candlelit

iTrader: (21)

Well this is confusing. We done a forged motor swap (8.7:1 CR) & recent LS6 intake/EGR delete in my 99 Firehawk. Front o2's not connected. Once done we were able to start it and let it run 5 or 6 times. We finally got the quick connect on the trans in so my brother turned it around in th yard. Well he didn't give it enough gas and it died (yesterday). Thought the crank sensor came loose but we checked it. We checked all possible connections and the two grounds on the back of the heads. We kinda had to rig the coils up since the bracket wouldn't fit on the older style valve covers. But everything looks connected. We tried to jump start it, and the battery already lights everything up right. There is 1/3 tank of gas & the fuel injector rail is pressurized. We haven't checked the fuses yet, (i.e. ignition relay) since we don't have a meter or test bulb. Someone said to swap it with the fan relay and see what happens. Are there other fuses we should check too? Or what else could cause us the reason to not get spark? Like I said it started up about 6 times before and now decides not to (cranks over but doesn't fire). Can it be because of the untuned pcm & low compression? What's a cheap way to tell if one of those sensors (cam, crank) goes bad?? (we currently don't have a test meter or know anyone with a scan tool). Thanks guys

candlelit

iTrader: (21)

update: he swapped the fan & ignition relays, and didn't work ??

35th SS

iTrader: (2)

explain how you rig the coils up.

candlelit

iTrader: (21)

kinda hard to explain without showing pictures. basically the valve covers are the old 97-98 style and the bracket/coils didn't bolt up in the right spot, so we had to do away with them. I would think they're fine since it started 5 or 6 times after we done everything. but I think a couple of them I had to bolt up kinda inverse (outside-in) to get them to fit along the sides of the valve covers. (the spark plug wires are connected to the coils like they should be, not upside down).

35th SS

iTrader: (2)

is it setting a check eng. light.try swapping your maf.and crank sensor.also show pics.of your coils setup.

LS1-450

iTrader: (33)

There are three grounds required on the back of the passenger side head; not 2. This is probably why you have no spark. I will look for my schematic book & let you know,.....if I can find it. In the mean time, look for the ground wire. Also, why no front 02 sensors? These are required in order to tune the car for normal driving conditions.

Ws6man2000

iTrader: (24)

ya my car did the same thing. I didnt get the pass head side grounds in all the way and car wouldnt turn over

themack56

iTrader: (70)

on my 98 they are on the driver side

LS1-450

iTrader: (33)

On my 98, they're on the passenger side. Regardless, the important thing is that there are 3 grounds.

LS1-450

iTrader: (33)

A black wire from all coils runs to #31 in the PCM & to chasis ground on the back of the head. Sorry, can't tell if #31 is in the blue or the red side of the PCM by my schematic. Although, it should be clear which when looking @ the PCM.

Coil #6 has a lt blu/white wire that runs to the PCM (ignition control). Schematic dose not denote which number on the PCM. However, you will be able to see which when you trace the wire to see. Coil #8 has a ppl/wht wire that needs to be run to the PCM (ignition control). So, just make sure it's there. Coil #2 has a red/white wire that runs to the PCM (ignition control). Coil #4 has a dark green/white wire that rins to the PCM (ignition control). Coils 2,4,6,8 all have a pink wire that runs to #13 on the PCM. Coils 1,3,5,7 have a pink wire that runs to #16 (looks like it's number 16 in the oposite side of the PCM, meaning if 2,4,6,8 go to the red side, then this looks as if it would run to the blue or vise versa. Coils 1,3,5 have a brown wire that runs to #26 on the PCM. Coil #7 has a red wire that runs to #9 on the PCM (ignition control). Coil #1 has a purple wire that runs to #8 on the PCM (ignition control). Coil #3 has a light blue wire that runs to #29 on the PCM (ignition control). Coil #5 has a dark green wire that runs to #30 on the PCM (ignition control). Coils 1,3,5,7 have brown wire that runs to #26 on the PCM.

Also, It appears that the PCM wants front 02 signal & grounds.

That's all I got. Hope this helps.

5.3LJimmy

iTrader: (10)

The plugs are probably fouled from running with no o2's(being untuned doesn't help). Check that you have all grounds connected, and if they are try replacing the plugs.

candlelit

iTrader: (21)

so how do I go about hooking up the front o2 sensors? it's odd, cause the car ran 5 times like that. so you guys mainly suggest looking for a loose ground wire behind the intake, getting the o2's hooked up (then what about the rear o2's, they're hooked up to the headers), then changing plugs?

LS1-450

iTrader: (33)

You don't need the rears for the car to run. Not hooking them up will throw a code, but, that's all. Fronts are required, as noted previously. Does your wiring pigtail has front 02 connectors? If so, just plug 'em into the senosrs you have already mounted if the sensors haven't gone bad from the poor running engine. Maybe it's better to replace them w/ the fronts you have & then connect to the pigtail.

Are you saying that the rears are hooked up to the PCM using the rear 02 sensor wiring? If they're hooked up to the front 02 wiring in the pigtail (more likely) then you did have front 02's that have gone bad.

candlelit

iTrader: (21)

well we swapped out the stock manifolds for the headers and therefore I guess we have no front o2 sensors now. we hooked up the back o2 sensors to the back o2 connectors since the headers already had them. can we just run an extension from the front o2 connectors to the back o2 sensors?? trying to figure out the cheapest way possible of doing this because I know we only need 2 sensors. or I wonder what happened to the front o2 sensors? I don't remember if they're attached to the stock manifolds or not.

by the way, that's the sickest Miata I've heard of! I love your mods

5.3LJimmy

iTrader: (10)

The o2 bungs in the headers are for the front sensors. The headers do not have provisions for the rear sensors. You need to purchase o2 extension harnesses to plug the front o2 wires to the sensors in the header collectors.