2,4,6,8 are firing and pulsating ,I'm thinking, a short maybe, Ignition module going bad or ECM computer any suggestions would be greatly appreciated thanks, Firing order good and compression is 200 in all cylinders no codes whatsoever no ses light either just running off 2,4,6,8 cylinders right now and they are being flooded with fuel but 1,3,5,7 are not getting fire or fuel or something please help

 

i would start by looking at the grounds on the back of the passenger side head. there should at least 2 wires black/white.

other than that i really cant help you too much because you didnt state what engine you have

 

DID YOU CHECK THE INJECTOR FUSES.. THERE IS 1 FOR EACH BANK

 

Yes, I agree, check the fuses first. INJ1, INJ2

 

5.7 350tpi grounds appear to be connected and snug on backside of head,so any other help is appreciated thank you

 

Fuses are good I have checked evrything I know of its gotta be the ecm,ignition module or bad injectors but they are pulsing on 2,4,6,and 8, but nothing out of the 1,3,5,and7 ok on the ohms though no check engine light ,it did have a code 13 but I replaced theo2 sensor and no codes now but its only running off the 2,4,6,8 and the plugs are black and gas smell bad too much fuel,and the 1,3,5,7 are not working at all plugs still look new since 2 days ago any more suggestions are welcome thanks

 

You must have an open circuit somewhere between the fuse and injectors or the injectors and the ECM.

Both sets of injectors are fired by the ECM grounding one side of the injectors. The Injector driver is common to both of them. That is to say, there is only one injector driver that fires all 8 injectors at the same time so I'd doubt very much it's the ECM and the chance of having 4 bad injectors on one bank are pretty remote.

To have one bank firing and not the other suggests a wiring issue. See if you can find a wiring diagram (just google for it but also have a look in the ftp site at www.diy-efi.org/gmecm ) and you'll see how the injectors are wired up to the ECM.

 

Thanks I'm going 2 check that info out and I'll post further prognosis on conditions that I'm dealing with what about the ignition module I know it is mainly used for start up conditions but it does have control over the injectors operating right

 

both fuses are good its a 350tpi and all injectors on driverside aren't working and passenger side are but plugs are black as night and its running on 4 cyl's

 

You said you checked everything, but did you? Just because the fuse is good that doesn't mean there's 12 volts on either side.
Is there 12volts at the injector connectors of the non-functioning side?

The engine ground behind the heads isn't a problem because injector ground is driven to ground through the ECM, which is why 4 injectors are working. As long as the ECM has a ground path to the battery the injectors will work; assuming no wiring problems.

Since the grounds are connected together internally to and driven by one driver in the ECM there's no reason you can't connect them together in the engine bay. Run a temp wire from the working side ground wire in the harness to the other side, that will bypass any break in the wiring.
If it works you know the break is between the last injector ground to the ECM.

 

thanks I ran my probe light from the ground on the back of the head where there is 3 wires and got a signal so I'm thinking its the ground wire from the block 2 the injector harness on driverside, if you think otherwise please let me know thanks

 

wiggled wires on head and seems to have fixed injector problem,thanks guys, it did throw a egr 32 code 1 time and i cleared it with the scanner and it hasn't come up again so I 'm not sure any suggestions thanks

 

check the resistance. should be between 11-14ohms sometimes 16. and check the tps voltage. maybe check to see if the injectors get power. slap the ecm and MAF, hell slap the plenum jk.sorry dude, i hate it sometimes but, maybe its worth owning if i get looks by women. its definatly a ground. i would think. just makes the most sense. if any are out of resistance and you have to swap them.. i recommend venoms, i got some venoms, i like em, noisy but i thinks thats the swap on the in tank fuel pump connection..i went with a hose over the pulsator. i like stock the most. maybe the ecm groundd its own internal relays. but 9/10 times thats never the case, but rather a wire leading to the injectors. on fuse, wherever. you prolly know this, but change the oil after your done fixing your ride, and becare about the cat converter. it burns up with lean fuel.

 

aint got any cats ,except the one that meows his name is Buster, it was a ground I got it figured out though, thanks for your input I thought of a ground problem but chasing which would be bad was the pain in the butt, I'dve rathter had to replace the ecm it ain't but 61 bucks o2 20 bucks, I'd rather know whats bad from scanner test then having to chase wires but I figured it out

 

Glad to see you got it straightened out.
If you haven't done it already, you may want to remove that ground wire/s and clean it up with a wire brush to prevent it from happening again.

 

will do thanks for the helpful info

 

The probe will light if you make contact with any metal part(s) of the engine that are connected to the battery ground path, so that test doesn't really tell you anything.
The injectors do not have a ground wire connected at the back of the head. One wire of the injector connector goes to the fuse the other wire goes directly to the ECM not engine ground.

 

Well whatever wires they are attatched to the back of the pass head I adjusted and it fixed my problem so I'm not sure i just know I can go fast again

 

i know this is a old post,but after reading this,i think i have the same problem.knowing i checked the volts at the wires,i am getting 13.50 on 1,3,5,7 but would that still mean anything?could i still have the same problem?

 

Check the fuel injector fuses there are 2, one for 2,4,6,8, and one for 1,3,5,7

 

WELL I THINK I FOUND THE PROBLEM TODAY.SO FAR 1 INJECTOR HAS A READING OF 0.06 WHEN THE OTHER ONES R 0.16

 

Where are these fuses located? And how do you check voltage with key on or off?

 

Left knee under dash fuse box, 10 amp fuses labeled INJ1 & INJ2, key on to test, probe both pin holes on top of fuse for voltage or pull fuse and check for continuity, but 12volts or more at all injector connectors means the fuses are good.

 

Thanks I had 16 ohms at each injector but didn,t know when the voltage was applied

 

Voltage is applied when the key is in run/start, but current is drawn until the ECM sinks the voltage to ground through the drivers.

 

Thanks again RG looks like I might have a lot of troubleshooting to do Sat, This is my first tpi to work on how do the injectors come out if they screw out what size wrench is used ? My car is an hour away so trying to cover all bases.

 

in order to get at the injectors,ur going to have to remove the upper plenium first.u need a t40 torks socket and a deep 10 mm socket.make sure u drain the rad because of a few water lines connect to throddle body.after that u have to remove the left and right runners which u need the t40 for again.have fun getting at the 2 hidden bolts that hold the runners one.far right rear is by the distributor,the left front is behind the alt.after that then u have 4 10 mm bolts holding the rail on and also in the front just below the thermostat housing is a 15 mm bolt holding it to the front of the intake.then of course u have the fuel lines to disconnect.once u have the rail off,u will see small little clips holding the injectores in.with a small screwdriver,u push on the clip so that it slides around to unlock the injector.then carefully pry it out of the rail.hopsfully that helps u out.

 

helps alot glad you gave advice and tools that I need Thanks

 

The hidden bolt tabs are circled in black in the first picture.

I replaced all the torx bolts with grade 8 SS Hex socket metric bolts and replaced and rerouted the fuel lines with 3/8" SS tubing after modifying the stock fuel regulator base so that the Holley adjustable regulator mounts vertically instead of at the stock angle. I also replaced the injector retainer clips with "C" clips because the stock clips wouldn't stay in the locked position and a few were missing. Disconnect the lines at the regulator and the end of th fuel rail and lift straight up.

I didn't care for the coolant passage hose barbs sticking out so I completely deleted the passages from underneath the Throttle Body. The barbs you do see are for the canister fuel vapor line and the valve cover breather hose.

 

well glad i was able to help.i just got done doing that all on sunday.i did cheat on replacing one injector.i didnt remove the runners.lol.rgarcia63 that is a nice looking intake.did u buy it like that or do it urself?i have spare TPI parts and would love to make mine look like that.

 

Hope I dont have to pull the injectors out maybe electrical problem but now I have a good idea how to do it if need arises Thanks again. Dusty