You started this thread 2 months ago. I haven't seen the results of tests that were suggested awhile back:

The easiest test was suggested by tequillaboy: Put the throttle to the floor (Clear Flood Mode) and crank it. Even with no fuel injector pulse (look at the table he posted) the engine should fire on the CSI. If = NO, check the CSI system, because it is not working.

With the key in CRANK, is there +12 Volts on the purple wire at the Cold Start Injector?
> If = NO, have you tested the CSINJ fuse located behind the Driver Information Center? Is it good?
> If = YES: Remove the connector from the CSI. Put your meter on the 2 wires. With the key in CRANK is there 12V on the CSI connector?
> > If = NO, the CSI Thermo Time Switch on the front of the manifold is faulty.
>> If = YES, go to last step.
If the above are all YES, have you applied 12V directly to the CSI while watching your fuel pressure gauge (Pump not running, just static pressure.) and the pressure drops?
> If = NO, the CSI is not flowing fuel.

Two months (and a hurricane). Check these things that take just a few minutes with your meter. (Other than the fuse which is kind of fussy to access because of its location.) You don't need an ALDL cable, software for your laptop, or need to learn how to load, use, and interpret the results. 5 minutes with your volt meter, some jumper wire, and your fuel pressure gauge. Confirm that your CSI system is functional.

 

Thank you ! I don’t have a lot of time lately to work on this car, but your post really helps. I will follow your steps tomorrow. I really think it’s a CSI issue, but I will find out.

I have really been trying to figure this out, and have never done “load, use, and interpret”, so this a a leaning curve for me

 

If you haven't figured it out yet, the CSI system is completely independent of the ECM. You can unplug the ECM, put it on your bench, and the engine should fire on the CSI, but won't run after the key is released, as that turns off the CSI. You can't see anything re the CSI in the data, because there is nothing there for the CSI.

If you politely ask tequillaboy to put up the table for Inj PW vs ECT for your broadcast code, and he does, you might confirm that your system is providing the correct injector fueling for the coolant temperature. But for the first start of the day you also need the CSI.

 

I didn’t have much time today, but I pulled the plug on the CSI, and checked the voltage on the Purple wire while cranking a stone cold engine and it read 9.4 volts ?

 

In my last post I stated I'm getting 9.4 volts to the cold start injector, which should mean that the fuse behind the dash is okay or I wouldn't have any voltage at all. If the voltage is 9.4, i;m guessing thats not enough to fire the CSI ? The way I'm reading the flow chart that IHBD posted, I should either have 12v or Zero volts to continue each step ? This is where I am at.

I also unplugged the CSS, and it made no difference, can I jump the CSS connector with a jumper wire and then check the voltage ? What about applying 12v directly to the purple wire side of the CSI ?

 

Pull it from the manifold and hit it with a 9v battery to see if it shoots fuel everywhere. Or pull it from the manifold and have someone crank to see if it fires.

 

Just a question...... Don't all batteries lower several volts during cranking ????? Remember, this device is only active in crank mode. I have found all the injectors I have dealt with will activate with a 9 volt battery. Keep in mind also the below test voltages are directly on the battery. The car is a 12V system, however, the battery (lowered by cranking) is at that instant the greatest voltage in the car, much less a sub system. You should look for ground on the tan line 832. Make sure ground is present during cranking as well. I pulled my CSI injector and tan registered ground (zero ohms) without the car on so you can just meter tan to ground without cranking anything. From what I see the CSI switch's job (sensor) is to send ground to the injector, So ground is the only signal from the CSI switch to the injector. It does share voltage but the voltage is only used by the switch to heat the sensor for timing out the injector, and when it times out it opens the ground to the tan wire 832. Make sure no one used a bunch of plumbers tape on the CSI switch, I believe it gets ground through the body of the switch. Also make sure the injectors fuel line running to the back drivers side of the fuel rail is not crimped.
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So, from what I can deduct from what I have done is that the 9.4 volts I have going to the purple wire on the CSI is adequate to make it work ?

I guess I will just pull the CSI and see if it actually fires fuel, I would be very surprised if it works considering how badly corroded the 8 primary injectors were when I replaced them.

 

This is from Post #84: Easier than pulling the injector.

 

I’m just trying to be clear with your flow chart you posted earlier. I’m getting 9.4 volts to the purple wire while cranking, should there be at least 12v to purple wire or is 9.4v sufficient ? Because the way I was reading it was either I would have 12v or Zero volts when testing it. So when I got 9.4v I was wondering if that was enough, because I’m getting others saying 9v is enough for the injectors, which make me think the CSI is getting a power signal.

I appreciate the help, and will do the fuel pressure bleed down test when putting power to the CSI when I have time this weekend. Thanks.

 

The FSM troubleshooting chart that Donny put up shows that voltage should be "9.6 Volts or more". In my opinion, 9.4 is close enough. With all this testing, your battery state of charge may be low.

 

I did see that, but it wasn’t posted until after I had asked if 9.4v was okay. The steps you posted showed 12v, so I wanted to verify. Lots of info being thrown my way, which I appreciate, so sometimes I get a little confused and just need to keep things straight in my head.

It’s looking more like my CSI is bad, but I will check it this weekend to confirm. What gets me is a lot of other people on this forum say they have eliminated their CSI with no issue, or that you don’t need a CSI in a warm climate like where I live. So that’s why I had ignored the CSI as a possible culprit.

 

I thought of something easy to try to verify that the engine will start if additional fuel is introduced while cranking. Such as an operational CSI will do.

Use a paperclip to back-probe the blk/pnk (driver side) or blk/lt grn (pass side) wire at any fuel injector to make contact with the terminal inside. Rig a long jumper wire that will reach inside the car. Under conditions that you know it shouldn't start, while cranking, touch the jumper wire to a known ground like the lighter shell. (This will force one bank of injectors wide open). If it starts, you need the additional fuel that the CSI provides.

 

Okay, I have done a few tests on the CSI and it is definitely dead. Now the fun begins at finding a new one, local fuel injection shop says they are non-rebuildable, I see Dino's Corvette offers a rebuild service for them for $175 and put a call into them and waiting for a call back. There is a NOS injector online and they want some $$$ for it, but it looks like its for a 85 model vette, wondering if it would work ? The number on mine is 17080402 and the one I saw is 17080404, other than that they look identical.

 

When you install the new one pay attention and take your time as it is easy to get cocked at a slight angle. the injector can feel like it is and bottomed out but it is not. If I remember correctly my sort of popped in with a small amount of motor oil on the oring. New orings for the injector are available.
You might try spraying it with carb cleaner and hitting it with straight 12 volts from the battery. Maybe it is gummed up .

 

I removed my CSI 20 years ago. I will dig around and see if I still have it.
If you apply 12v to it while you give it s few wacks with something, it may come unstuck, if that is the problem.

 

I sent Jon at Fuel Injector Connection a set of EV1s and he was able to "unstick" (3) of them that flowed absolutely nothing at all. $35 each.

Here's a link to a page where it shows the $35 charge for most injector types. It also has the phone number. Ring him up. $35 beats the heck out of $175.

 

I thought about that, and after a few beers today, I might just give it a few taps with a screwdriver while I hit it with some voltage. I’m just thinking if I do get it to work, how long will it last before I have the same issue again. At least it’s easy to remove, and Dorman actually has the o ring set for the fuel rails which comes with the o rings for the CSI.

 

If you can find your CSI, I will gladly make it worth your time. Thanks.

 

Thanks for that info ! The place here locally said they couldn’t even test it, and wasn’t rebuildable, though I don’t think they have the resources that FIC might have. I’m going to call them right now.