Hi,

I need some help!!! I got a Stock 1991 Civic Hatch D15b1 and after a head gasket replacement it doesn't have injector pulse, at least thats what I can see. I have Fuel pressure to the fuel rail, Spark, the timing seems to be right but no injector pulse, it does start for a second or two with starting fluid. I only hear two clicks inside the car when turning the ignition on, one when it turns on the fuel pump, it primes and then the second click its when it turns it off, there is another thing that I don't see the CEL coming on at all is that a sign?

Does the Main Relay power the injectors?
or where does the injector pulse come from?
How can you test an injector? 12v?
Is there a way to bypass the Main Relay? like to power injectors straight from ecu or something like that.

Any Help, comments, advice will be greatly appreciated.

Thanks a lot.

Dan.

 

is possible to manually ground injectors?

 

i just had the same problem with my turbo z6 crx. look at your ground wire where it bolts to your block . also make sure ur ground straps are good . i tryed to replace my main fuel relay, and my ign switch. it ended up being the ground wire where it comes threw the fire wall got cut wile i did my swap

 

I still need help!! The car does run if you pour gas into the tb!! I checked the ground straps that I saw: valve cover to rad support, tranny to body and thermostat housing ( wire comes from harness) Am I missing any other main ground wire? I pulled the main relay and soldered point look good!!!
Out of frustation I tested the injectors with 12v and they do squirt out gas.

What else could it be? Thanks.

 

Anybody?

 

Im having a similar issue. Got the car for free from someone so not sure of some of the history but everything seems to check out except im getting no pulse to the injector= no fuel. will run with the ole pour gas in trick but wont supply any beyond the injector. im reading about possible grounds and also a resistor box??? where is that located?

 

change your main relay maybe that will fix it
make sure your getting fuel pressure at your fuel filter.

 

you can jump the main relay by putting a wire in the back of the plug of the harness just use a 12v on the main relay harness to your fuel injectors its on the the end of the plug i think yellow and white wire and white and silver i have to look at my car again to tell you for sure.

 

There are many things that could cause no injector pulse. I would assume that in putting the head back on a connector was misplaced or forgotten about. The ecu uses a camshaft position sensor to fire the injectors at the right time. I beleive the CMP sensor is in the distributor on a honda. Normally if this sensor fails, the ecu reverts to 'batch firing' meaning the injectors fire half their fuel loads at each TDC, intake and exhaust. But some vehicles will just not run in this case. It could also be a bad injector relay or main relay.

A fuel injection system uses a type or air metering sensor, an o2 sensor, an ecu, and a camshaft and/or crankshaft position sensor to meter fuel and inject it at the right time. You can eliminate the MAP, and O2, as they will not cause a nostart. Check the cam and crank sensors first. I have also seen coolant temp sensors being hooked up wrong or not hooked up cause no starts.

 

Is the multi ground bolted to the thermostat housing its the grounds for the ecu???

 

I don't want to hijack this thread but it sounds like we have the same problem potentially.

I am getting plenty of fuel to the throttle body just no pulse at the injector? Cam position sensor does make sense how can I check that? All my grounds appear to be fine... Idk if it changes anything but I was Just told that the timing belt was just replaced... doesn't sound like the timing is off when its running it'll idle good and quiet

Thx aaron

 

Well an update on mine: I decided to try the main relay. Jumped the injector wire several times and it actually cranked. Couldnt get it to crank on its own everytime but once itd fire it would continue running. The only problem then is that if you attempt to hit the gas even a lil it dies or bogs instantly. I dont know for sure but im guessing a lean bog? Im wondering if the screens on the injectors are dried up from sitting so long. Is that possible? The car sat for 4 years. Im thinking the other guys car probably sat awhile too and possibly the same thing?

 

Update of the day: checked the coil with a multimeter and the primary resistance was 2x what it is supposed to be.. replaced and car sounded exactly the same no change at all! well got it to run after 3-4 times of putting a lil gas down the throttle body but still tried to die with and throttle at all. In desperation i start wiggling hoses/wires and unplugging crap to see what happens(beside throwing codes) and low and behold i unplug the brown(top) injector and it keeps running Hmmm i think well let me try to apply throttle so i do and damn it revs up great!!!! ok i think lets try cranking it. I shut it off and crank takes a little throttle while spinning over but fires up on its own for the first time in 4-5 years!!!!!!!!! I tell my brother to jump in(in case i need help pushing lol) and off we go. Ill be damn this thing drove great let it run apx an hour between making a stop for air etc and driving around. I get home shut off and recrank it several times all of which with the top injector unplugged (CEL on) but i do have to touch the throttle about 1/4 as i do with my carbuerated race car. So now what??? Why is this the case and what can i do to fix that? I really cant wait to give it a shot tm once its cold!!! Any further things to check or advice is much appreciated at this point for a honda noob like myself.

Hope this or our phone call helps some backfroms2k

Thanks again guys for your input!

 

wow thats what my car is doing too......... has been sitting for 5 years.... pics please of what you did?