problems with stock ecm considering swapping to xfi

[boosted]

Ok so my stock harness has a problem. Possibly a pinched wire or something in it. I could drive the car and it would just shut down. Whether it be hitting a bump in the road or taking a curve or when ever it took the notion. I would loose the scanmaster and the car woudnt start. I could grab the harness and move all the wires till i see the scanmaster start reading again, then the car would start. Due to that reason I parked it. Getting to dangerous to drive and the constant worry of when it would take a notion to quit. Now i've got the car tore down so i can paint and lighten the car a little bit I was thinking now is the time i can address this situation since i can get to everything. I was wondering about fast. Could I delete the stock harness and if so how much other wiring would it require to make the other things work(fuel pump, dash lights etc)or would it be more beneficial to pull the stock harness all the way out of the car and try to trace the problem out. My car wont see that much track duty. It'll see plenty of street duty though

 

[boosted]

I should mention that i was grabbing the harness under the dash and moving it till i seen the scanmaster light back up

 

[rag231]

I wouldnt have taken anything out until I narrowed the problem down to the bad wire and corrected it. You may take the whole factory harness out and still not find the problem. There are only a few wires running to the scanmaster and I would begin there. Triple check your grounds ,especially on multiple ground areas. I wasn't paying attention and pulled a wire out of the terminal using a ratchet to tighten a ground bolt once before, a few strands were barely touching metal. My check enging light would just flicker really fast and the car would shut off, so I know what you mean. Deleting the stock harness may be more trouble that what it's worth. Sure you will be getting a newer harness and deleting 25+ year old wires, but at what cost. Caspers make some really good wire harness components and this is their "light" version of the dash harness for basic functions if you do decide to go that direction.

http://www.casperselectronics.com/store2/product_info.php?products_id=1181


Then from the XFI you will be using the other adapter : http://www.casperselectronics.com/store2/product_info.php?products_id=1107

PS call Hartline for all of your XFI needs when you get to that point including your wiring harness needs. I hope my .02 helps you in any way.

 

[TurboBob]

its not the scanmaster wiring, its more likely the ignition feed wire to the ECM. Changing to another style of ecm is not going to fix your harness.

B

 

[davelostmissing]

Have you checked the more common issues- water damage at the ECM connector etc?

 

[we4Mateo]

My car acted the same. Ended up being the wiring coming down from the column. Like Bob said, ignition wiring won't be fixed by a new ecm.

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[boosted]

All that area is dry and no water or any moisture damage.I was thinking the same thing as Bob. Im thinking its the power wire going to the ecm since i can grab the harness right above the computer and jiggle it till i hear the fuel pump prime again and see the scan master come back on. I just dreaded taking the harness or the dash out just to trace one wire and if i was going to go that far should I just replace it with xfi and its harness(es)

 

[norbs]

YOu probably dont need to go to the fast XFI, but I really don;t think its going to hurt your performance, just check your pins if they are bad in the connectors at the ecm...

 

[TurboBob]

generally on a street car, the xfi is going to use an adapter and plug into your stock harness.

I would start wiggling things gently and see if you can find the sensitive spot. also consult the factory service manual for the routing and details of the harness and connectors to check that feed the ECM.

Do you have a voltmeter or test light to go searching with?

Bob

 

[salvageV6]

Check this connector with the foam on it behind the glove box door.

Pink wire with black stripe fat on one side thinner on the other, it powers the ECM and other sensors so wiggle that wire first.

Mine is already bypassed in the photo and the plastic loom goes to my GEN II so ignore that it's the connector behind that in the photo.

 

[GNVenom]

Here is an extreme version of water damage to an ECM connector. I have seen this many times over the years. Even the slightest sign of corrosion is a bad sign. Doesn't take much to lose the signal though.