I'm brand new to the forum. I'm an engineer and a decent mechanic, but not a master by any means.

I bought a 1955 Chevy with a 1995 LT1 engine from a guy who had a stroke and can no longer remember the car at all let alone anything he did when building it. It's an absolute show car, but it's not a stock Camaro. Most if not all of the emission controls are deleted. When I bought it 4 years ago, it ran very well and has ever since.

I finished the car this summer with some interior details and my dad took it to a few local cruise nights (l store it in his garage). Last weekend, I went to start it and it would not fire up. I checked the fuel pump, the fuses, spark at the plugs, 12V at the injectors, no security light, etc and everything seems to be ok. It fires up with the slightest shot of starting fluid in the intake, then stalls out.

I purchased a Red Devil River ODB1 USB cable to scan for codes but when I tried it today the scan9495 software would not connect with the vehicle. I don't know if there is a specific driver needed so I just downloaded the scan 9495 software again from the Red Devil River site and hoping it will connect next time I try. I'm not sure if there is something disconnected with the port. it has wires coming to it, so I assume it's a communication issue with my laptop.

Besides looking for codes, and if I can't get codes, looking for any advice on next steps.

 

Did you check fuel psi?

 

I ordered a new fuel pressure test gauge and waiting for it to arrive. I can hear the fuel pump turning on but haven’t verified pressure at the fuel rail yet.

I replaced the pump about 6 months ago and had a hell of a time figuring out how to get the pump out of the sealed reservoir. I ended up slicing the top off with a utility knife and epoxying it back together. It’s possible that seam has come apart and I’m assuming that would impact the fuel pressure.

 

When you turn the key to "run" the pump should prime for 2 seconds then shut down. It will not restart until the engine is cranking, and the PCM detects the low resolution cam position signal from the Opti, and receives the "fuel enable" signal from the theft deterrent module.

When the fuel pump primes and stops, you should see at least 40 PSI, and the pressure should drop slowly (if at all) when the pump stops.

 

Finally got over to check the fuel pressure. It's a solid 40psi when it's priming. I still can't read codes. I've tried SCAN 9495 Version 1.0.7 and Version 2.6.2

I don't have a node light so if that's the next step I'll have to get one.

 

Does the setup include the PASS-Key II (VATS) security system, or has it been deleted? If it does, the PCM is looking for the fuel enable signal from that system. There is a bypass available, not related to the resistor bypass. Lack of a fuel enable signal reaching the PCM should set DTC 46.

If you have a problem getting Scan9495 to work, I can get the author to jump in and help out.

 

Yes it has the VATS system enabled. I'll have to look for the non resistor bypass, I've only seen the resistor one.

If my fuel pump primes for 2 seconds and pressure reads 40psi, then when cranking reads about 45psi, doesn't that indicate the PCM is seeing the fuel enable signal from the VATS system.

Help with Scan9495 software would be helpful. It seems like the program is not recognizing the USB communication ports on my laptop. I'm running Windows 10. I'm also looking for a used Actron CP9185.

 

Finally got an Actron scanner and got back over to the garage. There are no stored codes. It also looks like the VATS is already deleted, the security light goes on for a few seconds with the key, then goes off but I can't find any sign of a relay or module in the car.

Here's what's strange. When I check the voltage at the injector connector, it reads 12V with the key on and nothing plugged into the connector. When I plug in a noid light it will NOT illuminate. I confirmed the light is working,

With the noid light plugged in, there is almost no voltage at the connector. Unplug the light and the connector reads 12V again. I can also plug one lead for the light into the pink terminal and ground the other lead and it will light up. I'm at a loss for an explanation. Any help would be appreciated.

 

Are you checking more than one injector? Plugged in the noid light and tried to start the engine?

Key on, engine off 12 volts on the pink wire is correct. The PCM supplies the ground to fire the injector. Connector off the injector, measure the resistance across the two injector pins. Should be in the range of +/- 12-16 ohms.

 

I only checked one injector. Plugged in the noid light and cranked the engine. No light.

 

There are eight independent injector “drivers” in the PCM. Each has it's own wire to an injector to provide the ground. Test multiple injectors for resistance and use the noid light to check the ground portion of the circuit.. The PCM checks each circuit and will set DTC 18 if there is a fault on one of them.

Was the Actron a real scanner model? Or possibly the Actron CP9001 that is just a paper clip in a $30 box and shorts the pins to flash the code on the SES light? The latter only works up to 1993.

 

Thanks Fred. The scanner is a CP9185. I'll try to get over to the garage to check resistance and also check the circuit on a few more injector wires with the noid light. If the resistance is ok and no light on any of the wires, is there anything else I should look at while I'm there?

 

I checked all of the injectors. Most of them are at 12.0 ohms. One was at 11.9 and one was at 12.2.

All of the connectors indicated a circuit with the noid light. The one I checked yesterday must not have had a good connection. The noid light flashed just fine today all the way around.

Again, no codes with the cp9185.

I pulled one plug to confirm there is a spark when cranking.

 

Is it possible to have all 8 injectors stuck? I was going to pull them all out and bench test them next. Does anyone have any better ideas?

 

Outside, fire extinguisher at hand - Pull the rails up with the injectors intact. Put a jar under each injector. Remove coil wire. Have someone crank the engine. Observe injector pulses.