Bluestar

I just put a set of 703 injectors in and and its running really rough. Its smoking bad and wont stay idle unless im on the gas. I got a rebuild kit and rebuilt the injectors and cleaned the holes and fuel rail. I just used a screw driver to remove the gunk from the holds and cleaned the rails with carb cleaner. Why is it doing this? Any help would greatly be appreciated.

motocooney

Did you reset the CPU (computer) following the steps listed in the FSM?

-Hold positive and negative terminals together for 30 seconds
-reconnect battery
-Turn ignition to ON (don't start the engine)
-Turn on lights for 10 seconds
-Turn lights off
-Turn ignition to OFF

Start it up...truck will be running on preset fuel values until it "learns" and adjusts for the new injector flow.

Check for leaks around the injectors both at the fuel rail and at the manifold?

Is the fuel connection at the end of fuel rail connected properly?

If you have to give throttle for it to stay running, my guess would be a leak of some sort. There are only 3 places it could be leaking.

Top or bottom o-rings or the fuel line connection.

Check engine light?

motocooney

Did you re connect ALL vac lines that you disconnected?

Are ALL harness connectors in place and fully connected?

Bluestar

I reconnected everything right back where they came from. I did not reset the cpu but ill give that a try now. and the check engine lights always on for mine because i cut off the cat lol.

Bluestar

I got it to idle after running it for like 15 mins on the gas. Right now it idles and runs but its just like crap and is smoking bad. I reset the cpu like you told me and now I notaced my check engine light is off if that means anything lol. How long does it usually take to smooth out if theres nothing wrong?

Bluestar

I checked them all for leaks one last time and when I twisted the 6th one it was leaking a little. I took it out and the oring was damaged wheil reinstalling. Hooken it all back up but still runs the same. I decided to unplug the wire harness from each injector one at a time. each one that I unplugghed i heard the engine bog down except for the 5th one there was no change in idle. Could this mean that this one injector is bad? Would I be able to put one oem injector in the place of it along with the other 5 703s or to test it? Or would I have to replace it with another 703? Anyone know?

motocooney

That could mean the #5 injector is bad. While it's running grab a long screwdriver or anything else you can put to your ear and to the injectors. They should all be clicking loudly. It will be obvious is one of them is not.

The engine light is off because you reset the CPU. It will come back as soon as the the computer checks and rechecks for cat efficiency a few times.

If you determine that the #5 injector is bad, I would just run to the junkyard and grab another one. Autozone sells the O-ring pack which is really all you NEED to "rebuild" them. It's $2.99

I would not put a stock injector in with 5 "703s".

motocooney

You could throw a stocker in to just test it but don't leave it.

engnman

Had same problem with mine after 703 change.Tested each with a 6 volt battery and # 6 was bad,no clicking sound,replaced it and ran great!

Bluestar

After alot of trial and error I found out that #5 and #2 were bad so I just have the stock ones in its place for the time being. Thank you everyone for the advise.

contrldsub

dont do that for very long, its going to cause a lean condition and you could do some real damage.

notop46

X3^

Your ECU will end up tuning the fuel flow based on the average of 4 "rich" injectors (the 703s) and 2 "lean" injectors (the stock ones). Go find 2 more good 703s before you melt a piston.

Normajean410

What year neon do u get the 703"s out of?

Bluestar

I bought the injectors from a guy online, and dont worry he said hes sending me 2 new ones so I wont have these in for very long.