MattyP Posted January 21, 2015 Share Posted January 21, 2015 Hello, I have an xe on carbs in my westfield and have a problem as soon as you hit 5000 rpm the engine starts misfiring badly . Could it be the ecu? I can't find any identifying marks at all on it so was thinking of just replacing it and getting rid of the dizzy as well . What are my options ? What are you guys using ? Any advice greatly recieved Many thanks Matt Quote Link to comment Share on other sites More sharing options...
Kingster Posted January 21, 2015 Share Posted January 21, 2015 Could be a lot of things unfortunately, ranging from fuel starvation to a dodgy coil pack - or plugs, leads, dizzy, ecu etc etc. If you have access to a mate with a similar set up, always helps to swap out known good bits to try and eliminate the culprit. Also try and see if it is just one cylinder (a slightly cooler exhaust manifold is a good tell tale - careful about getting burned though!) Quote Link to comment Share on other sites More sharing options...
tisme Posted January 21, 2015 Share Posted January 21, 2015 A picture of the ecu would help - if it's the standard GM one are there any other feeds to it (like water temp, throttle position, air intake temp, exhaust gas oxygen sensors). I think the C20XE GM ecu should be Motronic M2.5 (with a "hall effect" crank speed and position sensors). The ecu would normally control the fuel injection (but obviously not on DCOE's though normally there would be a throttle position sensor on those as well). So there are a fair few sensors and wiring that could cause the ecu to not like what it's seeing and I've seen other forum feeds (like Migweb) that suggest the ecu can go into "limp mode" to stop the engine over revving if it thinks something is wrong. A Haynes manual for Astra October 1991 to 1996 is invaluable for this engine - and has a fair bit about the wiring / ecu / ignition. I run a DTA ecu (quite old now - the E48) which does all I need for the ignition with a separate map, a proper coil pack and no distributor and just sensors for water, throttle and of course crank speed/position. Where you start problem solving depends on your electrical "debugging" skills - it can get quite expensive to start swapping things out based on guesswork (though sometimes the only way ). A new DTA ecu (S40/S60/S80 depending on what's required) will be about £600 plus from the likes of QED http://qedmotorsport.co.uk/qed-shop/vauxhall-xe-c20xe/engine-management/full-engine-management-ecu-dta-s40/s60/s80. There are other after market ecu's available of course.... Quote Link to comment Share on other sites More sharing options...
SootySport Posted January 22, 2015 Share Posted January 22, 2015 The ECU on your carb car only controls the ignition and is very limited on what it can do and I doubt it is that. Mine is an XE on Dellorto's and Alfpa Webcon ignition and all problems with hesitation/misfiring so far have been down to carb problems or faults on the HT side of the electrics. If all these parts are many years old then I would just change them out, starting with the plugs then the HT leads and dizzy cap. Pay close attention to the wiring on your ignition module/ECU, are the connectors secure? Going to full injection is going to cost the best part of £2k. Removing the Dizzy and using something like an Alpha Webcon is going cost about £800. Quote Link to comment Share on other sites More sharing options...
MattyP Posted January 22, 2015 Author Share Posted January 22, 2015 Thanks to all for replying , I think I would still like to get rid of the dizzy and get a new ignition system as the cars quite old now and I don't know when certain parts have been changed or fitted and being a complete novice on all things technical would need to get someone to fit it , can any one recommend anywhere in Lincolnshire capable of this and that could also give the car a full tune up as it really is in need of some tlc . What actual parts will I require? I've read about mega jolt are they any good as I don't have very deep pockets !! Or am I better saving up and getting the mbe kit from sbd . Sorry to babble on but not understanding it very much makes it difficult to even buy the right bits . Thanks Quote Link to comment Share on other sites More sharing options...
SootySport Posted January 22, 2015 Share Posted January 22, 2015 There's more likely to be some classic car specialists who still fix carb. engine cars around you, seek them out, unfortunately I'm down south so don't know anybody up there. 1 Quote Link to comment Share on other sites More sharing options...
tisme Posted January 22, 2015 Share Posted January 22, 2015 Why not talk to Troy at Northampton Motorsport - they're not a million miles away and have lots of experience with just about every ecu type and Westfields. They do the Omex systems (amongst others) which have a good reputation and an ignition only, distributor-less system could come in under £500 I suspect http://www.northamptonmotorsport.com/default.asp?id=93 or more info here http://omextechnology.co.uk/page74.html You're going to need an ecu, new coil pack, matching plug leads (probably new plugs as well) and any appropriate sensors. The ecu really needs to be "openly" programmable (some like Weber Alpha can only be changed by an approved agent) and although I don't feel that confident enough to change much on my DTA maps, I can and have changed a few of the simpler things to my liking. Quote Link to comment Share on other sites More sharing options...
MattyP Posted January 24, 2015 Author Share Posted January 24, 2015 Thanks guys , will start looking into things and get a shopping list together , Quote Link to comment Share on other sites More sharing options...
Pistol Pete Posted January 29, 2015 Share Posted January 29, 2015 If you go sbd mbe then it is really is just plug and play. Personally i would change the plugs then get it tuned and see if that sorts it. Quote Link to comment Share on other sites More sharing options...
TAFKARM Posted January 29, 2015 Share Posted January 29, 2015 If you're on a budget, I don't think getting NMS to put an OMEX on is the most appropriate solution! Myself and WellyJen (and others?) run MegaSquirt (a derivative of MegaJolt) with fairly good results. There's more likely to be some classic car specialists who still fix carb. engine cars around you, seek them out, unfortunately I'm down south so don't know anybody up there. I'd go for that option first! Quote Link to comment Share on other sites More sharing options...
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