View Full Version : problems fuel now ignition

02-28-2006, 05:22 PM
just wondering if anyone had any ideas on this...

I installed a SAFC-II on my car(90 gsx) and about a week after I got a check engine light and the car started Hard starting when cold(I had to crank it atleast 30 sec to a min just to get it to run rough). so I started thinking and decided it was a leaky injector flooding out a cylinder. well I pulled the fuel rail and primed the fuel system with all lines hooked up and #3 started dripping. I replaced the fuel injector and now all of a sudden my 2 3 coil stopped firing so I'm running on 2 cylinders, I replaced both coil packs with used ones off a running car and the one coil still isn't firing. so I can't see if it even was an injector problem. anyways I started throwing wrenches so I decided to take a break and see if you guys had some input

thanks vinnie

Bryan Savage
02-28-2006, 06:39 PM
Lets see here:
1) SAFC2 installed
2) check engine light a week after
3) long crank time
4) dripping #3 injector (replaced)
5) coil no-fire (known good coil tried)
6) throwing wrenches

Hrm. For starters, remove the SAFC. I'm not saying you hosed the install or that you've got bum parts, but if something was working fine before I touched it and now it's not working so fine anymore, it's my fault somehow. Was it running fine for that first week? Did you make any huge changes to the tables?

What code was the MIL for?

Thirty to sixty seconds cranking?? At least we know it's not your battery causing you problems.:)

As for the injector, was the fuel coming from the pintle, or did the seal perhaps loosen when you pulled the rail up? Did the replacement leak too?

Was your coil not firing the whole time, or did it somehow quit working after you swapped injectors?

Sounds fishy. Again, pull the AFC. At least un-splice the "air flow" wire. The rest only monitor, so they *shouldn't* cause problems. The correct wires were tapped, right?;)

02-28-2006, 06:51 PM
thanks for the response...

I already tried un-splicing the afc from the air flow signal but I was dumb and did it at the same time as I replaced the injector

yes it ran fine for the first week after the afc I didn't even get a chane to play with the fuel parameters yet.

I don't know why but I've never been able to get my data logger to work on my 90 and I tried pullin the code with an analog volt meter and got nothing the needle never even moved.

as for the leaky injector yeah it was definitely coming from the pintle and not the upper injecor seal.

And the wires were connected correctly all the readings in monitor mode were fine.

I was also running the jdm ecu and tried switching it out with the usdm and no change


Bryan Savage
02-28-2006, 07:12 PM
So then we can rule out the injector and the AFC, and the ECU. Regardless of whether it was the injector leaking or something else causing it, it's not doing that now, so we can cross it off the list.

That leaves the problem with the coil packs not firing. Or the single coil pack, anyway. Don't worry about the MIL for now, as perhaps it had something to do with the injector problem.

How do you know the coil is not firing? Have you tried pulling the spark plug wires one at a time and lying the ends on something metal and then cranking the motor? Hopefully either the car runs or you've got a friend to tell you. The wires will arc to whatever metal you set them on. That's the simplest way of checking if you've got spark.

While the wires are off, you might yank the plugs right quick to make sure that #3 didn't foul itself out.

02-28-2006, 07:27 PM
yeah I tried pulling cylinder 2 and 3 one at a time while i was running on 2 cylinders and neither one of them would arc...

thats how I concluded the one coil wasn't firing... I'm just confused how one coil gets the signal to fire and the other doesn't...

I've had 1g's for 7 years and never had one coil fire and the other not... just wanted to know if someone else has heard of this

Bryan Savage
02-28-2006, 07:45 PM
That's strange. I suppose it would be unlikely that swapping wires would help any... Not with two cylinders down...

Is it possible that in working with the fuel rail, you inadvertently knocked a grounding wire off the back of the coilpack, thusly disabling the 2-3 coil? I don't see how really... maybe one of your thrown wrenches hit it?;)

At least on my '92, there are only three wires for both coil packs. A ground, a signal wire for the 1-4, and the other one for the 2-3. You could try back-probing the 2-3 signal wire to see if there's anything there.

I guess just start working backwards?? Coil pack --> signal wires --> transistor chip thingy --> ecu.

02-28-2006, 07:47 PM
alright man thanks for the help!!


Bryan Savage
02-28-2006, 07:50 PM
Good luck hoser! Let us know what you find, eh?

03-01-2006, 04:38 AM
Check the power transistor as well.

03-02-2006, 06:15 PM
alright I got the car running again!! this thing has cost me 4 drunken late nights but I think I got the major bug's out...

First tonight I started by replacing the power transistor but as i was in the process I noticed severe corrosion on the connector and the unit itself, well I replaced the transistor and cleaned up the connections and sealed them... as I was putting it back together I noticed the insulation on the wires was hard and frail and was falling off(good old 16 years of heat I guess). The three wire's that were exposed I used electrical tape to seal up( I know not the best choice). I got all of that done and decided to look at the wiring to the coils.... sure enough not only was the insulation coming off but one of the wires was broken at the main wiring harness splice(wouldn't you know the signal wire for the 2-3 coil) I didn't notice it before because I only checked the wires at the connector to the coils itself.

Anyways I got it runnin, I took it on her test drive and just my luck the harmonic balancer let loose on me

got that replaced and drove it again and no check engine light... until I hit some bumps and now it comes on and goes out everytime I hit some bumps... but it's good enough for now...

thanks for all the help guys