efp0wa Posted October 27, 2010 Share Posted October 27, 2010 Not that it is, but if so? This engine (4g63 sohc carb) isn't running overly smooth; seems like it is misfiring (as though it has a lumpy cam), takes about 4 minutes before I can let the throttle go so it can idle by itself and then when it does it's at about 1100rpm and jumps around a wee bit. It's a bitch to start too, as discussed it has no choke but it shouldnt be this bad. Has good compression compression. I'm wary of the dizzy and coil, I may change the dizzy back to the previous one and see how it goes then. Quote Link to comment Share on other sites More sharing options...
coldturkey Posted October 27, 2010 Share Posted October 27, 2010 It doesn't have to be even 1 tooth out to run bad, get a timing light on that puppy. When I had issues after putting a replacement sohc 4g63 in my l300 it was a combination of timing, idle set too low, and not enough/too much fuel. Start with the timing though, its either right or wrong, then mess around with fuel/idle till you are happy. Does it run worse/better if you rotate the dizzy? Quote Link to comment Share on other sites More sharing options...
efp0wa Posted October 27, 2010 Author Share Posted October 27, 2010 Runs like shit when I rotate dizzy. Just found my timing light. Will check that out 2mrw. Quote Link to comment Share on other sites More sharing options...
CaMpylobacter Posted October 27, 2010 Share Posted October 27, 2010 pop top cambelt cover off make sure timing marks are lined up. if they're not, it doesn't matter where your dizzy's firing, that's got little to do with it. one tooth out can be a cunt for most cars. with a modified cam in there it'll perhaps be a million times worse. Quote Link to comment Share on other sites More sharing options...
efp0wa Posted October 27, 2010 Author Share Posted October 27, 2010 By The way. Thank you cold turkey. So process: Check/Set Timing>Set idle>Set Fuel mixture Quote Link to comment Share on other sites More sharing options...
efp0wa Posted October 27, 2010 Author Share Posted October 27, 2010 pop top cambelt cover offmake sure timing marks are lined up. if they're not, it doesn't matter where your dizzy's firing, that's got little to do with it. one tooth out can be a cunt for most cars. with a modified cam in there it'll perhaps be a million times worse. They are lined up, checked that yesterday. i just keep having this bad feeling they arn't. Oh and it doesnt have a modified cam, i said "as though it have a lumpy cam" Quote Link to comment Share on other sites More sharing options...
KKtrips Posted October 27, 2010 Share Posted October 27, 2010 I would start again with the basics - what are the symptoms? I wouldn't immediately start assuming complex things like cam timing etc.. Quote Link to comment Share on other sites More sharing options...
efp0wa Posted October 27, 2010 Author Share Posted October 27, 2010 -Is hard to start. -Runs rough. -Won't idle until foot has been on gas for about 4 mins after start up. -Fluctuates badly between around 1000-1100rpm. Apart from that it drives ok. Well it did the other day when I drove around the container yard. Quote Link to comment Share on other sites More sharing options...
KKtrips Posted October 27, 2010 Share Posted October 27, 2010 What sort of car is it? When was it last given a decent tuneup/service? Quote Link to comment Share on other sites More sharing options...
efp0wa Posted October 27, 2010 Author Share Posted October 27, 2010 It's a 1990 L300 with a Sohc carb 4g63. Umm just rebuilt the motor... viewtopic.php?f=46&t=24578 Infact you were the last to comment on that thread. Quote Link to comment Share on other sites More sharing options...
KKtrips Posted October 27, 2010 Share Posted October 27, 2010 Just rebuilt the motor - Have you got new spark plugs in it? Is it points or electronic distributor? Is it an auto choke deal? Have you set the tappets? Have you run the engine in? How old is the fuel? Quote Link to comment Share on other sites More sharing options...
efp0wa Posted October 27, 2010 Author Share Posted October 27, 2010 Ok, rebuilt but not really rebuilt. New spark plugs. New leads. Electronic dizzy Auto choke removed Tappets not set yet Used old rings and bearings as they were within spec so didn't see anypoint in replacing; so no real need to run it in. Fuel would be 11 months old. Quote Link to comment Share on other sites More sharing options...
Truenotch Posted October 27, 2010 Share Posted October 27, 2010 How do the dizzys line up on these? If they're a gear drive you may have it one tooth out. Quote Link to comment Share on other sites More sharing options...
efp0wa Posted October 27, 2010 Author Share Posted October 27, 2010 Hrmm good point. They are gear driven. So manually turn motor to TDC, put timing light on and see if it lights up when at TDC. Quote Link to comment Share on other sites More sharing options...
dilusion Posted October 27, 2010 Share Posted October 27, 2010 Have you replaced your fuel filter and given the jets in the carb a bit of compressed air action? I had a few similar symptoms with my car one and this sorted it Quote Link to comment Share on other sites More sharing options...
efp0wa Posted October 27, 2010 Author Share Posted October 27, 2010 Yes did carb blow out action. Hanvt done fuel filter yet, will do 2mrw. Quote Link to comment Share on other sites More sharing options...
dilusion Posted October 27, 2010 Share Posted October 27, 2010 Did it seem to start/idle better for a while once you cleaned the jets out? I did it a couple of times and they re-clogged, seems the fuel filter was so old it had been disintegrating and re-blocking the jets with crap... Quote Link to comment Share on other sites More sharing options...
KKtrips Posted October 27, 2010 Share Posted October 27, 2010 Ok, rebuilt but not really rebuilt.New spark plugs. New leads. Electronic dizzy Auto choke removed Tappets not set yet Used old rings and bearings as they were within spec so didn't see anypoint in replacing; so no real need to run it in. Fuel would be 11 months old. So by rebuilt you mean that you cleaned out the sump and chucked a new head gasket under a rebuilt head? I would do this - Set the tappets and get it running and up to temperature - Set the timing at 8degrees with a timing light. - Set the idle once the car is hot at 750rpm.. - Age of the fuel may be a problem but I doubt replacing it will fix your symptoms You will find it hard to start without a choke - either hook up choke or deal with hard starting - no choice.. Keep the basics in mind.. I have to be honest - it sounds like you have not had a lot of experience with doing this kind of thing before - I applaud the fact that you are giving it a go but I would get yourself a Haynes manual or similar and use it to guide you.. Quote Link to comment Share on other sites More sharing options...
Celica RA45 Posted October 27, 2010 Share Posted October 27, 2010 1st things 1st check no 1 is at tdc then check cam timming and see where disy is at no 1 as well Quote Link to comment Share on other sites More sharing options...
bubblegoose Posted October 27, 2010 Share Posted October 27, 2010 Tappets not set yet do this, all it takes a valve to be open a little bit Quote Link to comment Share on other sites More sharing options...
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