resistance of an injector

[chirpychimpy]

Car died, got towed home, AA suggested it was a fuel problem. Have checked fuel up to the injectors, no problem, checked for pulsing ...okay, checked for power to here there and everywhere powers getting everywhere finally put meter onto the terminals on the injector to get a resistance measurement and all 4 injectors show a final reading of zero.

Q.what reading should I get off an injector ?
Q what would cause all four injectors to fail?

any help gratefully appreciated

not so chirpychimpy

[Doggy]

Petrol? Diesel? Which engine?

Helps if you put it in your signature, (then we'll ask different, equally stupid questions).

Ah, belay that! It's a 110 as stated in your profile.

2.2 HDi injectors are about 80 ohms each, 110's aren't the same, but should be something similar. (The ecu's gonna fling 80 Volts at them, so they're not going to be much less than this). Are you sure about your test equipment / methodology?

[chirpychimpy]

I put the probes of the meter onto each of the injector pins, it gave a few numbers then went to zero? one point that has been raised to me this evening is to look at is the camshaft sensor? any thoughts? i don't really know why the camshaft sensor would that stop the injectors from showing a resistance? would the camshaft sensor if faulty stop the engine dead? ohhh all these questions. Basically I was driving the car and the engine cut out totally. the car is 2ltr hdi 110bhp lx estate v reg . putting a code reader on it , it comes up as p0200 injector circuit malfunction trying to find the actual fault is pulling this chimps hair out!

[Doggy]

Try repeating the measurement, then swap the probes over and see if you still get the same, (in case they have an integral diode to absorb the reverse-voltage spike on de-energising).

I suspect this won't be injectors as there are 4 of them, driven by two separate ecu power supplies, you're probably looking for a single fault.

I read that the camshaft sensor is only used in the injector flow correction algorithm, (but don't know this for a fact). It may be more likely your crank sensor is at fault, as I've heard that without this signal it won't inject anything.

Definitely worth a careful examination of both, you might see something amiss.

[mjb]

I suspect this won't be injectors as there are 4 of them, driven by two separate ecu power supplies, you're probably looking for a single fault.

Bang on. When my car died and it reported problems with all six injectors and a whole host of other faults, I knew straight away that I needed to be looking elsewhere (and indeed, the fault lay with a failed relay box in the ECU housing caused by a bad body earth.

I read that the camshaft sensor is only used in the injector flow correction algorithm, (but don't know this for a fact). It may be more likely your crank sensor is at fault, as I've heard that without this signal it won't inject anything.

On petrols, the crankshaft sensor tells the ECU when to apply fuel and when to apply spark, so without it you get complete engine death. I don't know about diesels though.

One way to test the ECU's reading of the crankshaft sensor is to watch the rev counter when it dies. If it falls to zero while the engine's still turning, then the sensor (or something it depends on - fuse, wiring, etc) is duff.

I don't have time to grab the wiring diagrams, but I suspect this could well be a fuse or relay fault.

[chirpychimpy]

Update! car still not running. changed crankshaft and camshaft sensors no joy. tried resistance test again on injectors swapping probes on the elec pins all I get is 0.00 on all four injectors I have now run out of any idea where or what to check next.

Any suggesstions gratefully appreciated

very unhappy chimpy

[madmadmax]

try cleaning the fuel pressure regulator on the back of the pump two t30 and it pop out, asuming is got a bosch pump that is.

[chirpychimpy]

Mind boggling ! fuel pressure is 300 BAR, injectors all pulse, cam and crank sensors working, blocked EGR valve off (no difference) and finally, car would not start on brake cleaner being squirted into the inlet manifold.

Any ideas anyone Please

desperate chimpy

[chirpychimpy]

Mind boggling ! fuel pressure is 300 BAR, injectors all pulse, cam and crank sensors working, blocked EGR valve off (no difference) and finally, car would not start on brake cleaner being squirted into the inlet manifold.

Any ideas anyone Please

desperate chimpy

[Doggy]

Only the more desperate measures:

Timing belt snapped?
Turbo collapsed?
No compression?

[chirpychimpy]

timing belt is okay, I have yet to make sure that the timing is okay but the car wouldn't stop dead if it jumped 1 tooth, there are certainly no un-towards noises from the engine when turning it over so I believe that the timing is okay.

compression, hmmm that I am unable to check as I don't have a compression tester (yet) if there was lack of compression on one cylinder would the car still run though and the chances of losing compression on more than one cylinder at the same time, what is the chances of that?

turbo, if that collapsed would that stop the engine dead? and if it did collapse wouldn't there be some noises??

a gloomy but appreciative chimpy

[Doggy]

When you added the brake cleaner, could you tell if it was being drawn into the engine?

Alternatively, can you tell if it's pushing anything out of the exhaust?