Rough idle when warm Petrol 2.0l 1999

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Tomthehat
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Rough idle when warm Petrol 2.0l 1999

Post by Tomthehat » Sat Aug 24, 2019 11:36 pm

Hello fello bongonaughts! This may have been covered before so please let me know otherwise. I’ve a petrol 2.0l 1999 bongo autotop which has over the last few months been running a little rough, and now will stall on low revs when warm. I have replaced the dizzy cap, rotor arm, spark plugs and ht leads. Ran really well from startup this morning after changing rotor arm but again when warmed up slowing or at idle, revs will become erratic with engine struggling to run and eventually stalling. I’ve tried taking the fuel cap off, this makes no difference. It’s like the engine is fine when cold but becomes worse when warm. Any ideas/thoughts on this would be much appreciated.
mixers123
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Re: Rough idle when warm Petrol 2.0l 1999

Post by mixers123 » Mon Aug 26, 2019 8:35 pm

Hi
Mine done the same , changed everything problem still there.
Found yesterday that pumping the foot brake caused idle to drop to the point of almost cutting out.
Suspected brake servo/booster fault , if you find the same please let me know.
Bongolia
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Re: Rough idle when warm Petrol 2.0l 1999

Post by Bongolia » Mon Aug 26, 2019 10:33 pm

It is possible you have a servo problem but less likely than an air leak. Check all the vacuum pipes and the large duct at the back of the plenum look for splits especially where the smal vacuum pipe meet the large duct. Replace any dodgy ones.if they all look ok have a searh for idle speed control valve. I did a write up on procedures but I cannot find it. Someone may be able to provide you with the link
Ian
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Re: Rough idle when warm Petrol 2.0l 1999

Post by Ian » Tue Aug 27, 2019 7:58 am

Here's the original discussion: viewtopic.php?f=3&t=73643
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Flanners
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Re: Rough idle when warm Petrol 2.0l 1999

Post by Flanners » Tue Aug 27, 2019 8:32 am

From my own experience and looking round this Forum the 2.0 in general is prone to this issue; as it seems are other Mazda's of this era.
2002 2.0 Aero with Outback Conversion and Roof Top Tent
Tomthehat
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Re: Rough idle when warm Petrol 2.0l 1999

Post by Tomthehat » Fri Aug 30, 2019 2:35 pm

I think I might have found the problem. On closer inspection I could hear a arcing noice/spark and found it was coming within the internal coil pack on the distributor. I had previously replaced the spark plugs dizzy cap and rotor arm and leads as one HT lead was very brittle and just snapped. I’m thinking that as the resistance was bad on one lead this caused the coil pack to arc perhaps? Anyway I changed the leads and the problem was still there, so I removed the dizzy cap and rotor arm and the cover/seal after the rotor arm, cleaned where I could get in with a toothbrush and contact cleaner re assembled and it’s much better now, it still arch’s but less often so now will hold revs at 800rpm and doesn’t cut out at traffic lights! I’d like to try and find the part that covers the coil pack as it had a hairline crack and seals were a bit ropey. Unfortunately my jpeg of this is too large but I’ll try uploading after I’ve compressed it.

Thank for all the reply’s
Tomthehat
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Re: Rough idle when warm Petrol 2.0l 1999

Post by Tomthehat » Tue Sep 03, 2019 8:14 pm

Just an update on this, I’m still unable to run on lpg without it cutting out on idle, I need to sort the ignition side out. I’m thinking a new coil pack, can these be purchased separately rather than buying a new distributor?
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