RRC 1988 V8 EFI cranks but won't start after refitting alternator

LanzaroteSteve · Dec 22, 2013

I've just replaced the brushes in my alternator and refitted. Now it cranks but wont start!!!
Battery is new and tests fine also tried jump leads but won't fire.
I can't see how the alternator could even be related to not starting as the truck started without any problems even when the alternator was removed for a few days. Tried disconnecting the alternator and still wont start.
Help please guys????

wammers · Dec 22, 2013

You have your answer then it has nothing to do with alternator. Look elsewhere.

West Slope Rover · Dec 22, 2013

Check out the connections on your coil.

LanzaroteSteve · Dec 22, 2013

It's just that yesterday, no alternator and starts, today refitted and won't start. Tightened up pas and alternator belt. Didn't touch another thing. Can anyone confirm that non of the wiring from the alternator could effect power to the fuel pump etc?
Is it possible to flood an EFI?

wammers · Dec 22, 2013

LanzaroteSteve said:
It's just that yesterday, no alternator and starts, today refitted and won't start. Tightened up pas and alternator belt. Didn't touch another thing. Can anyone confirm that non of the wiring from the alternator could effect power to the fuel pump etc?
Is it possible to flood an EFI?

That is a change in direction earlier you said it wouldn't start with alternator on or off. Could flood if it's injecting but no spark. Don't have diagrams for that model.

West Slope Rover · Dec 22, 2013

It's very possible to flood an EFI. Pull a plug and check to see if it's drenched in fuel. If so, pull 'em all and clean and dry them.

LanzaroteSteve · Dec 22, 2013

Will try pulling plugs and see if I'm getting a spark.
Also noticed that when the Alternator wasn't in the car I didn't get a battery light on the dash. Now that I've refitted and then removed again I'm now getting the battery light!!! I would think that without alternator I shouldn't get the light?

jamesmartin · Dec 22, 2013

you wont get a light on in the dash without the wire conected to the d+ terminal on the alt

Saint.V8 · Dec 22, 2013

Check ignition amplifier on the side of the dizzy too.....they can just all of a sudden fail (My 1993 3.9 just cut out all of a sudden whilst pulling into a car park one day...no warning nothing!)

wammers · Dec 22, 2013

jamesmartin said:
you wont get a light on in the dash without the wire conected to the d+ terminal on the alt

At least that bit of his refurb has gone well then.

LanzaroteSteve · Dec 22, 2013

Hmmm! So why am I getting a bat light when all connections have been removed from the Alternator? Sod's law one step forward and 2 back today!
Thanks everyone for taking the time to help me out though.

LanzaroteSteve · Dec 22, 2013

Checked again and I think one of the cables must have been earthed as I'm now not getting the bat light!
Pulled a plug and it's dry but I'm not getting a spark!
Where do I look now?

West Slope Rover · Dec 22, 2013

If you've been cranking on it a bit then there should be some sign of fueling on the plug. No spark means you need to start checking coil, ignition amp and maybe dizzy.

wammers · Dec 22, 2013

LanzaroteSteve said:
Checked again and I think one of the cables must have been earthed as I'm now not getting the bat light!
Pulled a plug and it's dry but I'm not getting a spark!
Where do I look now?

Go inside pour a whisky and relax for a bit.

Saint.V8 · Dec 22, 2013

The System needs a running signal from the coil through a resistor to tell the ECU the engine is cranking and it needs to introduce fuel...

If the coil isn't firing, the EFI ECU won't introduce fuel hence your dry plug.

Check coil connections, Rotor arm and Dizzy cap, if it has electronic ignition - the ignition amp, if not - the contacts inside the Dizzy...

The Dizzy reluctor ring air gap (if Electronic Ignition)

LanzaroteSteve · Dec 22, 2013

How do I check the coil with a multimeter? I've checked the connections and all looks fine. But want to double check with a meter before moving on.

LanzaroteSteve · Dec 22, 2013

No spark at the dizzy so now looking at faulty lead from coil to dizzy or coil faulty! Is there a separate fuse for the coil?

West Slope Rover · Dec 22, 2013

I'd clean and tighten up all the connections involved as well as cleaning up between the housing that holds the coil and the wheel well as I believe it is an earthing point. Don't forget about a bad condenser, either.

LanzaroteSteve · Dec 23, 2013

Found the problem and starts fine now.
I must have knocked a thin wire when I removed or refitted the alternator. The wire was the earth wire from the coil to the dizzy and it broke just after the plug connection it to the dizzy!
I found the problem by checking the voltage at the coil with the key in ignition on. Black probe on battery positive and red probe on the connections either side of the coil. They should both read approx 12v but I found the negative side connection on the coil was lower. Chased these wires and found the problem.
Just thought I'd post in case anyone else has a similar problem.
Also can't believe that a wire so fine could disable the car from starting! Must replace with new cable asap!
Thanks again guys for all the help

West Slope Rover · Dec 23, 2013

Cool!

RRC 1988 V8 EFI cranks but won't start after refitting alternator

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