Fast98Z28

I am going over to check my wires tonight. My tuner will be there to read and trouble shoot. if nothing goes tonight, then this weekend we are checking the pushrod length. thanks again

Fast98Z28

I have looked a few times for these colors on the harness... What exactly am I looking at? pic? Am I looking at the wires? or a certain color on the connectors?

Fast98Z28

Anyone? I want to start with the simple stuff, but after looking at the wiring last night i could not figure out the colors you speak of. Is is a single wire somewhere? Coil pack harness? engine harness for injectors? is it the white connector?

poltergeist 02

iTrader: (65)

he was talking about the coil pack harnesses. check the wiring that goes to each individual coil. if the harness was flipped over and plugged into the wrong coils this could cause a no start condition because the firing order would be off. he numbered the cyliners for you to reference.

gMAG

iTrader: (1)

About flipping over the coil pack harness... As mentioned above, each plug that goes to a coil pack, has four wires on it. The colors may have faded from age & heat. Mine were reversed, but the engine still started. I could see a scenario where, depending upon the cam/timing events, that certain cylinders would not ignite.

badazz81z28

iTrader: (6)

I thought it was determined that he could get one side of the engine to run. So How can the coils be reversed?

Fast98Z28

No luck tonight. I checked the harness's and one side was flipped. I believe I have them connected right. Went to crank it... and nothing. Was having a hard time turning the engine over, so I got a new battery and starter. Installed them and tried to crank it over again. This time it was much faster and enough to where the engine should have started... but nothing. No backfire or any signs of life. almost like I am not getting spark. I know there is fuel, I can smell it. So tomorrow I am going to try to crank it over hoping maybe the plugs might have gotten wet, maybe it will try to start. If not this weekend I am pulling the valve covers and checking pushrod length.

This is such a PITA! I just wanna drive her...

gMAG

iTrader: (1)

Can you duplicate the test, where you disconnected one cyl bank, then were able to fire up the other bank? As someone else said, check your grounds, & possibly a ground which was never connected (for the bank that didn't fire at all).
Also, you said, "I have not driven the car since last April". Injectors sitting more than a few months can clog up, or deliver a dribble of fuel. A faulty spray pattern can cause a no fire.
Just putting out some ideas for you.

moeZ28

iTrader: (7)

Did you check the grounds on the back of the driver side head as I suggested before? There is only 2 ground wires, but there should be 3 eyelets to ground back there.

Fast98Z28

going to check all the grounds tonight, and duplicate the test. If the engine fires on one bank, then i know there is something with the drivers side. I am going to take the passenger's side wires off and see if the drivers side will start. and then vise versa... that might indicate if it is just one bank or both.
As far as it sitting since april, i did start it 2 months ago, and was able to drive it to my buddies garage... ran fine... just with a knock. So i want to say that the injectors should still be good... i know i am getting plenty of fuel. Maybe this all comes back to the 7.4 pushrods and not allowing the valves to open properly... idk. thanks for the input.

gagliano7

Did you ever check if you are getting spark? I would check that before going any further.

Fast98Z28

well i was definetely getting spark when flames were shooting out of the intake, so im assuming that is not the issue. but since i put the coil harness in what i believe is the correct way, it doesnt seem to get any....

sreve

iTrader: (3)

the coils and injectors or fused per bank
something else to check.

badazz81z28

iTrader: (6)

I usually pull a plug and stick a screw driver in it and place it near a ground to check spark.

Since this is a new enigne...Be cautious when trying to fire it. Since spraying a large amount of fuel in the engine is washing out the cylinders. Disconnect the fuel source and make sure you have spark.

joecar

If it's a 1998 F-car, then the LHS and RHS coil subharnesses are slightly different, you can't interchange them.

Fast98Z28

So, last night i double checked grounds, harness, plugs, wires.... all checked out. I decided to check spark, went to crank it, and it cranks really slow again (new battery and starter) and no spark on either side now? this doesnt make sense as it did start randomly on the passenger side bank saturday. so i am dumbfounded. I am going to have a buddy of mine (mechanic for 30+ years) grab some tools from work and come over tomorrow to hopefully help diagnose whatever this could be. sigh.... i am not gonna give up on this thing!

badazz81z28

iTrader: (6)

Did you mention who worked the harness? Did you do it yourself?

Fast98Z28

I did it myself.

gMAG

iTrader: (1)

First thing...there seems to be parasitic battery loss. Check your battery voltage. If seeing less than 'normal' battery voltage, re-charge the battery. Then place an ammeter in line with the battery, and verify whether you have ongoing drain. If so, pull fuses/open the circuits, until the loss stops.
Shoot one trouble at a time.

gMAG

iTrader: (1)

Ok, since you verified the small harnesses, those are now ruled out.
There can be more than one trouble, here.
A "Hot in Run ", pink lead will supply battery to both the coils, & to the injectors.
As someone mentioned, there is a separate fuse for each bank...one fuse supplies battery (through pink wire) for coils & injs of bank #1, & the other fuse supplies (through another pink wire) for bank #2.
On the bank which did not fire, 'rent' a noid light set from AutoZone/O'Reilly's etc, and verify that while cranking, you have PULSING/flashing noid light, and that the lamp is not on, steadily (or, that the lamp is off full-time). Check each injector on this bank.
Then, on the same bank, verify that you have spark at each coil.
I'm guessing from your original result, that something on the battery side of the defective bank is amiss.
Since at least one bank fired up, after disconnecting the other bank, it cant be the crank sensor.
Hope you don't mind the info overload!