Why wont it start!?
Discussion
Hi all,
Wonder if anyone can give an informed opinion of the problem with my dear old '93 4-litre (cat) Chimaera.
Have recently had a new ecu after arcing in the footwell from an ill-secured battery. Also had the electrics tidied-up in the footwell area generally, had 2 new fuel pump relays fitted, new ignition relay and a new 072 battery. The car was fine, fired-up so fast i couldn't believe it! However, the chap that fixed her up for me (Ian Truelove at ITS Sports & Performance Cars - cheers Ian), did warn me that the fuel pump may not last too much longer due to the charge i had put on it following the electrical firework show in the footwell. Also the alternator may have been affected.
A few days later, after spending 2 long days renovating the chassis, i drive the car 35 miles back home to Cheltenham, but just as i pull away from a crossroads, the red lights appear on the dashboard and she cuts out on me. Try to re-start the car and it literally grumbles into life and then eventually croaks it, but there was no noise coming from behind the left shoulder on start up, i.e the fuel pump location. I buy a new bosch fuel pump thinking this makes sense, but the garage that were about to mot test her connected a separate battery to the pump, and said that the pump was ok, but there was no live feed to it!?
I'm no mechanic by any means, but this car has taught me a lot. However i remain one of those that hates electrical problems with a passion! Can anyone give an opinion here? Am wondering if the coil was damaged by the arcing in the footwell & is now suspect, though this is a complete guess
Cheers, Adam
Wonder if anyone can give an informed opinion of the problem with my dear old '93 4-litre (cat) Chimaera.
Have recently had a new ecu after arcing in the footwell from an ill-secured battery. Also had the electrics tidied-up in the footwell area generally, had 2 new fuel pump relays fitted, new ignition relay and a new 072 battery. The car was fine, fired-up so fast i couldn't believe it! However, the chap that fixed her up for me (Ian Truelove at ITS Sports & Performance Cars - cheers Ian), did warn me that the fuel pump may not last too much longer due to the charge i had put on it following the electrical firework show in the footwell. Also the alternator may have been affected.
A few days later, after spending 2 long days renovating the chassis, i drive the car 35 miles back home to Cheltenham, but just as i pull away from a crossroads, the red lights appear on the dashboard and she cuts out on me. Try to re-start the car and it literally grumbles into life and then eventually croaks it, but there was no noise coming from behind the left shoulder on start up, i.e the fuel pump location. I buy a new bosch fuel pump thinking this makes sense, but the garage that were about to mot test her connected a separate battery to the pump, and said that the pump was ok, but there was no live feed to it!?
I'm no mechanic by any means, but this car has taught me a lot. However i remain one of those that hates electrical problems with a passion! Can anyone give an opinion here? Am wondering if the coil was damaged by the arcing in the footwell & is now suspect, though this is a complete guess
Cheers, Adam
Hi Adam,
This one caught me out too. My fuel pump stopped priming (couldn't hear on start up) and I looked for volts at the pump and couldn't find any. But clever Phers pointed out that the feed to the pump is only live for a second or so when you key the ignition and then cuts out until the engine starts. Of course, it takes you more than a second to get from the iginition under the car to test the feeds to the pump, so they appear to be dead.
I just had to clean the contacts on the wire ends and on the pump and everything worked again. Others have had to replace the pump relays or fuses.
Not sure whether you have other problems as well but this knowledge will hopefully help your mechanics along.
I wouldn't expect the arcing to have damaged anything other than wiring close to the battery and the battery itself. Coils and alternators are pretty resilient. I can't think how the arcing or shorting into other cables could have affected these but then I'm only a high-voltage electrical engineer !
Cheers,
Matt
This one caught me out too. My fuel pump stopped priming (couldn't hear on start up) and I looked for volts at the pump and couldn't find any. But clever Phers pointed out that the feed to the pump is only live for a second or so when you key the ignition and then cuts out until the engine starts. Of course, it takes you more than a second to get from the iginition under the car to test the feeds to the pump, so they appear to be dead.
I just had to clean the contacts on the wire ends and on the pump and everything worked again. Others have had to replace the pump relays or fuses.
Not sure whether you have other problems as well but this knowledge will hopefully help your mechanics along.
I wouldn't expect the arcing to have damaged anything other than wiring close to the battery and the battery itself. Coils and alternators are pretty resilient. I can't think how the arcing or shorting into other cables could have affected these but then I'm only a high-voltage electrical engineer !
Cheers,
Matt
Edited by taylormj4 on Friday 15th June 11:39
Cheers Matt,
When i spoke with the garage mechanic yesterday evening, although the phone line was a bit distorted (mobile phone speakers? Volume too high?)i recall him saying something along the lines of him trying a separate battery direct to the fuel pump and it was ok, hence his conclusion that the live feed to the pump was not there.
Does this alter your view on what the problem is now Matt or should i still try the pump contacts?
When i spoke with the garage mechanic yesterday evening, although the phone line was a bit distorted (mobile phone speakers? Volume too high?)i recall him saying something along the lines of him trying a separate battery direct to the fuel pump and it was ok, hence his conclusion that the live feed to the pump was not there.
Does this alter your view on what the problem is now Matt or should i still try the pump contacts?
Green Hornet,
Download this PDF as it tells you how to go through your injection system, starting with power checks to the ecu, relay and on to the pump - assuming of course you're happy to wield a voltmeter in anger. If you haven't seen them before, there's a stack of different PDFs on this site including a whole engine overhaul - very useful for torque values and stuff. Don't worry that the menus are in Foreignese, the actual documents are English official Rover books.
Hope this helps you in your quest...
Nick
No Sigs please.
Download this PDF as it tells you how to go through your injection system, starting with power checks to the ecu, relay and on to the pump - assuming of course you're happy to wield a voltmeter in anger. If you haven't seen them before, there's a stack of different PDFs on this site including a whole engine overhaul - very useful for torque values and stuff. Don't worry that the menus are in Foreignese, the actual documents are English official Rover books.
Hope this helps you in your quest...
Nick
No Sigs please.
Edited by Big Al. on Monday 19th May 11:13
I had some outrigger work done on my 93. I had fitted a battery isolator switch to turn the power off on the car as I have a integral garage and my littlun's bedroom is above it. The guy doing the work had turned the car off but not disconnected the battery. When he welded the chassis it still had a feed and blew something! After hot wiring the fuel pump to get the car home I went searching for the problem. I replaced the two relays but no joy. In the loom by the relays was a small black in line fuse holder that looked fine. When I opened it it had completley melted, fuse and all. I replaced it and all was fine.
All,
Thanks very much for the help & thoughts. Have got to the bottom of the problem - it was the 10A fuse in the wiring loom that includes the fuel pump relays. It had blown according to the mechanic that looked at it. However,new fuse in, but when i got the car home after a trouble-free drive, after a few minutes i tried starting the car again, and lo and behold yet again no noise from the fuel pump & hence no start-up. Looked at the fuse again, expecting it to be blown, but it wasn't!? Pulled it out, replaced it, and then the car fired-up! So, the fuse holder or wiring to it is suspect. I guess this loose connection is what led to a surge & hence the fuse blowing in the first place?
Is someone going to trump Mr Heath's 'bible' with a better manual, complete with MASSIVE section dedicated solely to electrical problems!!?
Adam
Thanks very much for the help & thoughts. Have got to the bottom of the problem - it was the 10A fuse in the wiring loom that includes the fuel pump relays. It had blown according to the mechanic that looked at it. However,new fuse in, but when i got the car home after a trouble-free drive, after a few minutes i tried starting the car again, and lo and behold yet again no noise from the fuel pump & hence no start-up. Looked at the fuse again, expecting it to be blown, but it wasn't!? Pulled it out, replaced it, and then the car fired-up! So, the fuse holder or wiring to it is suspect. I guess this loose connection is what led to a surge & hence the fuse blowing in the first place?
Is someone going to trump Mr Heath's 'bible' with a better manual, complete with MASSIVE section dedicated solely to electrical problems!!?
Adam
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