piston Posted January 3, 2007 Share Posted January 3, 2007 i finally got around putting some fuel into my lt1 swap z and wired up the alternator and tach and only two pistons are working? how is this? i havent got around into checking everything out but maybe someone can get me some head start on what it can be. only pistons 2,5 and 8 are working but the car fires up and starts. this is weired because first, only 2 and 8 was working and the engine had a hard time starting. after half way into typing this thread, number 5 works and hour later. i didnt do anything and piston 5 fires up out of nowhere. and im still trying to figure out what the deal is. the exhaust runners for 2,5 and 8 are hot but the rest is cool. could it be the opti spark? whats the chances of the rest of the injectors failing? bad wires? but i have spark on the wires. ( screw driver inside wire into plug wire trick) my plug wires are hooked up correctly. it cant be the plugs, i got fuel pressure, got oil pressure and it everything seems to be good. it just doesnt make any since to have the engine running and only runners 2,5 and 8 are hot. the engine ran for more than a minute already and only operated by 3 piston! can someone explain this in advance since it doesnt make much sense to me. i checked the wires and they do have spark. man, im not even mad at this problem instead i have the biggest smile on the face of earth just hearing the engine fired up for the first time. it sound so sick when i rev it, but still hesitates cause only 3 pistons are firing. i know the smile will go away when i get stuck and cant find what the prob is, but i look forward to you hybird experts to pitch in your thoughts. thanks.. Quote Link to comment Share on other sites More sharing options...
gexgexgexgex Posted January 3, 2007 Share Posted January 3, 2007 sounds to me like your injectors are not all firing. sometimes if a motor sits for a while the injectors get clogged or stuck or something. you can test to see if they are opening, by giving them power from like a 9 volt battery. if you hear a clicking sound they are good, if not they are clogged or stuck. two ways to fix a bad injector that i have found, first, a good tap with a hammer-be very careful, second, soak the injector in simple green over night. hopefully this help you. also i would not say opti b/c you have spark at all the plugs Quote Link to comment Share on other sites More sharing options...
Bartman Posted January 3, 2007 Share Posted January 3, 2007 I agree that it sounds like injector problems. You can try the tricks that gexgexgexgex suggested to see if you can get them working, but you may need to invest in a new set. If you're going to be doing any upgrades you should think about getting higher rated injectors while you're at it. Quote Link to comment Share on other sites More sharing options...
ULISES Posted January 3, 2007 Share Posted January 3, 2007 Mike had a similar problem when starting my LS2,Only one bank of the coils were firering.It was'nt running on all 8 cyl.It had something to do with wiring. Hopefully he can chime in. Quote Link to comment Share on other sites More sharing options...
piston Posted January 3, 2007 Author Share Posted January 3, 2007 for now, im going to try the tapping method and some lucas fuel injector cleaners. if it doesnt work, then ill take em off and soak em if it doesnt work either, ill get a new set. im trying to avoid getting a new set right now since im running broke. still need to install the tranny mount and short/balance the shaft. im sure its not the wiring since they all share the same pink wire and at least one injector works on each side. Quote Link to comment Share on other sites More sharing options...
Paz8 Posted January 3, 2007 Share Posted January 3, 2007 What makes you say it "can't be the spark plugs", on the cyl. not firing are the plugs dry or wet? If the plugs are the wrong heat range (cold) they will foul easy. Quote Link to comment Share on other sites More sharing options...
piston Posted January 3, 2007 Author Share Posted January 3, 2007 i was thinking it cant be the plugs because it sat for a while and #5 fires later, the #2-8 fired first, im sure its not the plugs. the plugs are ac delco oem plugs. like everyone says, i agree it might be the injectors cause i pulled #3 plug and it was dry. but who knows, ill look into it today after work and keep it updated. Quote Link to comment Share on other sites More sharing options...
80LS1T Posted January 4, 2007 Share Posted January 4, 2007 What year LT1 are you working on? Here is a 1995 LT1(camaro z28) wiring diagram for the injectors... What kind of harness are you using? Stock but modified or a Painless? Who did the wiring if its been modified? Also remember that a spark plug under compression in a cylinder is a lot harder to fire than one outside of a cylinder so you could still have a spark issue. Just by testing for spark with a screw driver doesn't always mean a good strong spark. It does sound more like a clogged injector issue. Did you clean the tank in your car with anything(aka, did any junk from the tank get caught up in rail and maybe clog some injectors?). I can't believe that you can rev it up on 3 cylinders, I would have thought that it would have died? Do you have a OBD code reader? If its running like you say it is it will probably set a misfire code for the cylinders that you say aren't firing. Guy Quote Link to comment Share on other sites More sharing options...
rdsk8ter Posted January 4, 2007 Share Posted January 4, 2007 i dont know if you guys know this trick but you can ohm out your injectors to see if they are good the bad ones will be way off the chart compared to the others +or- just a friendly note Quote Link to comment Share on other sites More sharing options...
80LS1T Posted January 4, 2007 Share Posted January 4, 2007 Yeah but that wont tell you if its clogged. Just as another note they should be in the 10-14ohm range. All mine are around 13 ohms. Guy Quote Link to comment Share on other sites More sharing options...
rdsk8ter Posted January 4, 2007 Share Posted January 4, 2007 good point didnt think of that yeah the only reason i know that is i had 4 bad ones right off the shelve can you belive that crap Quote Link to comment Share on other sites More sharing options...
piston Posted January 4, 2007 Author Share Posted January 4, 2007 well, i found out my problem. i dont know how it could of happen but the rest of the injectors that wasnt working had no ignition hot running to them. i did the wiring myself and hooked them all up into one and ran it to a 7.5amp fuse to the fuse block. it all should of work, but when i hooked up ignition hot (seprate wires) to the the positive injector pink wire on each of the injectors that didnt work, the engine fired right up. awsome sound! i guess thats something simple and ill be redoing the wiring again. heres a quick pic... Quote Link to comment Share on other sites More sharing options...
piston Posted January 4, 2007 Author Share Posted January 4, 2007 its a caprice wiring harness so the pcm is in the front and the rest goes into the firewall into the fuse block under the passenger side dash. ill post up some more pics when i get home.. Quote Link to comment Share on other sites More sharing options...
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