Ignition module
Ignition module
Author
Discussion

STE VR

Original Poster:

501 posts

237 months

Sunday 9th March 2008
quotequote all
Having been playing about under the bonnet I have somehow managed to create a lot of sparking and banging from the ignition module whilst re-crimping the coil wires. I twisted the coil round and somehow shorted something. Now when the engine is hot it will not tickover above 500rpm and intermittantly stalls.(it's fine when cold). Having searched the forums it looks like i've blown the module up but unfortunately i'm a little skint and would like to know where i could get a second hand/cheap one from????. This is my only car and a daily drive hence the need to find one asap.

ps it's a 95 serp 4.0litre.

Many thanks in advance
Steve

STE VR

Original Poster:

501 posts

237 months

Sunday 9th March 2008
quotequote all
I really hope so but have checked around it and all looks ok. Why would this only happen when the engine is hot??

Steve

GreenV8S

31,027 posts

315 months

Sunday 9th March 2008
quotequote all
You say it won't tick over above 500 rpm, are you saying that it *will* idle at 500 rpm? What happens if you open the throttle? From what you've said so far it doesn't really sound like an ignition fault. I'd be more inclined to suspect you've blown up the AFM or something like that. Worth checking the connections first, and also try completely unplugging the AFM and see if it runs better without it.

STE VR

Original Poster:

501 posts

237 months

Sunday 9th March 2008
quotequote all
From cold its fine, tickover 800 rpm. When warming up its fine, when it gets hot (90 deg) then it will randomly tickover about 500 rpm or just stall as soon as i dip the clutch when coming to a stop. When accelerating its ok but does not feel as crisp as usual. Maybe i'm just assuming its the amp cos this is where the sparks were from!

Steve

GreenV8S

31,027 posts

315 months

Sunday 9th March 2008
quotequote all
So it still drives OK?

In that case you can rule out a lot of nasty potential problems.

Get it up to temperature and idling steadily then pull the plug off the stepper motor.

If all the problems immediately go away, you know that's the cause. It's probably just dirty, or possibly has a wiring fault.

STE VR

Original Poster:

501 posts

237 months

Sunday 9th March 2008
quotequote all
Going for a spin right now to check!!

Cheers

Steve

STE VR

Original Poster:

501 posts

237 months

Sunday 9th March 2008
quotequote all
Ok, removing stepper when hot makes no difference. She revs up fine but doesn't feel very smooth when driving, not quite tho it's running on 7 but similar. Will not tickover for very long before revs die to practically nothing and then i get a big surge of revs(approx 1200 rpm) as tho the ecu is trying to adjust it then promptly followed by stalling. Restarts straight away but will not tickover again until cooled down???????????? banghead

GreenV8S

31,027 posts

315 months

Sunday 9th March 2008
quotequote all
There's something wrong, but hopefully nothing catastrophic. The fact that the idle is unstable with the stepper disconnected suggests that the fuelling is wrong. This could be because of a sensor fault. There's a slim chance that the ECU has simply dropped into 'limp home' mode because of a temporary problem so I suggest you reset the ECU by disconnecting it for 30 seconds and see if that helps. Most likely it won't help, or will only help temporarily, but it's worth a try.

STE VR

Original Poster:

501 posts

237 months

Sunday 9th March 2008
quotequote all
Thanks GreenV8S will give it a try. Just hoping with all the short circuiting i haven't done any damage to the ecu. just for info the car was absolutely fine before i went and done this so i am blinkered into looking around that coil/amp area for the reason. Do you know if the ecu has any protection on the inputs?

STE VR

Original Poster:

501 posts

237 months

Sunday 9th March 2008
quotequote all
Strange happenings...... whilst car hunting like mad and trying to stall i disconnected the afm, tickover became fine. reconnected afm and still tickover fine and drives very well with no problems woohoo How can this happen???????

STE VR

Original Poster:

501 posts

237 months

Sunday 9th March 2008
quotequote all
Ok now i know i'm really only talking to myself biggrin but my woohoo was short lived!! Just tried to start again but will not tickover, disconnect amf and all is well so it looks like i have blown up the amf!!! FFS

GreenV8S

31,027 posts

315 months

Sunday 9th March 2008
quotequote all
The ECU will run the engine without the AFM, I assume it is fuelling based on throttle angle. This won't be as accurate as load sensing via the AFM, but if the AFM is returning garbage it's probably an improvement. I think you need to get the AFM checked out. Unfortunately they're quite expensive, so I suggest you confirm this is faulty (for example borrow another and see if that cures the problem) before parting with the cash.

STE VR

Original Poster:

501 posts

237 months

Sunday 9th March 2008
quotequote all
Does anybody know how long i can run the car, in terms of damage, without the afm connected?

GreenV8S

31,027 posts

315 months

Sunday 9th March 2008
quotequote all
'95, so you've got cats? Ten minutes ish.

STE VR

Original Poster:

501 posts

237 months

Sunday 9th March 2008
quotequote all
biggrin............please be joking.....

blitzracing

6,422 posts

251 months

Sunday 9th March 2008
quotequote all
You can test the AFM very easily with a hair dryer. Remove the pipework, and put a DC test meter between the red/black wire and the blue / green wire. Then switch the ignition on. There should be about .3-.6 volts with no air flow. Then give the input side a good blast with a hairdryer on cold, the voltage should rise through several volts. Not a calibration check, but shows its basically working.

Mark

STE VR

Original Poster:

501 posts

237 months

Sunday 9th March 2008
quotequote all
No probs trying, that will have a go tomorrow. Ta

Steve

selnic

467 posts

298 months

Sunday 9th March 2008
quotequote all
Steve, If the AFM is knacked and you need a new one, worth giving these guys a try......
http://stores.ebay.co.uk/goldstar-international I bought a brand new one from them this week for £45 (plus £5 for 1st class delivery)the part number you require is ERR5198.
Nick

dwgriffith

436 posts

252 months

Sunday 9th March 2008
quotequote all
selnic said:
Steve, If the AFM is knacked and you need a new one, worth giving these guys a try......
http://stores.ebay.co.uk/goldstar-international I bought a brand new one from them this week for £45 (plus £5 for 1st class delivery)the part number you require is ERR5198.
Nick
In the ad it states the unit to be supplied will look different from the original but will fit, so are they supplying non-lucas copies? There have been several comments on the V8 forum reporting poor performance from undisclosed sourced far eastern manufactured AFM's.
The 35dlm8 distributor copies on ebay are of poor quality compared to the genuine lucas ones, I had 3 in all from different suppliers including RPI, they all went back without fitting them. They may, however, have worked fine but there was as much play in shafts as the one I was replacing.

selnic

467 posts

298 months

Sunday 9th March 2008
quotequote all
The unit which was supplied (and is now fitted and working) is as far as I know brand new and not recon, it is exactly the same as the OEM LR unit other than there is no LR logo on the side. With regards to them being made in the far east, so what, how many electronic products do you own which are made in england?