Electrical mess, or dead ECU?

[DSMcrazy3]

Alright well I've got a list of how this went down, and how I discovered things in chronological order. I'm leaning towards dead ECU being the problem, but I thought I would get some opinions and suggestions from my fellow 420a buddies.

Driving to get gas, when I think I ran out. The light was on, and the car died.

Put 3 gallons in, went to crank the car, it would turn over, but never fire. I couldn't smell fuel like you usually can when the car doesn't start.

Now I realized the fuel pump isn't priming. It's a walbro 255, so you hear it when it kicks on.

I realized in my SAFC 2, it's set on 4 channel, viewing RPM, Throttle %, Manifold pressure, and Battery Voltage. Throttle Percentage would read something like 3.5% when I actually had it at 100%. Now it doesn't read anything, just stays at 0.

Checked all fuses and found one blown, 30A it was for A/C, not sure how that is connected, but it was...

Traced the SAFC wires and realized again they had reached the EGR tube and of course it got through the main rubber insulation, and burned through the ground wire for the SAFC.

I had a kill switch wired up, found out no power was getting to the wire, the switch was spliced into the power wire coming out of the ECU. So I took the kill switch out.

Disconnected the power wire for the SAFC so it's like it isn't there at all, still no start.

Checked for power getting to the fuel pump, none.
Checked for spark, none.

Thanks for all of your help and suggestions! I'm in the process of searching for a local 2ga n/t that with the 1 plug harness, but so far, no luck.

[BigRand]

man that sucks.

Now lets back up a sec.

When you said your car died, did everything just power down and you could accelertate anymore. Like lights speedo and tac just dropped down?


If this is the case, then its definetly and EGR problem that both I and several people have had a problem with. And it has to do with the wires melting through the rubber etc. (I think you know what I'm talking about)

I'd check to see if there is any power leaving the fuse box and if so how far is it going? Chances are it'll lead right to the problem and in this case it probably is your ecu.

You gotta find all the melted wires, it might not just be next to the egr now.

[DSMcrazy3]

When the car died, it just shut off. The RPMs went to 0 immediately, now the car just cranks cranks cranks, but doesn't turn on.

Today I took off my UICP and looked all along the whole EGR tube, no wire had touched it(besides the SAFC which I already tended to)

How do I check for power leaving the fuse box?

[XMasta19]

OHHHHH.....so now who's car isn't running


I ask and ask for ## help and you laugh at me, go check wires yo....now who's posting about their problems. just messin w/ya josh, sorry I haven't been on AIM....I'm sure ## wiring gremlins aren't anywhere near as bad as mine though...and why did Terry stop helping me

[selmerguy]

Check the big fuses under the hood. I bet you nuked one when your safc grounded out.

[Talon ESI-T]

Xmasta sorry, kinda lost track of your post on 2GNT. I have been getting numerous calls that suck up all my time. Not everyone is as easy to work with as Sam...lol


At any rate, check more fuses and check the fuses under the dash. There are so many possabilities and explanations available that we would sit here all day discussing why certain fuses could be blown. Instead just check them anyway.

the fact that everyting just quit indicatyes the car did not die of lack of fuel. This is a common way the ECU dies.

Terry

[DSMcrazy3]

I checked every fuse, they're all good.

[XMasta19]

Just like I'm doing...I would suggest ripping apart all of the damn loom in there and opening up that wiring harness. I only found two real spots where it burned through the loom from egr, but bunches of wires melted and shorted etc. I've got almost my entire wiring harness exposed now, and that's really the only way to do this. It's alright Terry, so when are you available to fly up here and fix my car hahahaha.

[DSMcrazy3]

I don't get why I'm still being told to check the harness near the EGR?

I understand that the EGR pipe easily burns through whatever touches it, but I've already checked along it thouroughly and found nothing harmed. Except for the ground wire to the SAFC, but that's taken care of.

[XMasta19]

I'm just sayin josh, my egr barely even got through the loom, and I found melted spots and crazy shit. meh, gotta get back to work

[Talon ESI-T]

Ok try this angle. There is a white wire with a red stripe at the fuel pump relay. Check that wire for a ground with the relay removed and when the key is turned on. The wire will only have ground for a few secs. If you dont have a ground then the ECU is not turning the fuel pump relay on. If you do get a ground and still no fuel pump power then replaced the relay.

Next, check for 12v+ at the center wire of the Coil pack. No 12v+ indicates no power from the ASD relay. Check the ASD relay circuit. The ECu sends groun to the relay to turn it on. Check that as well.

Terry

[dsmdan83]

Your car should start even with the wires unplugged from the egr valve solenoid. I have had similar problems before; one time car shut off and I was testing out my new hahn kit. I thought I ran out of gas, filled up.. checked all the sensors.. fuses...ect..( I really did not want to pay for a tow). Well after being stranded for a couple of hours I had my car towed to my house ( $60 bux). Popped the hood and inspected the fuses again and just happen to notice the big (engine) fuse was fried. Replaced it, everything was normal( except the feeling of wasting $60 bux).... Second time I was driving normally and my car shut off. I pulled off the road popped the hood checked the engine fuse and it was good. Stunned to find no problems. Some gave me a ride to my house (only 2 minutes away); got in my jeep, bought a tow rope from TSC and had a friend steer the eclipse while I pulled my car home. Checked every sensor and relay with multi-meter. Everything was fine so I bought a ECU and it fired right up.

[DSMcrazy3]

Was yours a 95? Those ECU's are known to have problems letting the car die, and eventually just crapping out.

[dsmdan83]

1999 eclipse rs

[XMasta19]

http://forums.2gnt.com/dcboard.php?a...d=98514&page=2


don't make me call you tomorrow Terry...I'll actually have some time to dig into some more wires....I better get this damn car running

[Talon ESI-T]

Most ECU's go out like that. If you test for the 5v and 9v reference you will find that many times when the ECU goes bad, it will stop outputting those voltages to the cam/crank.



X, let me look into your problem a bit, roll it around in my head, its been a long time since i was in the shop and dealing with problems like yours and Mike Homan's. In the mean time when you have time on your hands, make sure the ECU has 12v at all of its feed wires (it has multiple), make sure its has ground on all its ground wires. Make sure the 5v and 9v are at the cam sensor (i thought you already checked that part though).

Do you have access to a datalogger that will show cam and crank signal? Not the wave patterns but at least a yes/no field?

Terry

[DSMcrazy3]

Well I did alittle work today. I jumped the ASD relay and checked for voltage at the coil plug where I had 12v. Then I jumped the FP relay too, and tried to crank the car, it cranked but still never fired.

I pulled the #1 spark plug and checked for spark(with the ASD still jumped) there was none. I did the same with the #3 plug, and again, none.

I checked the Cam Sensor plug for the 5v and 9v signal, both wires had a whopping 0.6v. Does this lead to ECU failure? I read that if it read 5v and 9v that the ECU was outputting sensor voltage, but since mine is reading 0.6v I assume that means the ECU is not outputting voltage properly, no?

[Talon ESI-T]

Sorry Josh but that is an ECU failure. That is exactly what mine did when it failed in my 96 talon.

Terry

[DSMcrazy3]

Originally Posted by Talon ESI-T

Sorry Josh but that is an ECU failure. That is exactly what mine did when it failed in my 96 talon.

Terry

Sorry? Hell, I'm glad I have a straight answer and don't have to go searching through all of my wiring harness for a short or anything.

One thing I'm a bit confused on still is my SAFC was reading throttle position wrong.(I would have it at 100%, but the SAFC would read maybe 2%) I was told ECU failure shouldn't cause that, is this true?

[DSMcrazy3]

Got a new ECU today(used) and put her on and she fired right up.

It's from a neon though, so I have a few codes but nothing to worry about. I'm just going to use this one until I get a remanufactured one from the dealer

Thanks again everyone