Hey guys,
I've been running my '72 Vega with a carb for about 500 miles. I won't get into the reason why I had to swap the fuel injection on earlier than I expected, but suffice it to say that the car doesn't really run too well when the bolt holding the fuse block together isn't in.

Anyway, at that point I committed myself to getting the fuel injection running. Here's a list of the new parts and my setup.

'72 Vega reworked LT1/T56. Bone stock.
- Painless wiring harness (92-93, PN 60502)
- New ignition module, fuel pump, alternator, starter, battery, plug wires, IAC valve with TPiS IAC passage

My car won't start. At first I thought that I was having a VATS problem so I verified with my Moates AutoProm that VATS was turned off. At that point, I turned the key and the fuel pump turned on! I had to crank the engine a bit to clear out the airlock but I now get a three foot spray of fuel off the Schrader valve.

I pulled #1 plug wire off and grounded it with a new spark plug to my motor mount. My wife verified that it was sparking like crazy. It just cranks. Doesn't even sputter. I nearly ran my battery down trying to get it to run with no luck. I tried at different throttle positions, too.

My setup is about as simple as it gets. No accessories whatsoever. Just the water pump and a low mount alternator. I have a breather in the passenger valve cover and am running the PCV from the middle of the driverside intake to the front of the intake under the throttle body. I have a throttle body bypass IAC passage on the car. Because I have a breather (temporarily) in the passenger valve cover I capped both of the hoses bibs on the passenger side of the throttle body. I have one vacuum hose, from the passenger side of the intake to the fuel pressure regulator.

Anyone have any idea what it could be? I have a new MSD ignition coil I can put on but I'm pretty much stumped. This car was breaking traction in third gear with floating points ignition and a GMPP LT1 intake/Edelbrock 1406. I'm pretty antsy to see what this thing can really do.

Thanks,
Colin

 

I forgot to add that the coolant temp sensor is new, both oxygen sensors are new, and I have block off plates on the back of my intake manifold because I deleted the EGR system.

Thanks for the help,
Colin

 

Squirt fuel in the intake while she cranks it over.

 

I believe you mentioned in another thread that this is a 93 engine. And you mentioned the Moates. If that's the case, you ought to include it in a signature, since there are so many differences on a 93 compared to all other years. Are you using a 93 ECM? Have you tried to flash the codes? Do you even have the ALDL connector and an SES light hooked up?

 

speedygonzales,
I didn't think about trying some starting fluid. I'll give it a shot tonight.

Injuneer,
Yeah, it's a 93 engine. I revised my signature to reflect my setup. I suppose I'll clarify a bit more...

I have a '93 engine with a '93 M29 T56. Running a Painless 60502 LT1 wiring harness. Running TunerPro RT v5 to flash the AutoProm using a small XP-based netbook. The long block is stock. Stock clutch and hyraulics. All of the sensors are stock except for the TPiS IAC passage that requires a later model bolt-in IAC motor. The IAC motor is new, as is the ignition control module, both oxygen sensors, spark plug wires (stock Autozone replacements), recently installed non-platinum spark plugs (non-platinum replacement of the stock LT1 plugs), recently new PCV valve. Also have a new coolant temp sensor installed into the water pump.

Things I haven't changed: fuel injectors, fuel pressure regulator, TPS (removed but recently reinstalled), MAP sensor, Optispark, ignition coil.

So far all I've done is uncheck the "Set" flag for VATS. I AM getting fuel pressure at the fuel rail and I AM getting spark.

Thanks again for the help. I really appreciate it.
Colin

 

Just went through this with another poster. The engine sat for a while and the injectors gunked/crusted over. He bench tested them and they would not move with 12 volts. He sonically cleaned a few and got them working. But in the end he got new injectors.

If you get it to fire with starter fluid, check for injector pulses. If the pulses are there, pull the rails and you know what to do from there.

 

Yeah, this engine hasn't been run with fuel injection for probably 6 or 7 years. I'll try starting fluid. If that works, I know it's probably the injectors. Maybe i'll pick up a set of noid lights. I don't think they're too expensive. I could probably put a stethoscope on the injectors to hear for the solenoids clicking, too.

Luckily, the car is super easy to work on and injectors aren't too expensive. Maybe I'll order a set right now, anyway.

Thanks for the help!
Colin

 

I wouldn't order anything until you do some testing.

 

Just take one out and test it with a 12v battery, you should be able to hear it click. If you cant hear it click, that's your problem. I suggest 30# SVO's or equivalent to go with the 503..... You should be able to pick up a set on here used.

 

Well, it appears I have at least one problem. Initially, the pump made enough pressure that it blew gas out in a spray out of the Schrader valve. Now it just...ejaculates. I don't know how else to describe it. It was a brand new pump. Stock replacement for TPI.

Do you think I damaged the pump during initial startup? It ran dry for a few second (8-10) until it started sucking gas. I guess I didn't have enough gas in the tank. If so, it's a twenty minute fix to change it. Should still be under warranty.

I got the car to start with some starting fluid. Fired right up! I know the problem is fuel, for sure. Going to first double-check the ground next to the tank and then change the pump. After that, going to pull the fuel rail and start checking the injectors. It's close, now!

And man, did it sound great.

 

Check it with a pressure gauge.

 

Fred,
I'll pick up a gauge probably tomorrow and check but it isn't looking good. I doubt it has more than 10psi right now. I'll report back tomorrow.

I'm going to have to send you a few bucks for your time. You've been very helpful.

 

Why replace the fuel pump?????? Why change anything without further testing? As Fred alluded to earlier.

 

speedygonzales,
The fuel pump is new because I was running a carb on it before the EFI swap. I haven't changed anything yet.

Tonight I went to Autozone and got a set of noid lights. The harness flashes the noid light once for a second and the light doesn't come back on no matter how long it cranks. Every time I crank the engine it flashes the noid light once and then never turns back on. There is no change between left and right banks on the fuel rail.

Am I wrong in thinking VATS isn't 100% burned out with my AutoProm? The fuel system 'was' making good pressure but it isn't making barely anything now. I don't have to have my laptop hooked into the AutoProm all the time, do I? I'm not really concerned with the fuel pressure. I also got a fuel pressure testing kit and will play with it tomorrow.

The noid light concerns me the most. That sucker should flash like crazy. A single flahs and never coming back is the biggest problem.

Thanks,
Colin

 

Sounds like it could be DTC 16. The ECM will attempt to fire the injectors for two revolutions of the crankshaft, and if it does not see the Opti signal it will shut down the fuel system. Do you see 4 injectors flash at the same time, indicating the 93's barch-fire injection?