Guest Anonymous Posted October 13, 2000 Share Posted October 13, 2000 I pick up a 1983 280z turbo to use the parts in my 1970 240z. The turbo has 130k and seems to be missing on 2+ cly and there seems to be good spark. The spark plugs are some "Mighty brand" and 4 of them smell of gas and are wet, also seems to be a large gap used on the plugs.Car will bearly run, kind of chugs. The strange thing is that if I give it gas at an idle in neutral the boost gauge will jump to a steady 7lbs of positive boost and stay there until I let off the gas. Is this normal? Have not done a compression test yet.Car doen't smoke. Could the boost mean that the exhaust is some how plugged? Fuel injectors? Thanks in advance for your help! ZGOO ------------------ ZGOO Quote Link to comment Share on other sites More sharing options...
Drax240z Posted October 13, 2000 Share Posted October 13, 2000 Ok, bud do yourself a favor before you try to figure out everything else. Go buy yourself 6 NGK sparkplugs, the ones meant for that engine. Gap them all to around .035-.045" and start it up. Then see if you have the same problems. This will only cost you a few bucks and it sounds like you need them anyway. As far as 7psi boost goes, that is right were it should be I think. From what you described there I don't see a problem... but maybe I am misunderstanding. The one other thing to do is to check your spark plug wires for resistance. They should all be similar. (long ones will have a higher resistance) If any are suspect, change them all. Also go through your ignition system (coil, cap, wires) and make sure all the connection are perfectly fit and tight. It sounds to me that you have some ignition gremlins, but hopefully this should work them out. Keep us posted. ------------------ "THE STREETS WILL FLOW WITH THE OIL OF THE NON-BELIEVERS" Drax240z 1972 240z - L28TURBO transplant on the way! http://members.xoom.com/r_lewis/datsun.html Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted October 13, 2000 Share Posted October 13, 2000 I will get some new plugs (NGK)and try that, but the boost will jump up to 7 lbs with out any load on the engine and with the dead clys. Is thi normal to show boost with out a load? Thanks ZGOO ------------------ ZGOO Quote Link to comment Share on other sites More sharing options...
randy 77zt Posted October 13, 2000 Share Posted October 13, 2000 another thing to check-pull vacuem lime from fuel pressure regulater off while engine is running-line should be dry inside and fuel should not be coming out. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted October 13, 2000 Share Posted October 13, 2000 No, you shouldn't be able to get any sustained boost with the car sitting still. As a matter of fact, I find it impossible to believe that you could do that if you wanted to. Stick a real pressure gage on there temporarily(?) and I bet you find the stock gage is broken. ------------------ Morgan morgan@z31.com http://carfiche.com http://z31.com Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted October 14, 2000 Share Posted October 14, 2000 morgan you were right! I put a pressure gage on the manifold and it never went to boost pressure when reving it up. I replaced the plugs and did not see much improvement. I did a compression test and the cly were all about 150# (is this good # for this engine?)The vacuum gage that put on the manifold is reading about 12-15 lbs which is low. Then when I rev and hold the revs steady, it drops to 5lbs of vacuum.When pulling the plug wires one at a time when the engine is running 1,3, and 6 cly are running some what good and 2,4,5 are deap no change with wires removed.Former owner said the engine just started getting worse over a few day. Would this mean that some bad gas got in the injectors and pluged them up? How do I test the injectors? And thanks again for your help!!!! ZGOO Quote Link to comment Share on other sites More sharing options...
Drax240z Posted October 14, 2000 Share Posted October 14, 2000 Good call Morgan. Anyway, sorry to hear the plugs didn't help, but at least you can rule them out as a problem now. Did you check the resistance in your spark plug leads? Since 2,4,5 aren't making a difference when you pull the leads off either: A) Those 3 leads are shot or those 3 cylinders aren't getting fuel correctly. Test the leads with an ohm meter. If they check out ok, try removing the electrical connection to the fuel injectors (2,4,5) one at a time and see if THAT makes any difference in how it runs. If no difference, you'll need to pick up some new injectors. (or used ones in good shape) You might also want to run a bottle of injector cleaner through your system. Keep at it and let us know if it works for you! ------------------ "THE STREETS WILL FLOW WITH THE OIL OF THE NON-BELIEVERS" Drax240z 1972 240z - L28TURBO transplant on the way! http://members.xoom.com/r_lewis/datsun.html Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted October 14, 2000 Share Posted October 14, 2000 drax, I even whiched wires between the good and bad cly and that did not help same cly were still dead. ZGOO Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted October 15, 2000 Share Posted October 15, 2000 This is why I don't like injected S30 or S130s! Stupid electronics can't tell you what sensor is broken! Check the resistance of all the injectors, they should be 2-3 ohms or 10-15 ohms depending on what type of injector a 280 uses(I have no idea). It's fairly easy on a 280, swap the injectors around a little and see if that changes which cyclinders are bad. You might try cranking the engine while a friend holds the fuel rail up in the air so you can watch the injectors fire. Wear saftey glasses and don't inhale atomized fuel! Look for a nice cone pattern and more importantly, that all 6 patterns look the same. ------------------ Morgan morgan@z31.com http://carfiche.com http://z31.com Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.