Haven't been here in awhile and need some assistance. This is one of those cases of if it's not broke don't fix it. Now it's broke

Decided I wanted to pull my injectors and have them cleaned, inspected and tested since the cone looked ok but could be better so I thought. Got them back and everything looked good on them. Installed them back in the car and rebuilt the TB's with new gaskets since I had them apart. Started the car up and I think I got an initial prime (been a few months now and just getting back to fixing it) but TB's started leaking like crazy. Corrected all the leaks and now I have no fuel from the injectors at prime or running. So here is what I have done so far:

- I have pressure at the first TB and in between the two TB's (have a gauge on it and get an initial prime pressure of 12 PSI between). Fuel pump was changed a few years ago to the 85 version. Added additional gas so good there. It appears I don't have any issue with getting the fuel there I am assuming.
- Installed a noid light and getting pulses to the injectors when cranking.
- Looked in the shop manual (chart 4A) and it led me to check the voltage coming from the ECM at pin 430. This was below one volt so this pointed me to the module and coil. Don't appear to have any open or short to ground situation. Decided to just change these two out as the car set for many years before I got it running several years ago and they were original. So I now have a new module and coil installed.

Tried to start the car, no initial prime but pressure gauge goes up to 12 psi between TBs and then settles down. I just get a couple drips from the injectors.

Any thoughts or suggestions? Going to take the TB's apart again and pull the injectors just to make sure I have done something there.

Thanks

 

Yes, that seems to the the problem. If everything was working before, start with what you "fixed"

Consistent fuel pressure with only a drip of fuel tells me that you did something to the injectors. Probably not seated correctly.

 

BE CAREFUL on some of the new coils being sold. They can be painted black...and that may make them look good ...but where you NEED to make sure your ground strap UNDER the coils is making a good ground along with the wire that also grounds to the coil housing may need to have the paint removed....just saying.

You are aware that the injectors are not teh EXACT SAME.... and that they are SPECIFIC and can not be switched.

DUB

 

I would also take a look at the injectors.there is a front and back.

 

DUB

So how do I tell the difference? I had them labeled when I shipped them out but no guarantee they were not switched when they came back.

I will check out the grounds. It is a Flamethrower module and coil.

One of these days I just need to bring it to Charlotte and have you fix it!!!!

 

I know that the really small guide pins that are in the injectors are in different 'clocked' positions...from what I can remember....so when they go into the housing...the TWO LARGE pins that your electrical connector to should be positioned correctly so these connectors can actually go on.

DUB

 

look at the numbers on the injector.19160434 is the front .19160435 is the rear.that should be gm numbers

 

EVEN BETTER YET!.

I am not at work where all my info is.

DUB

 

Took them out and they appear to be in the correct orientation based on how the connector pins are sitting in the TB. Didn't see the later post from Terry82 until I called it quits for the night. Tried to read the numbers but hard to see but since I now have them might be able to make a few of them out.

I think they are in right and didn't see anything obvious wrong. Looks like I have plenty of gas at the TBs because it was running out when I pulled them loose.

Any more thoughts? I contacted the guys that cleaned and flow tested them and he said he would check them out again (no charge) to see if something was sticking. Seems strange that both would do it at the same time though. One would work without the other one working correct? I have a couple other injectors from some old TBs but have no idea whether they work or not.

Thanks for your help Terry82 an DUB.

 

Hopefully they are stuck. And if the guy who do whatever to them stands behind his work...hopefully he can figure it out or at least verify that they are good or bad.

Knowing that one of the pins on the injector is for power coming in...and the other is for the ground...you could connect the power lead THEN momentarily connect the ground lead to it. See if you can feel them or hear them click. IF not...tap on the injector to shock it and try again.

I had a 1989 in my shop that had 5 gallons of water in the fuel tank..and the power kept trying to get the engine to run NOT KNOWING that the fuel tank had that much water in it....so...water was in the injectors.

When I got it and cleaned out the fuel system and got fresh fuel to flow through the engine...I still could not get the engine to run until I went out and tapped on the injectors to get them to work again. Once I did that...all was good.

I was always told that the injectors for the Cross-Fire engines could not be cleaned or disassembled...and with the spray pattern being so big...versus that of the Tuned-Port engines....the pintle of the injector really does not get too clogged up and causing a poor fuel spray...and if it does...put 1 quart of unscented mineral spirits in the FULL tank of fuel and that is the the cleaning solution for the injectors.

You could try your other injectors and see what happens. I still live by the rule...the injectors can start going bad at 70,000 miles. And just becasue the car does not have 70K on it...does not mean the injector can still go bad.

DUB

 

I have a variable power supply (with a momentary switch) that I could use to power them with. Any idea what voltage is normally running to them?

If all else fails, I will just send them back and have him check them again. Might as well try the other injectors too. I might at least find out whether they work or not and point me in the right direction if it is a clogged injector.

Thanks

 

Definitely the injectors are stuck. Tried the voltage test above and no click can be heard. Found one of my really bad looking injectors (these actually might be newer than the ones in the car) and can hear an audible click. Decided to put this injector into the car and it worked perfectly, the other one was still stuck. After messing (putting power to it) with the stuck one now it appears to be stuck open as it will just dump fuel straight in. Before nothing came out. I at least now have one that is working.

Decided to grab the other old one and could not hear any click. Keep popping power on and off and finally started to hear something. Installed it in the car but it wasn't working right but was getting some fuel into a small cone. Decided I would take a break and came back in about an hour. Started the car and they are both working correctly now. Appears the gas coming through it unstuck the injector. So now I have both working but they were not the initial set I was working with.

I currently have one of the ones that were cleaned sitting in a little bit of gas to see if it might loosen up any. Looks like I will be sending them back to the guy that cleaned them.

Thanks for everybody's help. It has been great appreciated.

 

It may not be the initial set, but it is the right set. Congrats!

 

I am glad you got the old injectors to work.

AS you found out.... and to answer your question...the injector takes 12 volts.

Below it a tool I have for the injectors. It is made to work on current design injectors...but the last photo shows the pigtail harness that allows me to connect to Cross-Fire engine injectors. I can set the amount of pulses I want when I am checking the fuel injectors on the engines with 8 injectors to make sure they are balanced.









DUB

 

I have the same equipment...Great tool to have for injector testing.

 

You BETCHA!!!. I could not do without it.

DUB