97 vortec trouble, mt2500 where are you?

[bracketshark]

As in my earlier thread I've replaced yet another intake gasket on a vortec 5.7 motor. This time it turned out I had to replace the whole intake with a unit that was supposide removed from a running motor due to damaged water passages. The installation was completed and the only thing I did differantly from other changeouts was I steam cleaned the entire engine compartment before I even tried to start the motor. My problem now is the motor will spin over with the starter and I have fire to the plugs but it doesn't try to start unless fuel is dumped into the throttle body, then it runs but shortly of course. I have verified fuel pressure to be 62 PSI, last night I checked that the cam sensor in the distributor has power going to it and even went an got and installed a new sensor rather than trying to verify the old ones operation discribed by my chiltons manual. Still no start, I verified distributor location I'm confident its in correct phase. I read in the chiltons manual that the cam sensor only reads position of #1 cylinder and all injector firing sequence come from this one reading and the computor controls the rest, at least I think thats what it ment. could I have a bad computor, could the injectors in this intake just be bad, is there a way to check power at the plug going into the injectors? I don't know what else to do I'm stumped. If anyone has an idea please share it this thing is driving me nuts. Thanks

[maxwedge]

Check all the fuses for the pcm/injector circuit? harness connectors to the injectors.

[bracketshark]

I checked the ones under the hood, I think labled ecm-1 and ecm-2 they are good, I've unplugged and reconnected the (16? pin) plug numorus times, nothing. Is there a way to check power to the plug with it disconnected? Volt meter or test light. This motor ran great before the intake swap, it just leaked coolant. I wonder if all this style vortec intakes and injectors interchangable.

[Jeremy-WI]

I think the injectors may have 12volts any time the key is on, the pcm supplies the path to ground when it pulses them, the injectors should be interchangeable, I know the 5.0 and 5.7 use the same injectors, the 4.3 may use the same ones- just 2 less

[maxwedge]

Originally Posted by Jeremy-WI

I think the injectors may have 12volts any time the key is on, the pcm supplies the path to ground when it pulses them, the injectors should be interchangeable, I know the 5.0 and 5.7 use the same injectors, the 4.3 may use the same ones- just 2 less

Correct and even if the injectors were different it would at least start. 65 psi is required to pop the the injectors remember.

[bracketshark]

Semi fixed it, I went to a friend of mine at the chevy dealership and humbly asked for advice. His first responce after hearing the story was change the spider. Well the spider I think is what someone else called the POD. I came home and took the one off of the removed intake and installed it on the intake on the engine. This is the first time I've ever looked under the plastic upper manifold, nothing to it. Only one bad thing I did, I took the fuel pressure regulator off of the pod a couple of days ago so I just stuck it back on the way I thought it came off, before putting it on the truck, mistake. Once everything was back together the truck started right up like it had just been switched off. I was proud, after about a minute of running it just cut off. I went to the switch and spun the motor a couple of turns then it LOCKED UP. I pulled all of the plugs out #5&7 ran fuel out the hole, I disconnected the coil wire and wiring harnes pulled the fuel pump relay and spun the motor to remove the fuel, motor spins freely now. I went to the bad injector pod and removed the fuel regulator and notice imediatly that I had left a black hard o-ring looking piece out. I hope this is the culprit of the fuel problem. I will tear it back down tommorrow night and hope when all of the pieces are back in place it will be fixed. I did hear it run though and I was begining to wonder if that would ever happen. Thanks for the help and I'll let you know about the regulator tommorrow night .

[bracketshark]

Last night I pulled the upper intake apart "again" and put that black spacer ring on the fuel pressure regulator. I put it all back together again and it runs fine. I hope my bad experiance here might save someone else some grief someday. I'm done with this part of the project, next the brakes.