Starting issues

[AdzTVR]

Good Morning All,

Having a frustrating issue with my 4.0 Chimaera....it won't start! I took her out for a drive last week and after about half a mile she started to cough and splutter and then completely cut out. After 5-10 mins I managed to get her going again and made it home but she was running rough almost as if it wasn't running on all 8. Left the car for the remainder of the day as had places to be, came back to have look the next day and it wouldn't start. Kept trying and eventually it started but immediately cut out then failed to start again,the stater motor fired up but not so much as a cough from the engine. This is now all it does, 1 in every 10 times I try to start it will fire up but cut-out almost straight away. I have been through the below so far but wondering if anyone has had a similar issue or can point me in the right direction?

Battery replaced (I did try a jump start on the old one but did the same thing)
100 amp fuse checked (Both in the passenger foot well and under the car)
Replaced both ECU and Fuel pump relays
Checked all HT leads seated correctly
Check rotary arm and distributer cap

I did wonder if this could be an immobiliser issue but I can hear the fuel pump prime and was under the impression if the immobiliser was on then neither the starter motor or fuel pump would work. The car was only serviced in December and was running fine until last week, the only change I have made is re-wiring the light switches after the wires all fell off on removing the radio surround, and all lights are now working as normal.so now am i thinking could this be a coil issue? There is a spark as it will fire but could it be that it's on it ways out hence why it's cutting out? or perhaps the fuel pump is dying and it's fuel starvation, i did pop a plug out and they were wet and I can smell fuel?

Any advice anyone can give me will be appreciated, desperate to get her sorted before next weekend.

Thanks

[black_potato]

You have fuel then.. so spark is next. Sounds like the battery is good as well so Dizzy would be my next place of call.

[Chimp871]

spark - check you have good spark in the king lead, if yes then check you have a good spark at the HT leads, if no then suspect dizzy cap, rotor arm, possibly amplifier module.

Best way is to remove the 2 relays (as you have) and turn her over watch for spark.

It's also a good idea to check you have 12v going to ignition coil - using multimeter put one probe on negative (eg coil bracket) and the positive on one of the coil terminals - turn ignition to start position (but do not start) check volts, then put probe on the other coil terminal and check volt. Should be 12v.

You should remove the plugs and clean them if wet.

Let us know how this goes, you won't be alone in this scenario.

Edited by Chimp871 on Monday 5th February 18:14

[AdzTVR]

Thanks for the advice guys, i had already purchased a new dizzy cap and rotary arm as mine do look a little worn. I will get the multimeter out tonight and check the voltage on the coil and report back with my findings!

[AdzTVR]

So I measured the voltage at the coil and got 11.5V, also tested the king lead spark and couldn't see that it did spark! Want to try it again and was on my own last night and was slightly tricky getting the lead to stay put and turning the key at the same time!

[pb450]

Have you checked the fit of the king lead into the coil? Ask how I know this can be a problem! Really simple one but this can cause grief if not a good fit. In my case, the arcing buggered the end of the coil before the problem was diagnosed. New coil, (could have been avoided) end of problem.

[AdzTVR]

I did check it last night, it's on as tight as it can be and didn't see any damage to the connector on the coil. I now have a new dizzy cap and rotor arm so will pop them on tonight and see if that improves things, faling that I might look to replace the coil

[N7GTX]

If there is no spark from the centre lead on the dizzy cap when you place it about 1/4" from the engine - lifting eye, block itself, mounting bracket etc - then you should concentrate on the coil or ignition module.
Chimp 871 had some corrosion under the dizzy cover inside so if you have the cap and rotor arm off a simple job to lift it off and have a look.
Check if you have battery voltage - around 12 volts to the coil.

[AdzTVR]

So re-tested the king lead and got a spark, still only getting 11.5v on the meter though, not sure if that matters. Replaced the dizzy cap and rotor arm as they both did look worn, but still having the same same problem. Not sure what to try next, ignition amplifier?

[N7GTX]

The voltage you get at the coil will be similar or slightly less than across the battery. So you have fuel to the plugs as they are all wet. You have a spark at the centre lead. Is it a strong blue one?
Once the plugs are wet you have to remove them all and dry them off. I use a blow torch to heat the tips up which gets rid of all the fuel and also helps a little on starting. Use the gas cooker if you don't have one.
Refit the centre lead on your new dizzy cap and new rotor arm and fit a dry plug to a lead and lay it on the engine. Ensure all the plugs are out as this will allow faster cranking. Crank it over and see if there is a good spark on the electrodes. If there is, try another lead just to be sure.
Once all the plugs are nice and dry, refit them all and try again. The battery needs to be in a good charged condition too.

[Chimp871]

Strong fully charged battery is a must.

It doesn't sound like coil but try the above first. Possibly amp.

My problem was that the reluctor ring was rusty and not contacting the electromagnet properly. You need to remove the cover under the rotor arm and check for clearance between a sprocket and the electromagnet of 0.25 mm.

I'm not sure this is your problem, I feel mine was unique. At least its a free check.

[AdzTVR]

So managed to get a few more bits done this weekend. Removed and cleaned all plugs, replaced HT leads. On re-testing the coil centre lead I get one spark and then nothing. Have ordered a replacement coil and ignition module so will see if that resolves the problem.

[AdzTVR]

Have now fitted a new ignition coil and module but still getting the same issue After fitting new parts on turning the ignition on I couldn't hear the fuel pump prime (First time this has happened) I check the relays and tried again and again and on the 4th/5th attempt I could hear it prime. First attempt to start car just cranked as it had been doing but didn't start, on the 2nd attempt there was a cough as if it wanted to start but failed to and then back to the just cranking.

So I have now replaced the HT Leads, Spark Plugs, Dizzy Cap, Rotor Arm, Coil and Module and both the ECU and Fuel Pump relays. The battery is brand new and properly charged so the only thing I can think of is that there is an issue with the immobiliser.....but wouldn't have the first idea of how to prove this!

[Steve_D]

If the problem is still lack of spark then the immobiliser is not the issue as it is not connected with the ignition.

If you still have no spark on the king lead (lead from coil to dizzy) then the only elements in the equation are:-
+12 v at coil
connection between coil negative and amp.
Coil
Connection amp to earth
Amplifier
Connections (2) between amp and dizzy pickup
Dizzy pickup
Pickup adjustment (gap)

Steve

[blitzracing]

Oh boy- the complex way of fault finding by throwing parts at it never goes well. Take two steps backwards--- Remove the dizzy cap and plastic shield over the dizzy trigger head. Rotate the engine until one of the lobes lines up with the trigger coil. Remove the king lead from the dizzy, and place the end about 1cm from the chassis with some tape. Turn on the ignition. Get a screwdriver, and jab between the rotor and the trigger head air gap and see if coil produces a spark- If not find a magnet and stick it to the side of the screwdriver near the tip and try again. This will produce enough of a trigger signal to fire the amp and coil. If there is no trigger, remove the amp and resistance check the trigger head connections- its basically a coil of wire so wont be more than a few k ohms at most. Open circuit means you have a break. Rust on the rotor has no effect, and wont stop it working. We know you have around 12v on the coil, so the only other point of failure is the connection to the amp from the coil. You can unplug the amp, and try shorting the -ve side of the coil to ground with a wire and see if you get a spark. It wont be as good as the one from the amp as you dont have the required capacitance for a full voltage, but you should still get something HT wise.

Just as a general clue as to whats going on- the ECU needs a good trigger pulse from the negative side of the coil as its switched to run the fuel pump. So your test with a screwdriver should also fire the pump for a couple of seconds.

Edited by blitzracing on Wednesday 14th February 13:40

[AdzTVR]

Thanks for advice chaps, will check the items mentioned tonight and see what results I get. I normally hate throwing parts at a problem but given most of mine looked pretty old and battered I thought it was worth a shot, I was deperate to get her running for the weekend!

[Penelope Stopit]

blitzracing said:

Oh boy- the complex way of fault finding by throwing parts at it never goes well. Take two steps backwards--- Remove the dizzy cap and plastic shield over the dizzy trigger head. Rotate the engine until one of the lobes lines up with the trigger coil. Remove the king lead from the dizzy, and place the end about 1cm from the chassis with some tape. Turn on the ignition. Get a screwdriver, and jab between the rotor and the trigger head air gap and see if coil produces a spark- If not find a magnet and stick it to the side of the screwdriver near the tip and try again. This will produce enough of a trigger signal to fire the amp and coil. If there is no trigger, remove the amp and resistance check the trigger head connections- its basically a coil of wire so wont be more than a few k ohms at most. Open circuit means you have a break. Rust on the rotor has no effect, and wont stop it working. We know you have around 12v on the coil, so the only other point of failure is the connection to the amp from the coil. You can unplug the amp, and try shorting the -ve side of the coil to ground with a wire and see if you get a spark. It wont be as good as the one from the amp as you dont have the required capacitance for a full voltage, but you should still get something HT wise.

Just as a general clue as to whats going on- the ECU needs a good trigger pulse from the negative side of the coil as its switched to run the fuel pump. So your test with a screwdriver should also fire the pump for a couple of seconds.

Edited by blitzracing on Wednesday 14th February 13:40

Is it possible that placing a magnet close to the distributor pick-up coil could have an adverse affect?
Could prodding with a screwdriver at the pick-up coil possibly damage something?

Just a thought, perhaps the OP will misunderstand something here and make a bigger mess of things

[blitzracing]

Ive done this, and it works as long as you don't physically damage anything by being a gorilla. All you are doing is producing enough flux change manually for the trigger head to produce a small voltage and fire the amp, there is no risk over overloading anything.

[Penelope Stopit]

I must be imagining that placing a magnet close to another magnet with a coil and possibly metal could affect anything

Ignore me, I have no idea what I am thinking about

[Boosted LS1]

OP, which type of dizzy have you got? If it's an early type with 8 ferrite rods embedded in a plastic disc then I've had the exact same fault.