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| 1275 Struggles to Start https://ausmini.com/forums/viewtopic.php?f=2&t=102475 |
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| Author: | Mick [ Mon Jan 27, 2025 1:03 pm ] |
| Post subject: | 1275 Struggles to Start |
I'm in a bit of a pickle, and I need some advice. My S is struggling to start. It will strike, and make a quick burst to perhaps 2000 RPM, before it collapses and stops. Today, it will do so perhaps 3 times before it stalls completely. A video of the car struggling to start is in the link: https://photos.app.goo.gl/yNrUcH2mjiucm5Wj7 My engine bay layout is in the image, but is 1275 with twin 1.5 SUs: https://photos.app.goo.gl/8NU8hfpcrr3cjhJu9 To this date I have exchanged every part of - the ignition (cap, rotor, leads, points module, spark plugs and coil) and monitored the supply for consistent 12 volts through start (yes). - I have looked for induction leaks, and found none, including by blocking off the PCV and Booster. - Regardles I pulled the carbs and manifold down, and rebuilt, including manifold takeoffs. The jets are clear, and bowls have the right levels of fuel, and the gaskets are all new. - The dizzy curve is locked, and there is an accuspark blackbox. I have removed the box and connected the dizzy straight to the coil. No change. I even took the opportunity to try out the new stealth mk3, to see if it was the old stealth mk1 that was the problem. - I've drained and replaced the fuel, clearing the lines to ensure a fresh batch. - Compression is great, and it seems to fire on all four cylinders when it does kick. I'm pretty happy ticking along with it, but I'm out of ideas to chase. I'd appreciate ideas, and will happily retest if I need to. cheers Mick |
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| Author: | 1071 S [ Mon Jan 27, 2025 1:09 pm ] |
| Post subject: | Re: 1275 Struggles to Start |
Dashpot oil correct?? Car will run without oil but will be a B^&%$ to start.... Cheers, Ian |
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| Author: | Mick [ Mon Jan 27, 2025 1:59 pm ] |
| Post subject: | Re: 1275 Struggles to Start |
1071 S wrote: Dashpot oil correct?? Car will run without oil but will be a B^&%$ to start.... Cheers, Ian Thank you. I've topped them up yes. Proper SU brand and all this time too ( first time ever) |
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| Author: | Steam [ Mon Jan 27, 2025 3:26 pm ] |
| Post subject: | Re: 1275 Struggles to Start |
Some ideas. Starting and immediately revving to 2000 would suggest severe overfueling or flooding before the carbs runout of useable fuel. Air leaks also cause this phenomonen. I have had severly blocked air filters cause overfueling before stalling. However I must say that it sounds like ignition on you video. Would it be possible to switch in a completely standard points setup to prove / disprove.. Do not assume new parts are not faulty either!!! Also a rather last ditch trick I have used is to put 10 or so mls of fuel in each plug hole then try firing. It may eliminate the igntion. Bset of luck. |
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| Author: | timmy201 [ Mon Jan 27, 2025 4:34 pm ] |
| Post subject: | Re: 1275 Struggles to Start |
Some more things you can double check: Base timing it set correctly Spark plug gaps set - and are the spark plugs fouled? Are the leads on in the right order? What’s the resistance from the inside the distributor cap terminal to the spark plugs end of the lead? Which ohm coil did you fit? |
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| Author: | 68+86auto [ Mon Jan 27, 2025 9:06 pm ] |
| Post subject: | Re: 1275 Struggles to Start |
It seems like an ignition fault to me (I hear a backfire?) although since the carbs have been apart there could now be a combination of faults. You could try disconnect the tacho, faulty ones can cause issues. Since it's a 29d, the cap and rotor will be used unless you've got NOS. Are they definitely good? The ignition system should always be proven to be working correctly before the fuel system is touched. Carbs rarely fail suddenly. Attachment: image_2025-01-27_210617057.png
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| Author: | Oscar [ Tue Jan 28, 2025 10:09 am ] |
| Post subject: | Re: 1275 Struggles to Start |
Yeah I agree. I'd definitely be going through the ignition system Mick. Just watch that highly erratic pulse of the strobe light and match it to the running (or not) of the engine. Do you have another known good dizzy you could throw in to eliminate that as the culprit? Any one will do for the purpose of the exercise. |
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| Author: | Mick [ Tue Feb 04, 2025 5:48 pm ] |
| Post subject: | Re: 1275 Struggles to Start |
Sorry, I've been away the last couple of weeks, but am back again. Yes I'll chase out the ignition system again, but I've exchanged everything so far (excepth the body of the dizzy). It might be time to drop in a 25d I have spare. |
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| Author: | Steam [ Tue Feb 04, 2025 5:55 pm ] |
| Post subject: | Re: 1275 Struggles to Start |
I have just listened to it again and I wonder if it is the firing order or the timing that is out or it is only firing on 2 or 3 cylinders. |
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| Author: | ausdino [ Tue Feb 04, 2025 10:57 pm ] |
| Post subject: | Re: 1275 Struggles to Start |
Fine crack in the distributor cap caught me out once. |
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| Author: | Mick [ Thu Feb 20, 2025 4:27 pm ] |
| Post subject: | Re: 1275 Struggles to Start |
ausdino wrote: Fine crack in the distributor cap caught me out once. The 29D dizzy caps are rare parts these days. I replaced the cap with a "good" used one I had, and then with another two old black LUCAS caps I had floating around, but the problem remained. Same with the rotor button. Good news was I replaced the dizzy with a 25D and the problem disapeared, but I'm going to platy with the module (and also check the advance mechanism beneath) as I think that might be the next stop. |
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| Author: | Steam [ Thu Feb 20, 2025 7:11 pm ] |
| Post subject: | Re: 1275 Struggles to Start |
Does the 25d have points or is it on the same electronic system? |
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| Author: | Mick [ Fri Feb 28, 2025 7:30 am ] |
| Post subject: | Re: 1275 Struggles to Start |
Electronic points. I haven't gotten to the dizzy yet however, work keeps me pretty busy, but its on my mind a lot. |
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| Author: | 68+86auto [ Fri Feb 28, 2025 9:11 am ] |
| Post subject: | Re: 1275 Struggles to Start |
What's the condition of the flexible wire between the advance plate and body? |
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| Author: | Mick [ Fri Feb 28, 2025 10:36 am ] |
| Post subject: | Re: 1275 Struggles to Start |
Ah yes, I did replace that wire, +ve and the -ve as well. It may have been those connections. When I get to the dizzy I'll pull her down anyway, and replace with the new wires included. Maybe the wire strands were fractured. |
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