ok guys, so heres the deal i have a 1991 ef sedan (LX), JDM B16 swap, converted to obd 1 and all. My number 4 injector will not fire at all. I have checked everything possible that i know dizzy, main relay,ecu, injectors,map, tps, etc... i even wired the injectors staright 2 the ECU!. .This all started when main fuel pump had grounded out 1 nite...fixed that and now this freaking happens....it's killin me and just hope some honda genius out there can solve this problem...if u need more details u can even call me 757-377-6541... PLEASE HELP!!!!

 

REPLACE THE ECU AND TRY AGAIN also try and change the plug on the injector it self ive had plugs that cause this

 

man, i have tried all that..still no go...its really gettin the best of me... and im not a noob 2 the game..

 

injector wiring is pretty easy, you have; usually yellow wire (+) and (-) which goes to the ecu.
injector power wires will all join together usually at the end of the harness, along with o2, iacv,and some others.
so, you have a couple of possible causes;

ecu
wiring from ecu to that injector
injector plug
injector
positive side of the wiring to the distribution block.

with engine on disconnect #4 injector and measure for power using the battery as a ground, if you get voltage then the problem is in the (-) circuit, injector or ecu. test - wire for shorts and cuts, you might even have to take the harness apart if nothing else works

 

Ditto the above^^^.

I would check for power, 12V+ at each injector, [does injector #4 have power when ign. switch is in run?] power for injectors is supplied by the injector relay in the PGM-FI Main Relay, if 3 injectors are getting power and injector #4 is not, then the PGM-FI Main Relay is not the problem, the problem must be a connection problem.
If the #4 injector is getting power then it is not getting the ground pulse from the ECU or there is a connection problem between the ECU and the injector.
If you have, "man, i have tried all that" meaning you have swapped out the ECU and the injector then it can only be a connection problem.94

 

culd it be some other wire that has sumthing to du with injector number 4???

 

Great advise is already given for the electrical side, I would TRIPLE check that, secondly.... it takes 8 minutes to pull the rail and switch injectors to a different cylider to see if it is the injector itself.

 

do you mean connecting one side to power and the other to ground to open the injector??

 

well i think i may found i issue i was behinf the intake mani.. and i move some wires around and it started running fine.. so now im thinkin it may be in the tps, iac, or iat circut...Could i be on to sumthing

 

I have had the EXAACT issues with mine. I disconnected the engine harness from the car harness and I had to move it out my driveway so I reconnected them and moved the car only to see that it was driving perfect again.


I was told it could be injector, tps, harness. Hate this sputter ****!!


I would like mmuller to elaborate on the good info he posted

 

well i hope i fig this crap out... i mean i dont have a clue but knowing im bot the only this has happened 2 makes me feel a little better..

 

well fellas i got it...it had 2 be something like a ground cause all i did was piggy back #4 ground off of #3...WORKED PERFECTLY!!! i dunno i guess its a way around everything!

 

?????wait say what????? the grounds to the injectors is supplied by the ECU to energize, [fire] the injectors at the right time, if you connected #4 injector ground to #3 injector then both #3 and #4 injector are firing at the same time and that's not right. 94

 

na i jus conected the ground from #4 to the ground of #3 not the signal

 

lol, please read what was posted.. what color was the wire you jumped?
ill elaborate on the system in a little

 

well my grounds where red and black..

 

If there is a red/black at each injector that would be the 12V+ and it is common to all injectors, [supplied by the injector relay in the PGM-FI Main relay.

If your 91 "ef" is the same as a 91 Integra, as I think it is, the problem is probably at the fuel injector resistor pack, either a connection problem or a blown resistor, if so, by connecting 2 injectors to one resistor you have doubled the load on the resistor and it's a good bet it will eventually blow, leaving you without power to two injectors.
Find the injector resistor pack and test all four outputs, red/black, [black at resistor pack], if no output repair or replace the resistor pack.94

 

....sigh....noobs that don't listen or read....

You can't just jumper injectors to one another. Each is getting a seperate output from the ecu, but a common power source. If your jumping grounds, all your merely doing is firing two injectors at once. That's a good way to kill an injector driver.

Injector wiring is stupid simple....don't start jumping injectors together.

Move the injector to the #3 spot and see if the problem moves with it. I don't recall you saying if your running the setup with saturated or peak and holds, but regardless check the ohm resistance between the two poles of the injector. Peak and holds (resistor box) injectors will be roughly 2.5 ohms, saturated will be 11.5-12ohms (check the book for specifics).

If that isn't the case then run continuity from the injector to the ecu for each injector. Check for voltage on the other side with the key in the on position. If all is well then swap for a known good ecu.

Any engine lights while the car is running?

 

nevermind hes been told 10 times already

 

Nice you helped me save my db2, same problom!! (obd1 92 db2 gsr b17a1 red!)
thanx!!

 

GOOD SHIHT MAN, I JUST FIXED MY (DB2 GSR B17A1) same PROBLOM #4 NO POWER HAS SIGNAL!! THANKS!!!! AND IT ALL BECUASE OF YOU BRO, SO *** THE HATERS LET EM HATE!! WE CREATE!!
(1992 DB2 Acura integra GSR G2 B17A1 MONSTER!)

 

The common wire for each injector is not a ground, its a power, smart guy.