spark plug wires , timing, and mpg

[deftool]

i recently replaced headgaskets on my car. when i put everything together, it would only crank but it wouldnt start. i tried everything, took me a month to figure out the owner before me had his plug wires set up a completely different way and is timed according to the way he had set up his wires. ( i dont even know if that is ok to do?)


could this be why i blew my headgasket in the first place when supposedly the engine had just been rebuilt? could it be why i get 8-10 mpg without gettin on it. i see people with 20 - 25 mpg and im not even close to that. even though i do have a bigger cam and a 4.1 liter, what kind of mpg could i attain if running properly. id also get knock at 12 lbs of boost, which i couldnt figure out why at the time.

the car is running right now with that plug wire setup, but i doubt im suppose to. am i going to damage it buy continuing to run it like this? im so short on money right now, which is why i havent redone the timing, but if i got no choice to , then i gotta do it.

just trying to get this thing running how its suppose to. :frown:

 

[TurboDave]

Plug wires go this way:

 

[deftool]

Plug wires go this way:

this is the same diagram i used to put wires back on after the headgasket install. it would not work at all.

i had to guess how the previous owner had them on before to finally get it running. thats why it took me so long to figure out what the problem was.

 

[just plain john]

The firing order is what it is, the wires should only go on one way. Is the cam sensor in correctly?

 

[deftool]

The firing order is what it is, the wires should only go on one way. Is the cam sensor in correctly?

since the car ran fine (or atleast i thought it did) before the headgasket blowout. i assumed the cam sensor was right. but i have yet to put a cam sensor cap to see where i stand. i think this should be my next buy.

i just dont understand how its running ok with the wires set the way they are. doesnt backfire or bog down or sputter.

 

[TurboDave]

Possibly the wiring between the module and coil pack is wrong. You've sure got some wierd issues.

Make sure it's in accordance with this diagram.

Sorry about the picture size, I can't seem to get it better.

 

[deftool]

Possibly the wiring between the module and coil pack is wrong. You've sure got some wierd issues.

Make sure it's in accordance with this diagram.

Sorry about the picture size, I can't seem to get it better.

yea no problem, ive used that diagram as well on all three of my ignition module coil packs. haha

i thought it was my ignition module for sure, ive got the original , an aftermarket one from nos4gn, and a brand new ac delco one. all three work the same. all wired the same to this diagram.

 

[TurboDave]

I guess the obvious question at this point then is: Exactly how are your plug wires run?

 

[mikestertwo]

I guess the obvious question at this point then is: Exactly how are your plug wires run?

+1

 

[deftool]

I guess the obvious question at this point then is: Exactly how are your plug wires run?

valid point.

DRIVERS SIDE

PASSENGERS SIDE

 

[deftool]

another bit of information,

when i had the plug wires ran the correct way. i was able to get the car to turn on and stay on for a total of 4 times, through out the hundreds of cranks i tried probably within the 3 or 4 weeks i was looking for the problem.

 

[mikestertwo]

I would say your cam sensor is off. It looks like it is starting the sequence on the wrong coil. Check the setting on the cam sensor...make sure it is set 25*ATDC on #1 CYLINDER. Also make sure you have the wires between the coil pack and ignition module on correctly. Your sequence is starting on the center coil....should start on the left coil (drivers side). This tells me #1 cylinder is the first one in the sequence....#6 cylinder should be the first one.

 

[mikestertwo]

Check to see if the cam sensor is set for 25*BTDC instead of 25*ATDC on #1 CYLINDER

 

[deftool]

I would say your cam sensor is off. It looks like it is starting the sequence on the wrong coil. Check the setting on the cam sensor...make sure it is set 25*ATDC on #1 CYLINDER. Also make sure you have the wires between the coil pack and ignition module on correctly. Your sequence is starting on the center coil....should start on the left coil (drivers side). This tells me #1 cylinder is the first one in the sequence....#6 cylinder should be the first one.

do you know what kind of difference it makes if its starting on the wrong coil? think its contributing to my low mpg?

regardless, ur right, i need to reset my cam sensor.

 

[novaderrik]

is your car set up with the 84-85 configuration for some reason?

 

[deftool]

is your car set up with the 84-85 configuration for some reason?

i didnt know they had a different configuration..

would the 4.1 block have anything to do with it?

 

[mikestertwo]

do you know what kind of difference it makes if its starting on the wrong coil? think its contributing to my low mpg?
regardless, ur right, i need to reset my cam sensor.

I think your injectors would be pulsing at the wrong time when they are in sequential mode. Don't know if that would contribute to bad gas mileage. I never tried it.

 

[hesermon]

I think your injectors would be pulsing at the wrong time when they are in sequential mode. Don't know if that would contribute to bad gas mileage. I never tried it.

A footnote: if your timing is off the injectors will never go into sequential mode, the ecm will keep it in batch to keep it running. That would be terrible for gas mileage.

 

[novaderrik]

i didnt know they had a different configuration..

would the 4.1 block have anything to do with it?

the 4.1 won't affect it, but the 84-85 cars put the plug wires on different terminals of the coil for some reason.

 

[hesermon]

the 4.1 won't affect it, but the 84-85 cars put the plug wires on different terminals of the coil for some reason.

the reason the 84/85 plug wires are different is because the coil/module is mounted on the front of the engine and backwards from the 86/87 with 1-5-3 across the front of the coil where as the 86/87 has 4-2-6 across the front. Firing order is the same.