Chimaera not firing?

[Bomber Denton]

Hi, I wonder if anyone could give me a pointer on the next place to look? With some time on my hands I have pulled my old Chimaera out for a fettle but at the moment it is not firing?
I have fuel pressure to the rail, I have pulsing to the injectors, I have spark but the plugs are dry.

Any ideas?

Thanks.

[Bristol ave fag]

Hi, Have you checked the pressure with a guage? can you hear the pump?

[Bomber Denton]

Pump is working fine, flow to injector rail, fuel squirts out from schrader valve on rail when depressed, electrical signal to injector. I don't however have a pressure gauge at the moment?

[blitzracing]

That makes no sense at all- you cant have pressure in the fuel rail and an injector signal, (how do you measure a 3 ms pulse unless you have a scope or noid light?) but no fuel. You can have 12v on the injectors, but they dont fire, as its a ground signal that opens them, not 12v being applied. Try a squirt of Easy Start.

[Bomber Denton]

Telling me it makes no sense. I have a Mac Tools Noid Light kit which I used.

The quest continues. :-)

[Belle427]

A sniff of easy start will probably tell you if it's fuel related.

[Bomber Denton]

Update, the car will fire with Easy Start so it is certainly fuel related.

[Bomber Denton]

Also, i have just tested fuel pressure to the rail and it is spot on, 30psi rising to 40psi on cranking.

[Steve_D]

Few questions.
When you used 'Start ya barsteward' did it just pop a little or did you get a short clean run? It could pop a little even if the timing was all over the place. A clean run would point to a reasonably sound ignition system and timing.

Were you getting nice readings with your noid lights?

Have you tested the MAF for correct voltages and resistances? If the MAF is duff (a fairly common fault) the ECU may be firing the injectors but not for very long due to duff info from the MAF. You 'may' be able to test run the engine with the MAF disconnected. Not sure on this one but Blitz may be along to confirm or deny.

Steve

[Penelope Stopit]

Did you have all the injectors disconnected when testing with a noid

If all injectors were disconnected there is the possibility that the injector circuits will drive a noid but won't drive the injectors

Anyway, stay cool calm and collected

There are times when it's not worth getting anoid

[blitzracing]

The initial few seconds and cranking dont use the AFM to measure the airflow, its a fixed fuelling pulse. If you have a massive air leak then this pulse may not provide enough fuel , but conversely if you have a small air leak it will start, and then die as the AFM takes over and the fuel is reduced as air is getting in somewhere else. The two sides of the V8 are independently fired by the ECU , so even if one side has failed electronically the other side should still be OK. You could have a weird fault on the ECU where the fixed pulse is not long enough to provide enough fuel to start, or possibly the engine temp sender is saying the engine is hot so its not adding cold start fuel. The fuel rail temp sender and water temp sender are the same device resistance wise, so you can do a simple ohms test on both on a cold engine and you should have near the same reading.

[Bomber Denton]

Update.

Tested the ohm outputs from the ECU which were correct, gave it another longer shot on the Easy Start and presto it came back to life! Had it running for a while now starting and ticking over fine!

Thanks all!!

[Penelope Stopit]

Now you're worse off than ever

If you haven't found the fault................................

Edited by Penelope Stopit on Thursday 9th April 16:54

[Belle427]

How long had it been standing?

[Bomber Denton]

Penelope Stopit said:

Now you're worse off than ever

If you haven't found the fault................................

Edited by Penelope Stopit on Thursday 9th April 16:54

Nope, running perfectly now.

[Belle427]

Gummed up injectors maybe, certainly a strange one.