2g Electrical problems, no spark??

[steel_3d]

Ok, I just bought a 97 gsx that doesn't start, and I gotta figure out why.

Apparently it was running fine until the dude removed the safc and put the stock injectors back in. Presumably some wiring got messed up in that process, but the guy doing it didn't know enough to be of help. The owner couldn't figure it out and that's why I own it now.

The engine was rebuilt not long ago (6-bolt, was running after the conversion apparently), good compression, correct looking timing belt etc. The engine fusible link is good, though I haven't checked all the fuses yet. Radio and dash works as expected. Apparently it's go the 97 ecu.

The main symptoms are that the engine cranks but doesn't fire. No spark, and I couldn't smell much if any fuel either from the spark plug holes while doing the compression test.

With the key on the boost gauge comes up to 0, which tells me the ecu's doing something and isn't completely dead at least. The weird thing is that the rpm's jump to about 2000 and the speedo to about 50mph (they're sitting a bit higher than 0 even with the key off since the gauge cluster was messed with to take out the indiglo shit and put it back to stock, and I assume the needles weren't put back to line up to 0, if that's possible).

That's all I can think of to describe the problem. I haven't tried troubleshooting it yet. I have another ecu and gauge cluster I can try tomorrow. I used to have a 1g so I dunno much about 2g's. I'm just hoping you guys could give me pointers as to where to start looking. I have a multimeter, and I can possibly hook up an oscilloscope (laptop software, if you guys don't think it'll blow from the car's electrical system), so if you guys can suggest what to check I'd be really thankful. I have some ideas but want more

Thinking about it, if the ecu's working and there's no spark or fuel, it's likely not getting an rpm signal (bad cas or messedup rpm wire from safc uninstall?? that's likely). If the maf signal was messed the car would still spark right, and even run crappy? Could it be anything else? Do you guys think a scantool or logger would help with something like this? Dunno anyone near LA with a 2g logger...

Should the tach bounce while cranking? I haven't checked this but will tomorrow.

Ok, I'll stop my rambling, just shoot me ideas, I'd appreciate it immensely!

 

[Raph]

installing the safc involves splicing into the mafs wiring going to the ecu.. maybe the gguy didnt put the wiring back together..

on Vfaqs theres a wiring diagram from the 2gs ecu..showing excatly what wires you have to splice into.. its 5 or 7 wires, just check them (at least the mafs wires) ,the problem might be there.

edit: go outside and check it now,you live i sunny CA

just remove the drivers kickpanel and check the ecus plug wiring.. especially if the guy half assed them back together and they probably came apart.

 

[98eclipseRS]

installing the safc involves splicing into the mafs wiring going to the ecu.. maybe the gguy didnt put the wiring back together..

on Vfaqs theres a wiring diagram from the 2gs ecu..showing excatly what wires you have to splice into.. its 5 or 7 wires, just check them (at least the mafs wires) ,the problem might be there.

edit: go outside and check it now,you live i sunny CA

just remove the drivers kickpanel and check the ecus plug wiring.. especially if the guy half assed them back together and they probably came apart.

That's what my first thought was. There is one wire you have to cut to make the afc work and from what it sounds like the guy you bought the car off of was an idiot and so was the guy he had working on it. However, a dsm will run if the maf is not plugged in it will barely idle but it will run so it sounds like they ####ed something else up. Have you checked all the fuses and relays? He might have shorted something out and it blew a fuse and that's why it won't spark. Also make sure all the electrical connectors are plugged into the right place. One of the stupidest mistakes me and my buddies have ever done while in a hurry to get a car back together was plug the injector harness plug into the air conditioning plug. They both look the same but ti will keep you from getting fuel.

 

[steel_3d]

That's good, I'll check that plug. I was obviously gonna check over the afc wiring and fuses. Any other ideas? Regarding the weird tach and speedo, etc?

 

[Raph]

That's good, I'll check that plug. I was obviously gonna check over the afc wiring and fuses. Any other ideas? Regarding the weird tach and speedo, etc?

either the batt is dead or the batterys connectors are loose , or like you mentioned,the guy had indiglo speeedo gauges on it before and the needles arent aligned

injector harness plug into the air conditioning plug. They both look the same but ti will keep you from getting fuel.

been there too man

 

[steel_3d]

So low battery voltage makes the tach and speedo jump up when the key is on? Good to know..

I was moving my girlfriend all weekend and dind't get to look at the car It'll probably be next week till I get daylight to look at it, but your ideas are much appreciated!

 

[98eclipseRS]

been there too man

haha I felt so dumb afterwards too.

 

[steel_3d]

Is the tach supposed to bounce while cranking?

 

[steel_3d]

I didn't see a plug for the injectors. You guys meant the coil pack plug and the ac plug are the same, right?

It seemed like the right one was plugged into the coil pack. The harness for this came from around where the cas wires come out of, and it doesn't seem like it would reach the ac compressor. The ac plug had thicker wires (I assume more current is needed for the AC than for the coil pack) and that branches off from the main harness earlier.

In the pic, the plug in my left hand is what I assume to be the ac plug. The one on the right was plugged into the coil pack.

Note, the wires for the AC plug have been hacked, maybe they burned at one point, or they needed to be lengthened. Is it normally necessary to lengthen the harness for the coil pack in a 6-bolt swap?


The great news is that the car doesn't even crank right now... I put in my good battery. It seems like there's a good enough connection, but the tach and speedo still jump up with the key on. When I go to crank all I get is the radio turns off. The dash lights, map lights and headlights don't dim though, which makes me think it's not even trying to crank. I get the same effect with the clutch in or out. Any ideas? The car was cranking the weekend before I got it, but I dunno if the guy's touched anything else after that.

 

[steel_3d]

Ok, I got the car running. Sure enough, it was the AC plug plugged into the coil pack originally. And the gas tank was empty

Still doesn't start unless I jump the starter straight to the battery, but that's a different wiring issue, probably having to do with the half/disabled viper alarm.

Thanks for everyone's help!