Is there any way to tell which plugs go to which injectors? I've got the pink wires on the right bank, and the green wires on the left, but only one wire on each side is different from the other two.

I'm becoming desperate for ideas as to what I might have done wrong with my 3.4 swap to produce a drop of 6mpg and cause vibration at idle. Not a huge vibration, just enough to make a few things in the dash rattle and feel it in the seat. (Unless the headers are creating that much noise)

I've replaced most of the vac system hoses, checked the vac solenoid as per 2.8boy's instructions, and replaced the PCV valve. Checked the fuel vapor solonoid too. I'm thinking about plugging the hose going to the Cruise control stuff just to isolate all that.

Alignment was off a little, fixed, no results
Finally got enough miles to switch to synthetic, Royal Purple added, no results
New cap, rotor, plugs, heated o2, no exhaust leaks, fuel pressure good, new injectors, new temp sensor.

Nothing has really helped so far. There are some more things I did, but I can't think of them all at the moment.

Tranny is new also, RPM's read as they should, tv cable adjusted and checked by the tranny shop that built it.

Only thing I can think of is the half-a$$ porting job I did to the heads. I basically created slightly wide spots where the intake manifold goes into the heads. I'm in the process now of cleaning up the old heads in case it comes to that.

 

i hate when stuff goes that way. hang let me check on here i had a diagram for the injectors that migh help you.


no dice on the diagram it doesnt show the order.

 

Yeah, my manuals only show pink on one side, green on the other. I'm sure if I had a couple crisscrossed, it would run waaayyyy worse than it is now, but I'm just trying to come up with everything I can, in hopes that one of my many crazy theories actually ends up being the culprit.

Vac leak somewhere is still my strongest suspicion.

 

yeah vac leaks are a pain. you just got to take your time and go cover one pieve at a time and double, tripple check everything. even after all that you still will think you missed somthing though.

 

it doesn't matter as ling as one color is on one side. Our computers have 2 injector drivers and fire each bank independently from the other. There is no particular order, so just put them where they fit, you shouldn't have a problem.

To check for vacuum leaks, just get a can of carb cleaner with a red spray tube so you can direct the spray, you'll find the leak really quickly if that's the case.

 

If it is a '7730, the ECM batch fires, not bank fires. Meaning that all 6 injectiors fire at the same time. If you follow the injector leads inside the ECM, you will find a large solder joint that bridges the outputs of both injector drivers, which combines both outputs as well. I believe other similar ECMs will have the same property, though I haven't verified other service numbers.

 

Then I must have a different ECM because I don't have continuity between the different driver wires, and they're all firing. I've never changed it out, but I do know a that they fire seperatly on mine.

Anyway, my point was that it doesn't matter where the wires go, as long as they clip on, you'll never notice a difference.

 

Huh, I didn't realize that. I was assuming each injector fired individually one at a time as the intake valves opened on each cylinder.

Thanks for clearing that up.

As for the vac leak, I was just out there with a vac pump/gauge testing everthing I could. Cruise control isn't leaking, charcoal cannister lines and components seem good. Line going to vac switch holds vacuum.

Pretty much all I have left now is the crankcase hose stuff. I'll try out the carb cleaner on that.

 

Sprayed carb cleaner around the big vac lines by the distributor, brake booster, several other spots, air intake, egr, plenum gaskets, nothing changed the rpm. I might try it again later to be sure, but I don't think I'll find anything. I'd like to try that smoke test though.

I guess I focus on the few remaining sensors I haven't changed yet. air temp sensor (looks dirty and corroded a tad), MAF (several people told me I need to change that to one made for a 3.4, but 3.4's used MAP unless I'm mistaken, besides, nobody else who did the 3.4 swap changed it.)

There's a few others I can't think of at the moment.