skib Posted April 30, 2009 Share Posted April 30, 2009 Well I finally finished up my L28et swap (81'), but its still running rough and lacking power. Timing at idle reads 10 on the number plate; I tryed to change the timing but got nothing, that screw on the 81 CAS is a PITA , and its prone to some back fire. Im kinda suspecting a dead injector or two since I can pull some of them off and theres no change in the way it runs. still kinda new to having EFI and all that, any suggestions? Quote Link to comment Share on other sites More sharing options...
HowlerMonkey Posted April 30, 2009 Share Posted April 30, 2009 If the injectors sat for a while, you might have to run the car and get it warm a couple of times to unstick gummed up injectors. I just went through this with 4 sets of injectors and all unstuck eventually. One set actually fouled a plug because that cylinder was too lean to fire. Quote Link to comment Share on other sites More sharing options...
skib Posted April 30, 2009 Author Share Posted April 30, 2009 Interesting, they have been sitting for a while and who knows how long since before Iv had them. I wonder if running some injector cleaner that you pour in your tank could rule that out quicker. Quote Link to comment Share on other sites More sharing options...
loy Posted April 30, 2009 Share Posted April 30, 2009 Glad to hear that you got the car running. Have you checked/changed spark plugs? Quote Link to comment Share on other sites More sharing options...
skib Posted April 30, 2009 Author Share Posted April 30, 2009 Glad to hear that you got the car running. Have you checked/changed spark plugs? thanks I havent yet Quote Link to comment Share on other sites More sharing options...
kolonelklink87 Posted April 30, 2009 Share Posted April 30, 2009 perhaps someone will respond explainng that this is a bad idea but I've had previous problems with gummed injectors and have used a carb-cleaner soak to solve the problem... damn that stuff is an awesome solvent. Quote Link to comment Share on other sites More sharing options...
S130Z Posted April 30, 2009 Share Posted April 30, 2009 Go back and check ALL of your grounds. Which EFI system are you using? Quote Link to comment Share on other sites More sharing options...
skib Posted April 30, 2009 Author Share Posted April 30, 2009 Its all stock harness and ECU Quote Link to comment Share on other sites More sharing options...
HowlerMonkey Posted April 30, 2009 Share Posted April 30, 2009 I didn't use any harsh chemicals on mine.........just ran it long enough to get warm, pulled spark plugs to check if the non running cylinders were wet, and used a long screwdriver to listen to the injectors while wiggling terminals. It took a few times getting warm and then shutting it off to let it sit for about 1/2 an hour to unstick them. Making sure the electricity makes the trip should be first. Quote Link to comment Share on other sites More sharing options...
TommyZ Posted May 1, 2009 Share Posted May 1, 2009 sometimes injectors get stuck/clogged. I have a couple of shops here in south FL that cleans/rebuild's fuel injectors for $10 dollars each.. I dont know if you can find such a shop where you live... But I would check the basics first.. if you have'nt changed the spark plugs change them, make sure to gap them...check cap, rotor , fuel pressure... Quote Link to comment Share on other sites More sharing options...
rejracer Posted May 1, 2009 Share Posted May 1, 2009 Tolulene, Xylene and acetone are all great fuel system cleaners. Google "Homebrew octane booster" my favorite mix is even parts gasoline, toluene and xylene. It's not suggested to run that much cleaner through for a long period of time, but for a 3 to 5 gallon mix which will be used in a matter of days, it will be fine. The finial mix is 107 octane if you start with CA 91 fuel. I ran my 83 turbo on it, as well as my 83 NA car on it and both ran great with it in there. ohh and I love this site.... http://www.easyperformance.com/Tech_Info/Octane_Booster_Wizard_Content.html Before you put that in there it's important to drain the tank if it has been sitting a long time. it's a good idea to change your fuel filter as well, before and after. If the fuel system is in good shape already (tank, lines and filter are all clean) I would say you could get by without changing the filter. Quote Link to comment Share on other sites More sharing options...
dexter72 Posted May 1, 2009 Share Posted May 1, 2009 very cool Quote Link to comment Share on other sites More sharing options...
skib Posted May 2, 2009 Author Share Posted May 2, 2009 Ok, so here what I found. All new NGK plugs and wires since they where black and I had the while Im at its with the wires. I installed the new plugs and cranked it over a few times with the wires unplugged and then pulled them all. They all have fuel on them except 3 and 6 which are bone dry. Connecters arnt corroded or anything so Im looking at 2 dead injectors now. Should be able to pick up some spares tomorrow and test that theory for sure. Quote Link to comment Share on other sites More sharing options...
HowlerMonkey Posted May 6, 2009 Share Posted May 6, 2009 I would put two old plugs into the non-firing cylinders and run the car to get some heat into the setup. Just keep it running with your foot on the gas long enough to get it to operating temperature and shut it down. Let it sit for 1/2 hour then restart and shut down so you can check if those plugs are now wet. If they are, put in the two good/new plugs and see if you get all cylinders. Heat does better than most anything else when unsticking injectors. Quote Link to comment Share on other sites More sharing options...
Administrators BRAAP Posted May 6, 2009 Administrators Share Posted May 6, 2009 With the car running and everything plugged in, have you listened to the injectors with a mechanics stethoscope to verify that the offending injectors at electrically/mechanically operating? Listen to each injector at the exact same location, they all should sound the same. A sharp "clicking" sound. If you don't have a mechanics stethoscope, you can use a long screw driver. Tip against the injector, ear on the handle of the screw driver. If no clicking or soft clicking, wiggle the connectors on that injector. Even try swapping connectors for known running injector. (the stock EFI is not timed like spark plugs, they all open and close at the exact same time so no worries of crossing injector wires). Quote Link to comment Share on other sites More sharing options...
skib Posted May 6, 2009 Author Share Posted May 6, 2009 what I ended up doing was replacing the injectors and put on all new injector connectors. Its running pretty strong now, just have to adjust the timing. Quote Link to comment Share on other sites More sharing options...
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