davemar 16 Posted February 4, 2008 Just as I thought everything was fine and ready to get the car finally MOTed it's starts being rubbish again .... I fitted some new spark plugs but I've noticed them getting very black and wet very quickly. Needless to say they become a bit hard to spark like that. I'm assuming overfuelling would cause this, but I've tried adjusting the AFM to lean it out, and check with my Gunson's emission tester and it's not way out. When I start the engine it now really struggles to get going (even after giving the plugs a clean) and even when I press the throttle it doesn't pick up at all.Sometimes it doesn't fire up at all when starting now. I put a timing light on the HT leads and that didn't flash, though trying out a plug on one the leads disconnected from the installed plugs did show a spark albeit a rather weak one. It seems the ignition circuit is still playing up, and I'm not convinced the +ve supply to the coil is weak and can't supply enough current. There's a 0.2v voltage drop between the +ve coil connection and the +ve battery terminal when the ignition key is turned to the position before start-up (i.e. when fuel pump, etc. comes on). If the ignition timing was out could it cause this? Or maybe the wrong plugs? Or could this voltage drop mean that the current is too weak and I'm just not sparking properly and burning all the fuel? Unfortunately I couldn't test things much further as the starter solenoid decided to play up at stopped working. I connected the solenoid directly to the battery via a flying lead, and it did nothing, not even a milliamp passing through. So I removed the starter and tried it again free from the car (sat the motor on the -ve battery terminal and a wire to the solenoid connection) and it did work this time. So that looks like yet another intermittent fault. I wish things would make their mind up whether to work or not, I've had enough of this appearing not to work, then working fine and so on, business! Share this post Link to post Share on other sites
davemar 16 Posted February 8, 2008 I replaced the starter, so the thing at least turns over now. But I'm going mad here!!! I seem to be getting a spark, and the fuel pump is running and there's a voltage pulsing on the injectors, but the ****ing doesn't want to fire up! I went back to the old spark plugs as I reckon the new ones I put in aren't right (not sure what they are, the car is miles away), and it still wouldn't start. The best I got was a slight 'cough' as something fired for a pulse and that was it. I've improved the +ve supply to the ignition circuit giving a more direct connection to the battery, so I don't think it's lacking current now. So I'm really stumped to what causing this? I've tried a few positions of the distributor to adjust the timing, but no improvement there. The TPS and AFM wiring all appear to be fine, I cleaned all the connectors I could access. Has anyone got a clue, as I'm going mad here??!! Share this post Link to post Share on other sites
ORB 227 1 Cars Posted February 8, 2008 earth from the gearbox? Share this post Link to post Share on other sites
welshpug 1,666 Posted February 8, 2008 check the pins of the AFM plug, and the AFM itself. Share this post Link to post Share on other sites
nick 3 Posted February 8, 2008 I would also say AFM problem. I forgot to connect mine once on the 8v and it would just start but wouldn't respond to throttle inputs and was idling really rough. Nick Share this post Link to post Share on other sites
Anthony 1,003 Posted February 8, 2008 Check the condition of the dizzy cap and arm - if these are in a poor state then you can get weak spark and make the car difficult to start Share this post Link to post Share on other sites
Simes 248 2 Cars Posted February 9, 2008 I had a similar problem last year which foxed me and Miles. Car fires up normally with 1/2 second so this was out of the ordinary. Same scenario - spark and fuel were there but no bang, didn't want to catch at all. Changed cap Changed plugs. Still didn't work. Turned it over for about 30 seconds with my foot hard on the floor and eventually it caught. I think it was the AFM playing up. Share this post Link to post Share on other sites
davemar 16 Posted February 10, 2008 The dizzy cap and rotor arm are new, so they should be OK. What I've done is to disconnect all the sensors (AFM, TPS, etc) and check for continuity to the ECU, and everything seemed fine. I removed and refitted all the earth connections and cleaned up all the contacts and conductive surfaces. I also made up some new HT leads as the old one were looking a bit grotty. After all this, it did start up and rev OK and appeared to be fine. As I'm lacking an MOT all I could do was drive around a gravel driveway, so couldn't test the power feel, but it seemed OK. I'm not getting too excited yet, as the last time it was like this it went back to being rubbish the next day. So I'm going to check it over again tomorrow after a couple of days of it getting cold and see if it'll start up and run properly. Hopefully it is fine, I can finally put the damn thing through it's MOT! Share this post Link to post Share on other sites
