82 CE no fuel from injectors

[Shawnee]

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. It appears I don't have any issue with getting the fuel there.
- 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. 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 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

 

[toobroketoretire]

1982 Injectors Not Firing

Assuming your tank has plenty of gasoline in it the injectors should spray in pulses when you're cranking it. When you turn your key ON the injectors should give a little priming pulse and then the fuel pump will shut off after 2 seconds IF you're not cranking it. Your fuel pump won't turn on unless you have oil pressure so make sure the plugin on the top of the oil pressure sender is securely plugged on. When you crank it does your noid light flash each time the injector is supposed to fire? In pulses? If you have a trickle charger try using it to power the fuel pump by connecting it to the fuel pump's wires and see if it starts. If your '82 has anywhere close to 90,000 miles you'll certainly need a new fuel pump relay (mounted in front of the ECM) or you can use a double-sided piece of 600 grit wet-or-dry sandpaper and drag it between the points to restore them to like-new condition. I keep my old reconditioned relay on top of my battery so I can easily replace it if necessary (I now have my relay and it's harness sitting on my battery).

 

[Shawnee]

Too broke,
Thanks for the reply. The fuel tank has gas as I made sure by adding some additional to it. The car appears to be getting fuel to the TBs as I have installed an in-line gauge between the TBs to verify and have checked the inlet side pressure as well. I am assuming because I have pressure I am getting gas to the TBs. I guess I could remove the inlet line and just let it do its initial prime into a catch can just to verify?

Checking with the noid light, I get consistent flashing (pulse) on both injectors while cranking the engine so it appears electrically the injectors are being told to fire.

I just do not get an initial prime pump through the injectors but the pump appears to be working correctly.

My next step is to pull the injectors out and see if there is anything visibly wrong that I can determine with them or the TB.

 

[toobroketoretire]

It sounds like the inlet screens of the injectors are plugged with debris.

 

[Shawnee]

They are new screens so should be good on that point. Not saying I installed everything correctly so I think I will take the injectors out and see.

 

[Hib Halverson]

You have fuel pressure. You have a noid which flashes during cranking. You have a bit of dripping. Sure sounds to me like there's something faulty with the injectors themselves.

Have you contacted the guy who cleaned and flow tested the injectors, explained your problem and asked his opinion?

 

[Shawnee]

Injector Experts was who cleaned them. He said to send them back to him and he would look at them again at no charge. Looks like might be my next step unless I see something when I take them out.

 

[toobroketoretire]

Injector Experts was who cleaned them. He said to send them back to him and he would look at them again at no charge. Looks like might be my next step unless I see something when I take them out.

Perhaps the guys who cleaned them put little plugs in the injector's fuel inlet holes to protect them during shipping. I have 4 of the 1982 injectors in my garage attic in a coffee can and I seem to recall the inlets are about 1/4" diameter and have a super-fine stainless steel screen. As fine as the screens are I can easily see just some dust plugging them. I suggest pulling them out and inspect them. And while they're out you could turn the key ON and flush any debris out of the towers that the injectors mount in.

 

[dougelam]

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. It appears I don't have any issue with getting the fuel there.
- 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. 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 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

Was it running before you started?

I used to have a fuel injector cleaning machine just like this one,

And found that if they sit around for some time after cleaning they tend to stick shut
Funny thing that both would do that though

12PSI is not enough fuel pressure!
Hibs not going to like this because it deviates from the FSM slightly but if you power up the prime wire for the fuel pump you can watch the fuel pressure and as you watch it slightly pinch the return hose and the pressure should start to raise.
If you see the pressure start to rise you know the pump is ok
My guess is that you wont.

Sent from my SM-T530NU using Tapatalk

 

[Shawnee]

Pulled the TBs apart and they looked good, screens not clogged and the right injector was in the correct TB

Dougelam,
Exactly the same thing he said about them sticking after setting for awhile. They didn't sit but about two weeks at the most and hard to believe like you said that both would do it.

I have tried to get more pressure than 12 between the TBs but my regulator will not adjust it any higher. I might get another 1/2 psi out of it at the most before it shuts it completely off. I have plenty of pressure coming to the first TB as I have a gauge in line and it was leaking like crazy when I first put the TBs back together. I'll do the pinch test just to confirm.

Thanks for all your help everyone.

 

[toobroketoretire]

The recommended pressure is 9-13 psi; 11 psi being the preferred pressure. I can't imagine them sticking but I guess anything is possible. I'm wondering if the ECM is sending a low voltage to them. I would think a very low battery charge MIGHT be the cause. If you have a trickle charger you might try grounding one terminal while briefly tapping the other terminal to see if you hear a little "click".

 

[dougelam]

The recommended pressure is 9-13 psi; 11 psi being the preferred pressure. I can't imagine them sticking but I guess anything is possible. I'm wondering if the ECM is sending a low voltage to them. I would think a very low battery charge MIGHT be the cause. If you have a trickle charger you might try grounding one terminal while briefly tapping the other terminal to see if you hear a little "click".

DON'T DO THIS!!!
If they are still good they won't be

Sent from my SM-N920P using Tapatalk

 

[Shawnee]

The battery charge is good.

NO WAY, I wouldn't even think about doing a test like that on an injector.

 

[toobroketoretire]

The battery charge is good.

NO WAY, I wouldn't even think about doing a test like that on an injector.

I have four spares from a 305" so I'll give it a whirl. It just has a little spring-loaded electromagnet inside and I would think it would "click".

 

[toobroketoretire]

Testing 1982 Injectors

Okay, I tested one of my spare 305" injectors by grounding one terminal and applying 12 volts to the other terminal. I made an audible "CLICK". Then I kept the 12 volts going to it for 15 minutes without burning it up because it still went "CLICK" every time it got 12 volts.

Next I powered my '82's fuel pump with my trickle charger then grounded one terminal while applying 12 volts to the other terminal and it went "WHOOSH" (continuous spray). Then after making it go "CLICK" or "WHOOSH" about 10 times I re-connected the electrical plugin and fired it up. No damage whatsoever.

So, I suggest using your trickle charger to see if your injectors will go "CLICK" and if you are too afraid to do it that's okay with me. I just wanted you to know it DOES work.

 

[Shawnee]

Thanks, I have an couple old injectors that I have no idea whether they work or not. Sounds like I might try and see what happens on them first and then possibly give it a try.

Thanks for doing the testing, makes me feel more comfortable. If anyone knows what voltage they normally see I have a variable power supply I could put to it instead of 12v or more.

 

[kpic]

Shawnee,
This link might be helpful.

1982 Corvette Fuel System

 

[Shawnee]

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.