump lead clamp a plug in one end the other end clamp to an engine bracket then test each plug lead for a spark.

1.
If they are all sparking then pull each plug out and check gap and cleanliness and see if the spark is happening at the plugs.

OR

2.
If they are not all sparking go take a look at diatributor cap, rotor arm, ht leads.

Then report back for more help.

[Penelope Stopit]

Good advice blaze_away

As blaze_away comments, check all plugs first, don't take anything for granted

If all is good check fuel pressure and timing in whichever order is easiest

Oops, jumped the gun there

[nzflash]

Further to my above response, my car was getting good voltage and on bench test by auto electrician all looked ok. The issue was when the coil was under load it couldn't deliver a healthy spark quick enough.

Still recommend changing the coil. If nothing else you'll end up with a spare on the shelf.

[Penelope Stopit]

nzflash said:

Further to my above response, my car was getting good voltage and on bench test by auto electrician all looked ok. The issue was when the coil was under load it couldn't deliver a healthy spark quick enough.

Still recommend changing the coil. If nothing else you'll end up with a spare on the shelf.

Throw parts at it?

[Classic Chim]

Does the engine bay smell heavily of fuel after a cranking session?
If not then still consider fuel starvation.

If the car is due a 5000 mile service maybe do it early and replace ign amp/ coil etc as some preventative maintenance as with plugs etc.
If car stopped whilst driving you obviously have a failed system so do it systematically until it starts.
A shed way to check fuel rail pressure exists would be to prime pump, use a rag and cold engine, and push the valve in. If fuel pumps out 4ft you have both fuel and pressure