fasteddief23

So I got my fuel pump to function and now my fuel injectors aren't gettin voltage or grounding during key on and start. HELP PLEASE

akylem

year make model... i hope its a honda swapped? stock?

fasteddief23

1998 accord ex coupe f23 engine manual. tell me something good please i'm at my wits ends. I've heard of many problems similar but i can't find an answer

akylem

check all the fuses and try a diffrent ecu also try unpluging it to reset it...

fasteddief23

Ok i'll double check fuses. ecu is kind of an expensive guess. I'll try the unplugging thing. Do you know where the ecu grounds are?

GhostAccord

The injector grounds are as follows;
A1 = Injector #4
A2 = Injector #3
A3 = Injector #2
A4 = Injector #1

The ECU grounds are;
A9 = LG1, Logic Ground for ECU control circuit
A10 = PG1, Power Ground for ECU power circuit (Main Relay Ground)
A22 = LG2, Logic Ground for ECU control circuit
A23 = PG2, Power Ground for ECU power circuit

Was/is your check engine light on constant? Does it flash for 2 seconds when you first turn your key on and you can hear the fuel pump prime?

fasteddief23

unsure about the c.e.l. I dont think my fuel pump does anything until i'm cranking. the only way i can get that to work is if i directly ground the relay. the ecu is not grounding it like its supposed to. also my injectors had no power when key on or no pulse when cranking. ecu grounds them too. could it be bad grounds to the ecu? where can i find them? I dont quite understand the a#'s = Lg pg. I have a wiring diagram from autozone.com the numbers seem different. thank you.

justinsbg

Do you hear your "main relay" click when you turn the ignition switch to the "on" position? You should hear a click when you turn the switch on and a click 2 seconds later when the "main relay" turns off indicating it turned the fuel pump on to pressurize the system. Its located under the driver's side dash to the left. Sounds like relay troubles. Not only does the "main relay" control the fuel pump and supply power to the injectors, it also is a power source for the ECM. Before you get tied up in ECM testing check the relay. Pull it out and inspect the solder joints for cracking and seperation, and even smell it. Usually they'll have that burnt electronics smell. You can resolder them or buy a main relay. They're fairly inexpensive and sold at about any parts stores.

GhostAccord

If your not getting fuel or spark check your main relay and your battery (+) & (-) connections before worrying about ECU ground.

fasteddief23

way past that point guys. The old relay was faulty. I bench tested it after removal. The new one works. but the ecm isn't doing its job by grounding the relay for the fuel pump. when i jump the ground to the relay the fuel pump powers on. I have spark. But when I tried to start it with the pump jumped...still no turn over. I then checked the injectors and they arent gettin any power with key on...nor pulsing while cranking. yet another ecu ground situation. I just wanna check the ecu grounds and see if they're properly grounded but dont know where they are. could you guys possibly lead me to their location...thanks a ton for your responses. I can't tell you how much i appreciate it

0930_SI

iTrader: (1)

bump for some good info, help this guy

fasteddief23

hey thanks for the acknowledgment haha

slomofo

iTrader: (1)

Because I'm bored.


Grounds are everything with a G before the number. The ones that have a side impact sensor near them are the ones under your seats. The one near the SRS unit is under your center console, everything else is under the dash.

Have fun

fasteddief23

wow that's a lot of grounds. I heard there are some grounds on the head or the thermostat housing but they aren't shown in your pics. would these grounds have anything to do with the grounds going into the ecu?

slomofo

iTrader: (1)

If I posted all the grounds, I'd be posting all night. There's a lot of grounds in the engine bay, a couple on your radiator support, one on your front bumper, one in the trunk, one on the gas tank, one or two on the transmission, one on the thermo housing, one on the intake manifold, one or two on the valve cover, one on a motor mount, etc. , etc. , etc. .

The ones I posted are closest to the ECU and the ones I didn't post which are commonly related to no start problems are the one on the thermostat housing which you should be able to find on your own as well as the one on the transmission, but the transmission ground will usually cause a no crank problem.

justinsbg

I'm road tripping right now and I'm not able to pull up the wiring diagram for your car on my phone. Ill look it up later and get back with you.

artie1234

Hello! I'm not sure I have the same problem...Its a 2.3 accord lx no start cranks only...I have spark , fuel pump works, timming ok, checked main relay works (3 clicks), fuses ok, every time I attempted to start it, I checked the spark plugs, they are wet, smart key ok (blink twice). It may be the grounds I want to check the injectors for voltages....the nex thing is the ecu or the crank sensor to be checked.....I used starting fluid in the intake and nothing happened..engine still cranking...thanks for your help .

fasteddief23

I'm going to test those grounds and a few other things i'll respond later with results. I have a diagram from autozone.com. thanks for all the support guys!

artie1234

I forgot to mention ..its a 98 accord lx

justinsbg

I have to ask you because I need to know these basic things to be able to help you to the best of my abilities. So you've checked fuse 46 (15amp) under the hood, as well as fuse 1 (15amp) fuse 13 (7.5amp) in the dash fuse box? They all feed power to the main relay and ECM via the main relay. To clarify, by reading your post I'm assuming you jumped the green/yellow wire in connector A at the PCM which is the fuel pump relay control ground? The MAIN ground for the ECM that you should be concerned with is G101 which is located on the T-Stat housing. As far as grounds for the injectors, I'm sure you know that each 4 or 6 injectors (I'm assuming you have a 6cyl since it's a coupe) have individual grounds at the ECM. When the relay contacts close, power from fuse 46 flows through the injectors and the ECM pulse grounds each one. Fairly simple circuitry when you study it a bit. The only external body grounds relating to the circuit your're dealing with is G101 & G552. G552 is the ground beside the fuel pump in the trunk. Have you checked connector terminals B1 & B9 both yellow/black wires at the ECM for battery voltage? An awesome trick that you can do to check if the ECM is grounded is take the positive lead of your meter and clamp it to the negative terminal of the battery, take the negative lead and clamp it to a good clean ground in the engine bay. Spin the car over and watch the meter. You shouldn't see more than 0.200-0.250 volts (200-250 millivolts). I know that's a lot of info, but I hope it helps. Let me know if you need more info.

fasteddief23

now your speaking my language haha. You must be the one. I just found out what fuse 46 is because in my owner manual its a different number. I beleive its #6 in the engine compartment in my owner book. ok yes every last thing you said makes perfect sense. fuse #1 & #13 are good. when i say jumped the relay..i mean that i grounded the f/p side just to get it to work.(we thought the f/p was bad). the ecm wasnt grounding it like it should while cranking. but thats a complete different power source than the f/i side. I hope its a blown fuse because I beleive i had power to the injectors before i changed the relay. almost 99% possitive we checked them. I blew the f/p fuse when installing the relay so maybe 46 blew too. i know for a fact the w/g wire (12v for f/i, ecm) had no power to it at all. I gotta get power to that before i can check the black/yellow wires. My diagram says w/g should be hot all the time. I have no idea where the t-stat housing is or the ground. the rear f/p ground is fine and the f/p functions when i jump the ground at the relay. If i have to, i'll leave it permanantly grounded. as for the ecm not grounding it...idk. If the fuse for the f/i, ecm #46 is good then idk what to do. could i run a hot wire off the battery post to the relay completing the circuit? i'd bypass the fuse and that might not be good huh? i'll have more done tomorrow. Hope to god it's the fuse.

fasteddief23

I understand the process of the ecm check but i dont understand what i'm looking for. Can you elaborate a little on the .200-.250 volts. if the meter reads that is the ecu grounded or not? thanks a 1,000,000x oh btw it's the 2.3L 4

fasteddief23

Question..And I hope I don't sound too foolish but would trying to crank the car without an injector plugged in blow the #46 fuse that I have'nt been able to find? I think I know where it is now. Also, the car is'nt at my home so I kind of ask a lot of questions before I can check. Apologies for being "that guy" haha

justinsbg

It's Fuse 46 in the Honda factory wiring diagram. It only feeds power to the injectors via the main relay and the DLC (data link connector). Definitely check that and if you cant find the specific fuse just check all of them! There's not that many, just pull them out and see if they're blown. Cranking the car without an injector plugged up won't blow a fuse. If the meter reads those voltages or less that means the engine is grounded. Keep me posted.

fasteddief23

that was it! that damn elusive 46 fuse which is numbered 6 in my manual. it was blown. It must have blown between putting in the relay and trying to start it w/the f/i unplugged. put the new fuse in, the new relay functioning properly w/ the ecm grounding it. no hard wires. car fired right up like a champ! I can't even express how thankful I am with words. I learned a lot about circuits and things these last few days. Now I can go into my automotive electronics class this fall semester like I know whats up hahaa. Well one thing I did do right was diagnose the bad relay so I feel a bit proud of that...thanks again to all. Best to you and yours.