Dead at side of road

[madbilly]

The misfire was almost certainly the plug wire (HT lead this side of the pond), and you'd then have a cylinder not burning sending unburnt fuel down the exhaust causing the lambda sensor to tell you it was running rich. The ECU would probably try and compensate by leaning out the mixture, which would stop the other cylinders running properly, meaning it runs even rougher. I suppose it's possible the plug wire totally failed, and the engine might not restart on three cylinders if it's hot so you'd end up with loads of unburnt fuel in the cylinders. Changing the plug wires may well solve the whole problem, but I think you'll probably want to change the oil too now it's full of fuel.

An AA man reckoned my car had a blown head gasket, but I just think Elan exhausts look steamy as the car no other symptoms then or since.

[superbad]

OK, well. Just replaced all the plug wires. Car started, ran roughly for a couple seconds, then died. Won't restart. Elanscan data attached for a startup attempt. The obvious stuff (temps, pressures, etc.) all looks right. [The oxygen sensor is unplugged.]

I'm pretty baffled. This car was running quite sweetly a couple weeks ago.

[lotos]

She just doesn't want to leave your care and ownership

[superbad]

She shouldn't test me like that. I'm a phone call away from donating her to NPR.

[superbad]

After a handful of start attempts, there is A LOT of standing fuel in #1 and #2. There are little lakes of fuel down there, and if you turn the car over with the plug out, it gushes out of the spark plug hole. #3 and #4 are just damp. These are RC injectors, around a year old. There is absolutely no sign that it wants to fire up and turn over, apart from the couple seconds I got the other day. I tried unplugging the injector harness on 1 and 2 to see if it would fire on two cylinders, no change. The spark plugs are sparking.

Problem with the injector driver maybe? Desperate for some help with this. I can't be the first one to have this problem.

EDIT: Looking again, they are all quite wet. Seems like an excessive amount of fuel for cranking it over a few times. Fuel pressure regulator perhaps?

[DeanG]

I feel your pain. Unfortunately I can mostly give moral support.

I had somewhat similar problem. The car would always start although it didn't want to keep running. The monkeys at Criswells seemed to get it running by accident. Eventually the ECU, ignitions & base plate, oxygen sensor and injectors were replaced. The problem seemed to be an intermittently shorting injector that overheated the paired injector driver and perhaps confused the ECU.

Going to the Snowmass LOG I did have a problem with hard starting and stalling. It was the CAS.

Lotus of Denver where helpful.

Good luck.

[madbilly]

To clear the fuel from the cylinders and start from a known point first trip the fuel pump with the inertia switch in the battery area (is this where it is on RHD cars?). Hopefully you won't have to crank it until your battery goes flat! Then when you're sure all the fuel is out of the cylinders reset the switch, make sure everthing is as you would expect if you were starting it any old day, then have a go and see what happens. If it doesn't start after a few cranks don't keep going, you'll just end up with fuel flood again. Then it's time to start diagnoses. Ignition doesn't use the CAS, so we can rule that out, but the coil resistances should be checked (primary virtually nothing, secondary several thousand ohms), as should the injector resistances (2 ohm I think), and the spark plug gaps (0.8mm or 1.1mm depending on your plugs, make sure you know which you've got). Also check the HT lead resistances, but I can't remember how this can indicate problems - I did write up what I found mine to be in a thread several months ago but then I did change them as part of a misfire diagnosis. In the engine management manual it explains how to fault find the ignition circuit, so that's worth trying too.

I hope you'll excuse me if I sound patronising, but in my experience I'm grateful for all help and perspectives, I'd rather people assumed I hadn't checked something than otherwise.

[Brit-Car-Nut]

In the FED car, the Inertia switch is behind the driver's seat at the tunnel.

[superbad]

And the winner is... fuel pressure regulator. Put a new one in and it fired up immediately. Now to change the oil tomorrow. Thanks for the advices everybody.

A couple notes for future searchers:

1. When I pulled the vacuum line off the old regulator, fuel seeped out. So the internal membrane (or whatever is going in there) must have failed. This would have prevented any pressure regulation, and possibly even sucked fuel up into the manifold, explaining the massive flooding. The cylinders should not be full of fuel after a couple tries cranking the engine over unless fuel is being dumped in at a massive rate.

2. A couple FPRs show up on Rock Auto for the Isuzu. I went with the Airtex (made in the USA!). Despite the pictures that show up in various places online, the vacuum nipple comes off the end of the regulator, not the side where you want it. It interferes with the engine hoist bracket in that position, but if you bend it 90 degrees, and toward the RHS of the car a bit, it just barely fits under there.

[DeanG]

How did you figure it out?

[superbad]

Way too much fuel in all four cylinders. Excessive rich running is almost certainly what melted the cat the week before. Everything looked good in ElanScan, and there are only so many things that can cause uncommanded overfueling. Got lucky that it was the first one I tried.

[tigerdog]

fantastic detective work. Well done!