2.0l Aircooled - Rough mid range

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javawolf
Posts: 2
Joined: 24 Jul 2006, 20:14
80-90 Mem No: 0
Location: 4731 - Flitwick, Beds

2.0l Aircooled - Rough mid range

Post by javawolf »

This is starting to get anonying :x now. My 2.0l a/c has an intermitent issue that I can't get to the bottom of.

To give the background I have already changed the following to stop this issue; HT leads/Coil/Dizzy Cab and rotor arm. I have also noticed a rotten fuel line so changed the fuel lines and filter. Finally the idle value was loose so that was fixed.

The van starts fine every time, and idles no problems (since the value was sorted). It will run fine (and very nicely) for days.

The Problem is sometimes the midrange gets really lumpy, if I give it some gas then the engine will rev fine and it evens out and if I let it idle again no problem. Although once back in mid range it starts up again. Once to problem occurs it will not go away until I let the engine cool.

Now it only does this from time to time and normally when the engine has been run left for an hour or two and then used again. It also backfired once during while playing up, the first time it has done that.

Still to check is the timing and plugs (they were changed in the summer and have about 1500miles on them).

Any pointers?

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matt
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Joined: 09 Oct 2005, 18:37
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Location: #Derbados

Post by matt »

Check timing, and be sure to check the vac advance is werking
Also check for air leaks, esp at the inlet manifolds
these vibrate loose over the years, Also check all pipe werk
:)

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matt
Posts: 7761
Joined: 09 Oct 2005, 18:37
80-90 Mem No: 397
Location: #Derbados

Post by matt »

Oh, and a location wood help, maybe some one local cud have a tinker
Got a strobe lite here in sunny Derby for example :D
:)

javawolf
Posts: 2
Joined: 24 Jul 2006, 20:14
80-90 Mem No: 0
Location: 4731 - Flitwick, Beds

Post by javawolf »

Thanks for the advice. My location is mid Beds, Flitwick to be precise. I'll add it to my profile.

javawolf
Posts: 2
Joined: 24 Jul 2006, 20:14
80-90 Mem No: 0
Location: 4731 - Flitwick, Beds

Post by javawolf »

Ok, so I hope this time it is sorted. Checked timing, it was way out it idle it was about 16 atdc, adjusted it to 7 atdc as per Haynes (not sure if this is the best setting but it sound much happier at idle now). Advance both vacum and mech are good.

Run much much better but the roughness was still there so decided to check the inlet manifold interconnect pipes which dispite being a bit old were ok. Finally put a socket on the carb -> mainfold nut and they were finger tight. Tightend them up and put everything back and now it seems fine.

I hope this is finally it!

Thanks for your help.

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phade
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Joined: 11 Feb 2007, 13:05
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Location: Kent / South East London

Post by phade »

Also check your vacuum hoses. These play a vital part too.

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