Ignition Amp Testing? Still won't start...

[frubes]

Car is still sat on my drive... Grrr!!! It turns over still but won't catch, doesn't sound like its thinking about catching.

My friend came round to see the car for the first time, but didn't I couldn't it still.

I was able to check the spark from the lead on the block and seemed to be sparking, not sure on strength or timing though.

My friend reckoned he could smell the fuel coming through, so inclined to think ignition still.

Previous posting, people said to check ignition amp on dissy. Is there a way i can test it before i replace it? I have my multimeter now so can check resistance/voltages etc??

[frubes]

Does anyoe know the part number of the ignition amp?

Also I read quite a good post with similar symptoms. The chap talks about checking the spark and it being orange rather than blue. Did he check this by removing a plug and then reconnecting the lead and seeing the spark at the gap? or just the spark between the lead and the earth, i.e the block as I did above?

Edited by frubes on Sunday 29th March 09:37

[jmorgan]

I had a whole load of grief with this. But it would start, just not go when you gave it a nudge. The only way I found out to prove it was to change it.

Without being qualified, check the connectors, there are apparently a two (??) versions.


Edited to add

Wished I had that info from Honestjohntoo when I had the problem, better save this for posterity.

Edited by jmorgan on Sunday 29th March 10:25

Edited by jmorgan on Sunday 29th March 11:39

[tempus]

What is your car and what year ?Tempus

[chedder]

Intermotor 15410 is the part number

[honestjohntoo]

If youve got sparks its probably something else but first this procedure could be adapted to diagnose the ignition during cranking.

First, your circuit will be something like this.



Guaranteed Foolproof Intermittent Ignition Fault Finder. Please notify of errors/omissions.

Rig up two 4/5 watt 12 volt bulbs (or better still, 2V, 15mA LED's + 680 ohm resistors) on test leads into the cabin and connect one between coil +ve and earth and the other to coil -ve and earth. Mark the bulbs POS and NEG. Beware cables dont foul hot/moving parts.

Crank the engine and observe:

POS sensing the ignition input voltage is permanantly on,

AND

NEG sensing the pulsed voltage across the Ignition Amplifier flickers in sympathy with engine rpm, or is dimly lit (LED's flicker better).

note what happens when cranking.

If POS and NEG go out together there is an open circuit interruption of the 12 v feed such as a faulty wire/ignition switch,

OR

A short on the same circuit due to burned insulation.

If NEG comes full on the Ignition Amplifier (due to excess internal heat) or its associated wiring/earth has failed in open circuit mode,

OR

The pulsed input (ie Hall Effect or Reluctor) to the amplifier from the dizzy has failed or the associated wiring is faulty/shorting to earth,

OR

The Coil has failed in a short circuit mode (unlikely cos it would surely kill the amplifier methinks?)

If NEG goes out the Ignition Amplifier has temporarily failed in short circuit mode due to excess internal heat,

OR

the local wiring is shorting to earth,

OR

The coil has failed in open circuit mode due to insulation breakdown or internal heat

If POS stays lit and NEG show signs of flickering instability not sympathetic with engine rpm, then the Ignition Amplifier or its connections are on the blink.

Moving on

1 check ignition timing.

2 Check the engine running signal from coil negative goes to pin 1 of the ECU via the 6800 ohm resistor.

3 Check components such as coolant temp sensor, AFM, etc.

4 Check for rougue air leaks and connector corrosion prob.

Get everything you need from the archive index found here:

http://www.vintagemodelairplane.com/pages/Rover_Te...

Edited by honestjohntoo on Sunday 30th June 13:14

[B-Reight]

Are you sure you have fuel? Remove the hose off the cold start injector and stick the end in a suitable receptacle (empty jam jar), turn the ignition to the on position (don't start the car) and press the airflow flap by hand. You'll then know if you've got fuel beacause if fills that jar bloody fast!

If you do have fuel you may well have flooded the engine with all that non productive cranking, you'll need to disconnect the fuel pump fuse and crank the engine to clear it.

[GreenV8S]

If you've been trying to start the engine and there is fuel going in then it's almost certainly flooded by now regardless of anything else that's wrong. I recommend that you take a plug out and check whether it's wet or dry. This will tell you for sure whether you have fuel going in.

Another very useful test is to put a passive strobe (an ordinary cheap unpowered timing light does the job nicely) in series with one of the HT leads. This will show whether you're getting a spark while cranking.

Another useful test is to put a test lamp or meter across one of the injectors. The best way to do this is by buying a pair of male/female mini-power timer connectors and make up a short extension with a 12V LED connected across (get the polarity right). You can also buy ready-made NOID test lamps that do the same thing.

[frubes]

Its a 350i 1998.

The plot thickens... I've had a plug out. There's definately fuel getting in, the plug was wet with fuel. I took the fuel pump fuse out and turned it over a fair bit. No luck.

Anyway I said I had tried the spark on the block from the cap of the lead and it was sparking orange. So while I had the plug out I put it on the lead and turned it over again and.... NO SPARK!!!??

Bit weird I thought. The plug looks fine, not brand new, but not degraded, or funny coloured. Therefore back to quality of the spark, could the coil be putting out enough to spark on from lead to block, but not at the plug?

Bloody motor factor sold me the wrong coil, and now closed, so will have to wait.

To throw one more thing into the mix, the coil is a bit oilly on the outside? Leaking? Overheated?

[GreenV8S]

frubes said:

Anyway I said I had tried the spark on the block from the cap of the lead and it was sparking orange. So while I had the plug out I put it on the lead and turned it over again and.... NO SPARK!!!??

Bit weird I thought. The plug looks fine, not brand new, but not degraded, or funny coloured. Therefore back to quality of the spark, could the coil be putting out enough to spark on from lead to block, but not at the plug?

First of all I suggest you disable the fuel pump. If you have fuel getting in then regardless of what else is wrong the cylinders will be flooding. You want to leave the pump disabled most of the time, just enable it briefly for say 10% of the time to stop the engine drying out completely. Once the engine starts making signs of life you can think about putting the fuel back into the equation.

It's not clear exactly what you did in the two tests.

The first test would be to disconnect the king lead from the centre of the dizzy cap and show you get a spark from there to ground. If that works then reconnect to the dizzy and do a similar test with one of the HT leads. This will be harder since the plug caps are well shielded, a common trick is to poke a screwdriver inside the cap and get a spark from that to earth. If you have a plug out, or a spare plug, it's better to connect the HT lead to the plug, make sure the body of the plug is well earthed, and confirm you get a spark across the plug.

[frubes]

Yeah DUH!!! I didn't ground the body, not going to spark is it... Bit thick, I need to try that again.


HT lead def sparking to earth.

What do you mean by disconnect pump all but 10% of the time?

[GreenV8S]

frubes said:

What do you mean by disconnect pump all but 10% of the time?

I mean as you're repeatedly cranking the engine over for your testing, only have the fuel pump enabled for one attempt in every ten.

[frubes]

Thanks GreenV8S, I see now. Ok. Fuse out.

Tried again with the plug. Sparking very orange... Should be white/blue i'm told.

I still think coil. Does anyone know what the part number is?

[GreenV8S]

Landrover PRC6574 or Lucas DLB198 or Bosch 0221 122392. Your existing coil probably has a part number on it too.

ETA These are all for unballasted coils. I don't think the wedges had ballasted coils, but it would be as well to check.

Edited by GreenV8S on Sunday 29th March 20:13

[B-Reight]

Andrew Page do the Bosch coil, its about 60 quid if i remeber rightly. Expensive but much better than the intermotor equiv most places stock.

Have you inspected the cap and rotor arm?

Do you get a decent spark from the King lead?

Edited by B-Reight on Sunday 29th March 20:11

[frubes]

Not checked the king lead as it was sparking at the HT lead. The dissy cap looks new. The thing is it was running fine and started first time everytime, and now is dead.

He had been misfiring a bit when warm, and read that this could be the coil getting hot. Which makes me think it has now failed.

Annoying because I really wanted to go for a drive this weekend.
Thanks for everyones comments so far by the way.

[tempus]

Assuming it is an `88/89 the module is a Lucas DAB121,Intermotor 15420,this was a magnetic pick up unit with two pins at 90 deg. to each other,if this is correct the coil is Int.11410,Unipart GCL211.Another thing to check if this part is correct is the magnet in the dist.as they do lose their magnetism and fail to trigger the spark properly.Tempus

[frubes]

I think I'll just change the coil and the ingnition amplifer then and see the state of the spark then.

I've now been told two different Lucas part numbers for the coil???

Tempus is right I do have the ignition amp with 2 plugs as right angles. So shall i go with that coil?

I presume it is a ballasted, 12v coil? Are they not all the same?

[tempus]

If the amp is correct then the coil is correct,it is an electronic ign. coil and not the same as an ordinary coil.ballasted or not.The coil is about £17 plus vat (intermotor) and the module £26 +vat (intermotor).Tempus DLB 198 is good as well

Edited by tempus on Monday 30th March 11:34

[honestjohntoo]

frubes said:

I think I'll just change the coil and the ingnition amplifer then and see the state of the spark then.

I've now been told two different Lucas part numbers for the coil???

Tempus is right I do have the ignition amp with 2 plugs as right angles. So shall i go with that coil?

I presume it is a ballasted, 12v coil? Are they not all the same?

One wonders if the simple test process I described using a couple of 12 volt bulbe would not indicate if any of your components are actually faulty or showing intermittant?

However, reading thro the posts you seem to have established beyond question that you do have sparks and the main issue is that it simply will not catch, so I repeat my suggestion to move on.

1 check ignition timing.

2 Check the engine running signal from coil negative goes to pin 1 of the ECU via the 6800 ohm resistor.

3 Check components such as coolant temp sensor, AFM, etc.

4 Check for rogue air leaks and connector corrosion prob.

To which I would add.

5 as suggested, disable the CSI to prevent continuous further flooding, these systems are quite capable of firing without the help if CSI on all but the coldest of days.

6 Check if the injectors are actually firing whilst cranking by putting a bulb or volt meter across an injector whilst cranking and watch if it flickers.

7 Move to tha dignostic process before the random replacement of components fails to work and simply empties the bank balance.

8 borrow a good ECU to confirm or eliminate the most expensive possibilty.

Edited by honestjohntoo on Monday 30th March 11:32