stagefumer11 Posted September 1, 2004 Share Posted September 1, 2004 long post made short. ive had a problem with my l20et being hard to start and constinly missing. and dieing. Ive. replaced plugs. 2 times and gaped. Swaped AFM over 3 times. Checked all ingnition leads. low resistant. Checked cap. Worn but not resistant. Rotor the same, REplaced the fuel pump. Tonight i came across a injector not working. well i was lead to beleive so. as removing the plug made no diffrence with it running. Repalced it with a spare one. and it was the same. but this lead to it backfireing out my intake. and i know thats not good for the afm. Ive also cleaned the TPs. and adjusted. Striped back the Injector loom and checked the circit. all seemed to be good All injector plug output seems to be constint from .6 ro so volts up. changing with rev diffrence. Well to be honnest i have no idea whats going on. Quote Link to comment Share on other sites More sharing options...
rags Posted September 1, 2004 Share Posted September 1, 2004 Since you don't mention at what RPM this is happening, there are two things I would do. A compression check and swap out the ignition coil. Joe Quote Link to comment Share on other sites More sharing options...
Z-Gad Posted September 1, 2004 Share Posted September 1, 2004 Sounds obvious, but check your plug wires with the firing order. I have seen a few times where 2 wires have been crossed and it will cause those symptoms and a dead cylinder as well.... Regarsd ~mike Quote Link to comment Share on other sites More sharing options...
stagefumer11 Posted September 2, 2004 Author Share Posted September 2, 2004 ah ok sorry, i wasnt detailed enough. it backfired out the intake when it was trying to run. say only 500rpm with me on the gas. didnt sound good. it wouldnt run..... I came out today in the morning after charging the battery, and had it start fine. ok to 20 secconds of cranking for it kick right. but idled fine. took it for a drive as soon as i came on to 6psi of boost it missed badly. 1 cylinder is dropping out. ive changed the plugs still the same. ive ran with no fpr. and still the same. with noe tps. again same. same with the o2 sensor. Firing order is fine. plugs are gapped to .8mm i dont know whats going on. the only thing i can think of is another ecu. as the orginal one had similar problems. but it wouldnt pulse the injectors. then killed the fuel system. Quote Link to comment Share on other sites More sharing options...
80LS1T Posted September 3, 2004 Share Posted September 3, 2004 I have seen plug wires cause backfiring through the intake. How old are the wires? Guy Quote Link to comment Share on other sites More sharing options...
stagefumer11 Posted September 5, 2004 Author Share Posted September 5, 2004 sorry about the delayed reply, i dont have the internet at home atm. but anyway. The plug leads are only 5 months old. and have been tested and seem not to be to restictive. I did have a problem last night with my fuel pump Stepping contoll unit deciding to cook itself. i dont know if it was the over sized Merc v8 fuel pump. :/. so i had to wire in a relay system and leave the Fuel pump unit in for the ecu to get a signal to send power to the Coil pack. "weird" Ive also tryed replacing the FPU. but now ive come across one of the barb fittings on my injector number 5 cylinder has split. so its messy. The only thing i can think of left. is yea reaplace the leads. find somehow a new Dizzy cap and rotor and a ignition module. which over here is A miriacle to find brand new. even seccond hand in a good condition. Unless you new Zealander guys know where i can find a brand new dizzy cap and rotor. Not the "small" style but the larger fully electronic ones. I work at Repco so all sorses have been tryed. and no one on our system does them. Cheers all Quote Link to comment Share on other sites More sharing options...
stagefumer11 Posted September 7, 2004 Author Share Posted September 7, 2004 well i removed all the injectors last night. and removed all the hoses and cleaned them up. and tested the current. new hoses and clamps going on to tonight. hopefully ill get it sorted. Quote Link to comment Share on other sites More sharing options...
stagefumer11 Posted September 7, 2004 Author Share Posted September 7, 2004 ok. well took the old girl to the l20et god around here "2 400hp l20ets for his race boat" ANd he said it could be possibly a burnt vavle. meaning it was mis adjusted when the other mechanicl rebuilt the head. "yay" for me. hope it all goes well Quote Link to comment Share on other sites More sharing options...
2126 Posted September 20, 2004 Share Posted September 20, 2004 Just a little technical nomenclature explaination for assistance in future disscusions. BACKFIRE = out the induction side, AFTERFIRE = out the exhaust. 8) Quote Link to comment Share on other sites More sharing options...
stagefumer11 Posted September 21, 2004 Author Share Posted September 21, 2004 well it has been narrowed down to a faulty Dizzy. It keeps advancing and retarding the timing; eraticly. and killing spark. Seems to be common in the electronic style dizzy. dont know if its fixible tho" who knows" Quote Link to comment Share on other sites More sharing options...
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