Starting issue

[Chimaeraman]

Chim 400 has ALWAYS started first time - no use of accelerator needed in the process.

Today started and car immediately died. Tried again with same result. Got into car and started and kept foot on accelerator. Car struggled to keep going - only achieved with boot firmly on accelerator and very very lumpy and wouldn't go above about 1500rpm but would then surge up to 4000rpm. Foot off pedal and car dies.

Any ideas chaps??

[Belle427]

Difficult to guess over the Internet, stepper motors are a big problem but I would expect you to be able to keep the engine running with the throttle with it sounding fairly healthy.
Maybe a large misfire, does it sound rough if you keep it at a certain rpm for a while?

[Steve_D]

Could be any number of problems but I will have a shot at failing fuel pump.

Steve

[Mutley00]

Just following up on what Steve says, if you turn the ignition on for 10-15 secs, without trying to fire up the engine, can you hear the pump whining and does it change note - decrease/slowdown/lower at all?

Good luck

[Classic Chim]

I’d agree sounds like fuel, possibly the regulator failed but more likely pump or it’s connections.

I’d start with taking a plug out and checking if it’s wet or dry. That might narrow down the rather large list of options a bit.

[Riff Raff]

Partially blocked or collapsed fuel filter?

[Chimaeraman]

Thanks all. Fuel pump sounds fine. I am no mechanic I have to admit!!!

Could it be an ECU (14CUX) problem - can they just fail overnight??? Would disconnect/reconnect be an option??

Just tell me if I am being a muppet I wont be offended!!!

[QBee]

Chimaeraman said:

Thanks all. Fuel pump sounds fine. I am no mechanic I have to admit!!!

Could it be an ECU (14CUX) problem - can they just fail overnight??? Would disconnect/reconnect be an option??

Just tell me if I am being a muppet I wont be offended!!!

It wouldn't start at all if the ECU had failed.

My car died half a mile after starting up one Friday evening.
It just stopped and that was it.

Called the RAC, they tested everything they could, but to no avail.
So I did a very TVR thing - I walked home.

Collected my trailer and went back and loaded the car (thankfully I HAD installed a manual winch when I refurbed the trailer).
Piled into the boot all the spares I had that were vaguely ignition or fuel related, including as luck would have it, a spare ECU I got in a £75 job lot of bits from a student who had sold his Chimaera to buy a V12 E Type. Saturday morning I set off to my TVR specialist 80 miles away at first light.

Long story short, after 15 minutes testing he said "it must be the ECU". So, having checked the connector, he took the ECU out and opened it, and there was loads of acid residue along the bottom edge and all over the fuelling chip, from two years ago when it had got soaked in acid when the battery had overheated and boiled over. Two years later it gave up. "Bugger" he said, "we won't get one of those today".

So I went to the car boot and dug out the spare ECU.
He swapped it over and it fired up first time.
He then swapped over the main chips - mine was a 5 litre, the spare ECU was from a 4 litre.
It then ran perfectly.

HOWEVER, if anyone's problem is ECU, it is much more likely that it is simply that the big ECU plug has come loose, than that it has failed completely.

[O mage]

Air flow meter harness/plug pins loose.

[blitzracing]

The 14CUX is tough as old boots, Ive seen very few fail. Water ingress is the biggest killer Id say, so any signs of corrosion on the PCB or connector means its got wet at some time. The lacquer on the board is pretty good, but you have to remove it when putting a socket so it really needs a blast of ignition seal again afterwards. A thing to look for on power on is the fuel pump on / off cycle, as if the ECU cant boot and run its microcode the pump runs all the time. In terms of external sensors, not one of them will kill the engine if it fails or disconnects, the ECU just drops into fallback mode to get you home. The weakest links to leave you stranded are the ignition amp, fuel pump and relays as there is no fall back system (Just don't tell Penelope about the relays )

[Oldred_V8S]

blitzracing said:

The 14CUX is tough as old boots, Ive seen very few fail. Water ingress is the biggest killer Id say, so any signs of corrosion on the PCB or connector means its got wet at some time. The lacquer on the board is pretty good, but you have to remove it when putting a socket so it really needs a blast of ignition seal again afterwards. A thing to look for on power on is the fuel pump on / off cycle, as if the ECU cant boot and run its microcode the pump runs all the time. In terms of external sensors, not one of them will kill the engine if it fails or disconnects, the ECU just drops into fallback mode to get you home. The weakest links to leave you stranded are the ignition amp, fuel pump and relays as there is no fall back system (Just don't tell Penelope about the relays )

That's the weak spot of the system you see Mark, clearly the circuit could do with at least another 10 relays
I think 10 was the number used in Penny's 18v charging circuit.