'97 Vortec 7.4....need some help to diagnose

[DEMON44]

OK have '97 CC dually with Vortec 454 and NV4500 stick. Need help to diagnose. Been having an engine vibration since I got it.

first plug wires were rotted out and arcing. so changed them out. helped some. Now still have engine vibration. and just got CEL, said bank #2 running lean. So shot manifolds with temp gun. driver side all got to 300* quick and even.....

but passengerside
ambient 32*

#2 virtually no temp increase ~43* maybe just from compressing air

#4 slight temp increase 67*

#6 got to 200*

#8 virtually no temp increase.



.........so why? all injectors on 2 bank bad? is there separate drivers for each bank? got one bad? I did run an injector cleaner cycle after changing the plug wires........not a bottle in the fuel tank kind but a real hook up to the test port on the fuel rail, disable the pump, and close off return line. run off a pressurized bottle and regulator. no real change.



any ideas? I'm not sharp with gas engines.


thanks guys.

 

[gettinwestern]

maybe try swapping the injectors from side to side ? dunno

 

[DEMON44]

didn't even think of that......good one. are the injectors under the valve covers? or in the intake?

 

[gettinwestern]

They should be in the intake, probly under some fancy cover that says Vortec. Been a while since i looked at one.

 

[DEMON44]

Hmm thanks, I'm such a FI dummy. My intake look similar to those but different.

 

[daleearnhardt01]

Hmm thanks, I'm such a FI dummy. My intake look similar to those but different.

Those are small block intakes...

Your injectors will be on the outside on the fuel rails..

 

[Russell]

Go rent a noid light kit from Crappy Tire, and make sure that all of the injector drivers are working properly. A noid light is just a little LED bulb that you plug into each individual injector plug, then you start the truck and make sure that the noid light flashes.

If all the injector plugs make the noid light flash, then I'd be checking my fuel pressure next. If thats all good, I'd be confirming that all my coil packs fire properly (if so equipped, if its a cap, it is probably good if half the engine runs properly), then getting into taking off the injector rail to have the injectors tested.

Did this problem just appear out of the blue, or has it been a problem for a while?

 

[DEMON44]

been on since I got the truck, now I'm starting the find and repair mission.

Its a cap, the plug wires come 4 straight off each side. the plug wires that I took off were rotted to all hell. pulled the clips right out of 3 of them. 1 wire on the passenger side was arcing on the head in 2 separate spots....so I know that side was getting power to at least 1 plug


ok now crappy tire, what exactly is the tester called? noid tester? solenoid?

thanks brother.

 

[MTChevy]

noid light

 

[MTChevy]

and with the 97 you get to pull the intake to get to the injectors, pull the little vortec cover etc etc... but did you make sure it was spark to each hole first?

 

[Russell]

Yeah, just did some looking, and it appears you have to pull the upper intake off to get at the injectors, so I'd be checking fuel pressure and ignition before going after the injectors.

Once you do pull the upper intake off, check the injector driver function with the noid light, then if that checks out, pull the injectors and have them tested / cleaned somewhere.