chevyman1980

ok here it goes. I am a mechanic bye trade,but this one is driven me nuts. ill start with it has 2 codes in the ecm 1 for bad cts or circuit,and the other for air temp sensor or circuit. both have 5v and i replaced the cts codes still wont clear. my problem is weak pulse to the injectors. if i disconnect the wire off injector it has good strong ground pulse,when i test it with it hooked up to the injector its very weak and not firen my injectors. and for whatever god for saken reason the wireing schematic i have shows that the ignition coils hot,and the injectors are on the same circuit,but if i run a continuity test it dont have continuity... so i wired the damm 2 together and now bye god its got continuity. not shure whats goin on here,but its driven me nuts. it was at one point and time before i adjusted the tps when i pulled it in gear hit throttle and let off it would hit a few sec then die. but since i adjusted it it wont even do that. it does run off either. aint got much hair left to pull out at this point. hope yall can help. i dont think its the ecm because it has strong ground output when not hooked to injector,but i may be wrong. thanks for youre help.

DennisMik

iTrader: (2)

The fuel injector 12 volts and the ignition coil 12 volts does not come from the same source (other than the battery). You evidently don't have a Nissan wiring diagram. Get one here: http://boredmder.com/FSMs/Nissan/Maxima/1995/

Fuel injectors are in section EC pages 189 & 207. The ignition coils are also in section EC, pages 118 & 119.

The 12 volts for the fuel injectors comes from fuse # 58 and is hot all the time, not switched.

The 12 volts for the ignition coils comes from fuse # D, which then has to go through a set of contacts in the ignition switch. If the ignition coils had 12 volts all the time like the fuel injectors, the battery would be drained overnight.

Besides not fully understand what your problem is, I am curious how and with what type of tester you are using to check the fuel injector trigger pulses.

chevyman1980

yep shure enough never again will i ever go bye a damm haynes manual.. i spent 2 weeks tryin to figure why the injectors had 12v all the time and the coils was hot with ignition thanks to haynes. i was testin the pulse with a continuity tester and it lit up bright when turnin over,then when i hooked it up to the injector it got real dim. but i think i got it narrowed down i started smellin fuel bad so i decided to pull the upper intake and check the back injectors,and 3,and 5 is sprayin really good,but nothing on 1,2,4,or 6. headn out to work on that in a few. thanks a million for the right wireing diagram. shure helped alot. ill let ya'll know what i come up with. thinkin i got a bad injecor again and thier new,but that dont mean anything.

JvG

You might need to have your injectors cleaned and rebuilt.

I had mine done. Cost about 100 bucks.
You have the upper intake manifold off now.

These injectors have a nasty habit of leaking from a failed seal.
If this happens the injectors will need to be removed.

Save your self some grief. Have the injectors serviced right now.

If you dont, you might need to remove the uim a second time.

chevyman1980

ok update here... it turns out that for some reason the ground pulse from ecm is stronger with wire unhooked from injector then it is with it hooked up.. i pulled the upper intake plentium off and i had a injector leakin that robbed all the pressure off the other injectors,but i still have the issue that i posted (not enough fuel to wett the plugs). just wanted to update ya'll with the pulse issue and hope this mabey helps someone else out in the future. also the wireing diagrams that is in the first reply on this are the right and factory service manual. its the complete service manual.

CS_AR

+1 for this. Injector service a mid-life maintenance item that will need to be done eventually. We see failing injector, o-rings, and broken pintle cape causing more problems as our cars age.