no spark
Author
Discussion

stevo.elan

Original Poster:

27 posts

251 months

Thursday 13th July 2006
quotequote all
hi all, i have just re-built a 96 4.0l chimaera engine (badly ed cam) and after puting all the bits together i've got no spark and no voltage at the coil. i've put a new coil on and the fuel pump primes, i get dash lights and it turns over but still no spark. the fuses are good and the earth is good. i've double checked all the conections and fully charged the battery. open to sugestions?

thanks in advance for a well pissed off, stevo.

p.s given that this is the same engine i have rebuilt in my dads p6 elan turbos are way easyer to fix.

shpub

8,507 posts

302 months

Thursday 13th July 2006
quotequote all
It's an electronic coil with an internal pick up and external amplifier. Worth chceking that the all the connections are still OK and that power is going to the appropriate bits. It doesn't have a contact breaker!

v8 racing

2,064 posts

281 months

Thursday 13th July 2006
quotequote all
You have got the terminals on the coil the right way round have you? sorry if i am telling you to suck eggs but there is a black wire which is the ign live to the coil, a lot of people think this is a ground?

pupp

12,973 posts

302 months

Thursday 13th July 2006
quotequote all
At the risk of stating the obvious, is the rotor arm present and installed properly...ie fully home. Are the RA contacts ok (sorry)? Is there HT available on the king lead into the distributor (try arcing it to earth)? Check for integrity of the king lead (has it rubbed on anything so that it is leaking to earth along its lenght somewhere... maybe try cranking the car in the dark to look for stray sparks)? As the coil is new, I'm assuming the primary and secondary resistances check out (worth switching back to the old one as a reality check)? Is the ignition module connected properly (polarity not reversed)? Worth checking the output from this as the engine is turned... measured voltage should switch (does the job of traditional points). I'm not sure what the 'trigger' mech is as I've never delved in that far, but might be worth checking any sensor or 'chopper' is present (or gapped properly) if these were disturbed when the cam was replaced? Is the distributor properly home and turning with the engine?

Good luck

Griffter

4,143 posts

285 months

Thursday 13th July 2006
quotequote all
If there's no voltage at the coil (I assume you mean no 12v across the LT terminals with ignition on) then surely the problem must be in the loom to the coil? Possibly the ignition amplifier is failing, shorting the coil terminal(s) to ground, but I doubt it. I'd start by doing continuity tests to the LT coil wiring.

stevo.elan

Original Poster:

27 posts

251 months

Thursday 13th July 2006
quotequote all
You have got the terminals on the coil the right way round have you? sorry if i am telling you to suck eggs but there is a black wire which is the ign live to the coil, a lot of people think this is a ground?


black? positive? joking? i think i've got that going to the - on the alternator. D'OH!

pupp

12,973 posts

302 months

Thursday 13th July 2006
quotequote all
stevo.elan said:
black? positive? joking? i think i've got that going to the - on the alternator. D'OH!


I gather it's going now?

Edited to add 'well done'

Edited by pupp on Thursday 13th July 22:57

stevo.elan

Original Poster:

27 posts

251 months

Friday 14th July 2006
quotequote all
result! it makes noise, now i just have to stop it sounding like a bag of spaners.
thanks for the help guys, i knew it would be something stupid.

pupp

12,973 posts

302 months

Friday 14th July 2006
quotequote all
stevo.elan said:
now i just have to stop it sounding like a bag of spaners.


Hey, congrats... you've turned it into a Cerbie!

chassis 33

6,194 posts

312 months

Friday 14th July 2006
quotequote all
Just to help future generations looking for a spark...what was it in the end?

Regards
Iain

Blipi

2,355 posts

267 months

Friday 14th July 2006
quotequote all
Coil terminals. Wrong way around. Great TVR design.

chassis 33

6,194 posts

312 months

Friday 14th July 2006
quotequote all
...but arent the electrical terminals inverted male/female on the coil so you can't get them inverted?
And don't knock TVR, the coil and loom is lifted straight from a Landie!!!
Regards
Iain

Edited by chassis 33 on Friday 14th July 15:10

GreenV8S

31,021 posts

314 months

Friday 14th July 2006
quotequote all
I expect it'll vary, but for example on mine both LT terminals are studs.

v8 racing

2,064 posts

281 months

Friday 14th July 2006
quotequote all
chassis 33 said:
...but arent the electrical terminals inverted male/female on the coil so you can't get them inverted?
And don't knock TVR, the coil and loom is lifted straight from a Landie!!!
Regards
Iain

Edited by chassis 33 on Friday 14th July 15:10

I think reading between the lines he had connected the black (which is coil live on serp engines!!) to the tacho output on the alternator and vice versa, they are both close together and the same terminals so easily done

stevo.elan

Original Poster:

27 posts

251 months

Friday 14th July 2006
quotequote all
[/quote]
I think reading between the lines he had connected the black (which is coil live on serp engines!!) to the tacho output on the alternator and vice versa, they are both close together and the same terminals so easily done[/quote]

that was it exactly. it comes off the loom at the same place as the lt wires. 4 whites/wh grey and one black, with two of the whites male and two female i put them all on the coil and the spare black on the alternator negitive terminal. but as we know hand build britsh sport car dont work like that.

v8racing i owe you a pint, stevo.

Edited by stevo.elan on Friday 14th July 19:44