1999 V8 starting question
Discussion
Gents (and ladies) I will attempt to be brief and detailed here, but I hope to learn from the collected wisdom.
My 99 4.0 Chimaera was left unattended for a period of 8 weeks recently, longer than I had planned to leave it. Last weekend I restarted the car with a jump from the Lexus and it fired up first turn.
A good drive later and I switched it off to open the garage doors. When I restarted it fired as I released the key, after a few seconds of the starter motor cranking over. I thought it wasn't going to start, released the key and that's when it started. This has never happened before.
It seems the the battery had died as it wasn't holding charge, so today I went to get the car out of the garage to fit a brand new battery. A friend came over to jump start it (using his Interceptor no less) and despite the immobiliser deactivating, the fuel pump audibly working and a strong spin from the starter motor it just wouldn't fire up.
Added 5 litres of fuel (just in case, as it was low) and still nothing. So, everything seems in order...the battery was good enough to turn the engine over and new plugs and leads were fitted by Fernhurst as part of a full service in mid-December last year too.
As the car last started as I released the key I'm thinking ignition switch perhaps? Any thoughts or tips guys?
Many thanks.
A saddened Garlick
My 99 4.0 Chimaera was left unattended for a period of 8 weeks recently, longer than I had planned to leave it. Last weekend I restarted the car with a jump from the Lexus and it fired up first turn.
A good drive later and I switched it off to open the garage doors. When I restarted it fired as I released the key, after a few seconds of the starter motor cranking over. I thought it wasn't going to start, released the key and that's when it started. This has never happened before.
It seems the the battery had died as it wasn't holding charge, so today I went to get the car out of the garage to fit a brand new battery. A friend came over to jump start it (using his Interceptor no less) and despite the immobiliser deactivating, the fuel pump audibly working and a strong spin from the starter motor it just wouldn't fire up.
Added 5 litres of fuel (just in case, as it was low) and still nothing. So, everything seems in order...the battery was good enough to turn the engine over and new plugs and leads were fitted by Fernhurst as part of a full service in mid-December last year too.
As the car last started as I released the key I'm thinking ignition switch perhaps? Any thoughts or tips guys?
Many thanks.
A saddened Garlick
Thanks. So far I have been told ignition solenoid/ switch, so this is an interesting post.
The starter was spinning very strongly this morning, with no sign of battery weakness, but I'm grateful for the advice. Do you think adding the new battery is the way to go then? I can do this as I have the battery here, the only problem being (due to gradient) I won't be able to get the car back in the garage if I roll it out to fit and it does not restart after fitting.
Might have to leave this to the weekend.
Oh and.......
The starter was spinning very strongly this morning, with no sign of battery weakness, but I'm grateful for the advice. Do you think adding the new battery is the way to go then? I can do this as I have the battery here, the only problem being (due to gradient) I won't be able to get the car back in the garage if I roll it out to fit and it does not restart after fitting.
Might have to leave this to the weekend.
Oh and.......
spend said:
otherwise consider the common ign amp failure signs (they do all sorts of marginal hot/cold weirdos when they are on teh way out)
Tell me more....in layman's terms 
Garlick said:
That sounds plausible. This thread now reads oddly as some posts have been removed (not sure why?) but hopefully you get the idea.
Any ideas how I reset/ test this?
Thanks for the reply.
Try disconnecting the battery earth for 5 secs , then reconnecting it and immediately pressing the alarm plipper. This will reset the alarm. It can get its knickers in a twist when the battery goes flat.Any ideas how I reset/ test this?
Thanks for the reply.
I think its unlikely to be the problem but worth a go to eliminate it
It could also be the ignition/fuel pump relays playing up ? I had a problem a while back where It would start fine, but having driven 2 miles to the petrol station would then not fire up after filling up. Changed both the silver relays , problem seems to be solved (well not seen it in the month since changing them so I hope it is anyway). Certainly be worth pulling the relays , cleaning the contacts then stick back in again - swap them over at the same time too as that sometimes helps.
Both the above are free (as long as you dont buy new relays) and only take a few secs to do.
Garlick said:
spend said:
otherwise consider the common ign amp failure signs (they do all sorts of marginal hot/cold weirdos when they are on teh way out)
Tell me more....in layman's terms Sounds similar to a problem I am having when starting from cold.
The battery is OK (I think) as it's on a conditioner and always topped up.
Turn key to position II and the fuel pump whirrs into life.
Turn key to position III and it either starts almost instantly - about half a second
OR it just will not seem to catch and turnover.
The starter motor sounds fine and repeated attempts after an initial failure usually keep the motor going but again it will not catch.
I can normally coax it into life with a bit of accelerator pedal but you have to be careful as there is a risk of flooding.
The battery is OK (I think) as it's on a conditioner and always topped up.
Turn key to position II and the fuel pump whirrs into life.
Turn key to position III and it either starts almost instantly - about half a second
OR it just will not seem to catch and turnover.
The starter motor sounds fine and repeated attempts after an initial failure usually keep the motor going but again it will not catch.
I can normally coax it into life with a bit of accelerator pedal but you have to be careful as there is a risk of flooding.
Shamelessly copied and pasted.... Does this help at all?
The key switch has an IGN terminal that stays powered in every position except OFF. The ACC powers in the ACC and ON positions, and is OFF during START. The START powers the starter solenoid. The I terminal on the starter bypasses the ballast resistor during starting to increase the spark. The ballast resistor is about 2 - 4 ohms and reduces the total current to the coil to prevent overheating. During startup, the battery voltage can drop very low, and the coil may not even produce spark without the starter's bypass terminal. The running engine will measure about 4 to 7 volts on the coil + terminal. This is normal due to the resistor. The distributor's function is to position the rotor somewhere in the middle of the cap terminal during cylinder sparking. When things are right, the rotor moves in position, then the spark jumps the gap as the points open.
A bad or missing resistor bypass line can do it. Put a test light on the + side and watch it during starts. If the light all but goes out, use a clip lead to connect straight to the battery for full coil power as a test.
A failing condenser will cause weak spark.
The key switch has an IGN terminal that stays powered in every position except OFF. The ACC powers in the ACC and ON positions, and is OFF during START. The START powers the starter solenoid. The I terminal on the starter bypasses the ballast resistor during starting to increase the spark. The ballast resistor is about 2 - 4 ohms and reduces the total current to the coil to prevent overheating. During startup, the battery voltage can drop very low, and the coil may not even produce spark without the starter's bypass terminal. The running engine will measure about 4 to 7 volts on the coil + terminal. This is normal due to the resistor. The distributor's function is to position the rotor somewhere in the middle of the cap terminal during cylinder sparking. When things are right, the rotor moves in position, then the spark jumps the gap as the points open.
A bad or missing resistor bypass line can do it. Put a test light on the + side and watch it during starts. If the light all but goes out, use a clip lead to connect straight to the battery for full coil power as a test.
A failing condenser will cause weak spark.
Edited by steviejasp on Sunday 5th February 08:29
Blimey that must be from some time ago, with reference to points ! It does have the bit about the ballast feed to the coil- On my V8 loom, its a high resistance wire that feeds the coil when the ignition is on, and from memory it sits at about 9 volts when the coil is grounded. (It will always read 12 volts when the coil is not grounded as not current is being drawn, so there is no voltage drop down wire). Its possible that if the direct battery feed from the solenoid is missing during cranking, the coil only fires once the starter motor has stopped spinning, so the battery voltage lifts back to its normal voltage allowing the coil to spark with its ballasted voltage feed. A simple test meter on the +ve side of the coil during cranking would show a problem if it was anything much below about 9 volts.
Edited by blitzracing on Sunday 5th February 16:52
My suggestion of the ECU temperature sensor was little more than a guess, but if the engine can be coaxed into life using the throttle then it could be that the ECU isn't applying the cold-start enrichment properly. I've never had cause to fiddle with this sensor myself, but I believe my picture below shows its location' just behind the distributor:
If you have the Steve Heath bible, he talks about this sensor on page 87 and gives a table of resistance values at various temperatures. You could probably test it with a meter, by attaching some wires to it and lobbing it into a saucepan of water and heat it up on the hob, along with a thermometer. Or you could just swap it with a known good one and see if the problem disappears!
Here are the temperatures and resistance values:
If you have the Steve Heath bible, he talks about this sensor on page 87 and gives a table of resistance values at various temperatures. You could probably test it with a meter, by attaching some wires to it and lobbing it into a saucepan of water and heat it up on the hob, along with a thermometer. Or you could just swap it with a known good one and see if the problem disappears!
Here are the temperatures and resistance values:
| Temperature (C) | Resistance (Ohms) |
|---|---|
| -10 | 9200 |
| 0 | 5900 |
| +20 | 2500 |
| +40 | 1180 |
| +60 | 600 |
| +80 | 330 |
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