Phil_G Posted August 4, 2004 Share Posted August 4, 2004 Hi, hoping that I may be pointed in the right direction. My 1800 zetec (twin carb) has suddenly started mis-firing / popping / stalling and generally lacking power. I'm going to check plugs and basic air leaks tonite, but noticed that I have a 2.5 cm wide rubber pipe coming from the top of the engine and not connected to anything at the moment. Any thoughts on what this is and where it should go - and would it affect my popping problem? I don't think it is anything to do with cooling system and it's certainly not included in the build manual I have. As you can probably tell I am a very virgin newbie when it comes to engine tinkering. cheers Quote Link to comment Share on other sites More sharing options...
Mat Jackson Posted August 4, 2004 Share Posted August 4, 2004 Does this come from the back right hand corner of the cam cover? If so it is a breather pipe which lets the engine breath. These are often run to a catch tank to catch any oil which may be breathed out, but as far as I know if it is just left to vent to atmosphere it wont cause any damage. 2.5cm sounds very big for one though. Anyone any thoughts? Quote Link to comment Share on other sites More sharing options...
Blatman Posted August 4, 2004 Share Posted August 4, 2004 Check uner the carbs. See if the choke/venturi screws are present and correct... Quote Link to comment Share on other sites More sharing options...
Phil_G Posted August 4, 2004 Author Share Posted August 4, 2004 Thanks. Mat - the rubber pipe is the one you refer to and seems generally harmless. Took a look at the carbs and everything seems to be firmly in place. I did notice two of the cylinders (middle two) seem to be much cooler than the outer 2 - would these be the ones mis-firing. I had a cylinder head melt years ago (on an old suzuki) and I'm hoping this isn't the same thing - damn expensive. Quote Link to comment Share on other sites More sharing options...
stu999 Posted August 4, 2004 Share Posted August 4, 2004 I did notice two of the cylinders (middle two) seem to be much cooler than the outer 2 - would these be the ones mis-firing. Mmm. Sounds like you could have an igniton problem. It is highly likely that you car is fitted with what is known as 'wasted spark' ignition' which fires a pair of spark plugs for each rotation of the crank. The pairs being 1 and 4, 2 and 3. Start the engine, and dribble a few drops of water onto the exhaust manifold tubes for each cylinder. The cylinders that are firing will make the water disappear almost immediately. The ones that aren't will be cool to the touch (if you are brave). If the above mentioned pairs are not firing, it *may* be something simple like a duff spark plug. If one plug breaks down, as a pair of cylinders are connected at the coil (IYSWIM), it can short both cylinders out. Swap 2 and 3 with 1 and 4, and see if the problem swaps. If not, other than checking for general wiring connections, and trying another coil for known good one, the problem may lie at the ECU... Quote Link to comment Share on other sites More sharing options...
Doug D. Posted August 5, 2004 Share Posted August 5, 2004 Definitely check/change plugs and leads zetecs are very prone to problems with both. (use NGK plugs) Quote Link to comment Share on other sites More sharing options...
Phil_G Posted August 6, 2004 Author Share Posted August 6, 2004 Looks like this is narrowed down to the ECU. Any suggestions on a good (i.e. cheap) place to get a new one? On a factory built car is it likely to be a standard Ford unit do you think? cheers Quote Link to comment Share on other sites More sharing options...
Blatman Posted August 6, 2004 Share Posted August 6, 2004 ECU's are pretty reliable. I wouldn't be jumping to that conclusion until you're *very* sure. Have you tested the coil pack and associated electricals? Quote Link to comment Share on other sites More sharing options...
Phil_G Posted August 6, 2004 Author Share Posted August 6, 2004 Thanks for the tip - I haven't checked the other bits. Basically by twisting or tapping the ECU I can get the car to fire "properly", which made me think it is some loose connection in the ECU - does that sound plausible? Quote Link to comment Share on other sites More sharing options...
Blatman Posted August 6, 2004 Share Posted August 6, 2004 Well, if you're sure that's what's happening. However, it could so easily be a loose wire in one of the connections on the multi plug, or maybe even a loose earth somewhere. PLEASE do not consider our theories here to be chapter and verse as far as diagnostics is concerned. It would be very rare indeed if we accurately diagnosed a problem such as this, in such a short space of time without either actually seeing the car, or a lot more description about the problem. That's not to say we've got it wrong, but you seem to have made a bit of a leap of faith based on what's been written so far, and I think there may well be a lot more system checking to do yet! I find it is always best to start with checking the simple (and cheap) things first, before diving in and spending what could amount to well over 500 quid on a new ECU, especially as you're running on carbs.... So, make sure you check ALL of the electricals as you can, including earth points and power feeds. Make sure you conduct resistance checks, rather than just having the bleeper on for continuity checking... Quote Link to comment Share on other sites More sharing options...
Phil_G Posted August 6, 2004 Author Share Posted August 6, 2004 Top advice Blatman! I had another poke around, and unscrewed the ECU unit. It is definitely a loose connection in there, but I've just packed it out with some folded cardboard (part of a Rice Crispie packet to be precise! and re-screwed it up. Now it all seems to be running great. I guess I have probably just delayed spending extra cash (assuming the rice crispies won't hold out indefinitely), but thanks a lot for your help. Quote Link to comment Share on other sites More sharing options...
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