Guest datsundoode78 Posted May 23, 2006 Share Posted May 23, 2006 Hey everyone I recently put a new engine in my 78 280z. The car never had any issues before with not starting. Now when i crank it over i get an ocasional pop off what seems one cyclender only. The firing order is correct, the injector leads were labled on removal and put back on correctly. I cant figure it out. I have spark, i have fuel pressure, im not sure of injector pulse. However i did check the #8 injector harness connector and i have a constand 12v+ on BOTH terminals. I know there is supposed to be 12v+ to ONE side, and then the ECU breaks the ground on the other terminal to make the thing pulse. What are some common things to check? Or does it sound like my ECU has somehow died in the process? ( Yes i unplugged the battery before i got started) HELP! Quote Link to comment Share on other sites More sharing options...
bschiltz Posted May 23, 2006 Share Posted May 23, 2006 A shot in the dark here and forgive me if I'm way off base, but if both terminals are reading a 12v+ then it could be a grounding issue, right? Quote Link to comment Share on other sites More sharing options...
Guest datsundoode78 Posted May 23, 2006 Share Posted May 23, 2006 Yes. but what grounds goes into the ECU and where are they located on the car? Quote Link to comment Share on other sites More sharing options...
bschiltz Posted May 24, 2006 Share Posted May 24, 2006 Sorry, I misread your question. I didn't mean to sound like a jerk. I don't know where the ECU grounds to, but you might try a chiltons manual. They have full electrical diagrams in some of the newer ones. Quote Link to comment Share on other sites More sharing options...
Doug71zt Posted May 25, 2006 Share Posted May 25, 2006 First things first. Check the dizzy shaft timing to make sure that the rotor is phased correctly. If the oil pump shaft was installed out of time, the dizzy won't be firing cylinders at the correct time. I think that this is one of the most common problems on L-series fresh fireups. Doug Quote Link to comment Share on other sites More sharing options...
Guest datsundoode78 Posted May 25, 2006 Share Posted May 25, 2006 If i spray starting fluid into the intake it will start and run until i stop spraying the can. SO i know spark, and timing is close enough to make it run. But only the #3 cyclender is getting fuel. I pull the plug and its wet. If i crank the engine it will pop consistantly on one cyclender ( the 3rd im assuming ) and if i unplug the #3 it wont do anything when its cranking over. What sensors are in charge of sending the signal to the ECU for injectors? The car dosent have a crank position sensor or anything like a newer car. thanks! -e- Quote Link to comment Share on other sites More sharing options...
Mr.INSANE Posted May 25, 2006 Share Posted May 25, 2006 Heres something i personally learned try rotating all your spark plug cables counterclockwise once Quote Link to comment Share on other sites More sharing options...
veritech-z Posted May 25, 2006 Share Posted May 25, 2006 How likely is it that you only have one functional injector? Did you replace the entire engine with the manifolds, injectors, sensors, and all, or did you just take the long block and use all your old accessories? You can dry fire an injector by connecting a 9volt battery to it, and hearing it click (or not if it doesn't work or is stuck), I don't know if you've tried that yet on the ones that aren't doing anything. Have these injectors (whether they were your originals or off this other engine) been sitting for a long enough period of time that they could have developed varnish deposits from the old gas in them and need cleaning? Quote Link to comment Share on other sites More sharing options...
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