Alfa Romeo Forums banner

1 - 20 of 70 Posts

·
Registered
Joined
·
106 Posts
Discussion Starter #1
I have been unable to find a thread about removing and replacing the entire wire bundle running from the 1989 Spider Veloce ECU through the firewall into engine compartment and to the injectors / coil. For no readily visual reason my #2 fuel injector wire cooked and damaged the harness going all the way back to the relay. I have a replacement harness, have the carpet up and the glove box out. I know there is another wire hold down deep in the dash but want tips on passing the harness through the firewall. Do I want to go from engine compartment with ECU plug first and work it back to ward rear ECU or wire bundle with injector plugs up and wires wrapped up and fed under dash and pass through firewall to engine compartment? Thanks for all your help and suggestions.

Mick Nigel Dax
 

Attachments

·
Premium Member
Joined
·
900 Posts
Hi Nigel

Unless you figure out what went wrong with your old harness you're going to fry the new one, just as quickly.

Have you measured the resistance of the problem injector compared to the other ones? Is it shorted internally?

Bye
 

·
Premium Member
Joined
·
900 Posts
What was wrong with the old injector?

Hi Nigel

Unless you figure out what went wrong with your old harness you're going to fry the new one, just as quickly.

Have you measured the resistance of the problem injector compared to the other ones? Is it shorted internally?

Bye
 

·
Administrator
Joined
·
17,247 Posts
I agree that you should do some diagnosis to try to find out why it happened (so it doesn't happen again) .

As for your question, there is a metal/rubber grommet sort of item in the firewall. The metal halves come apart to release the rubber grommet and expose an elongated hole in the firewall sufficient to pass the wire harness components through. IIRC, I started in the ****pit side and fed the wire harness through that way. But it was years ago so I could be wrong. If the ECU plug does not fit through the opening in the firewall then it must be as I remember it. (but don't trust my memory as actually remembering things correctly...)
 

·
Registered
Joined
·
106 Posts
Discussion Starter #5
That was my concern immediately. Couldn't be the relay, none of the other wires burned but the #2 injector was the only unknown quantity. How do I measure with it in the car? I was going to use a jumper wire from the relay to the injector once I installed the new harness. The most burn damage is very close to the injector then works its way back. Then is substantial again near the relay.
 

·
Premium Member
Joined
·
1,598 Posts
From the looks of it, the problem was a cross-short in the wires near the #2 injector. Probably exposed conductors near the plug housing due to repeated bending/flexing or an isolated high heat episode.

If all you have is a couple of melted wires, I would simply splice a new plug onto the end of the #2 FI line (using butt connectors coated with shrink tubing) and replace, in the same manner, sections of any other wires where heat from the high amperage flow of this incident has cause the insulation to melt away and expose the conductors.

Employ un-insulated butt connectors for use with size #16 wire and use #16 wire to replace any of the destroyed circuit wiring. Get an assortment of heat shrink tubing (1.0mm to 10mm) and use a heat gun, a mini torch, or a hair dryer to shrink it. The heat shrink tubing will shrink to half it's original size.

A much quicker and easier fix than replacing the entire harness. And if my theory about the short being due to exposed conductors at the #2 FI plug, the problem is diagnosed and corrected.
 

·
Registered
Joined
·
106 Posts
Discussion Starter #7
Thank you. I found too much collateral damage inside the casing of wires running front to back from the one red #2 F/I power wire and short of cutting open the entire length of partially melted casing to inspect and miss one wire I run too big a risk for a repeat. Besides I don't want to leave behind a hacked up looking harness. I have another good harness but will isolate the circuit with a jumper wire until I am sure I have an injector that isn't defective or peri feral short. For now I'll figure out one way or another to get the harnesses through the firewall and routed.
 

·
Registered
Joined
·
106 Posts
Discussion Starter #8
WIre harness saga continues

So I picked up a great harness for my car. I am labeling all of the connections so the new one can go in easily. I got to the farthest wires from the ECU going toward the VVT solenoid and where mine looks to be hardwired, the harness I have has a pretty stout plug on the very end. I have a 1989 so I contacted the seller to find out what year his wire harness is from. Would be a bummer if I couldn't use it or had to do major surgery on it.
 

·
Registered
Joined
·
106 Posts
Discussion Starter #9
New issue

I figured out big plug on the end goes overr to the MAF on the intake. BUT the wire coming from the ECU harness has a plug with four wires and a single spade inside. The harness going to the VVT is the three prong style with three wires. How could this be? New harness came from a spider with no VVT or?
 

Attachments

·
Registered
Joined
·
106 Posts
Discussion Starter #10
This is the set of wires normally occupied by the set that connects to the VVT wire harness. Four grey wires with a green stripe.z the small black one is a black wire with agreem stripe. Don't know how to connect this to my 89 VVT wire harness? The seller said it came from an '87 spider. Mine' an 89.
 

Attachments

·
Registered
Joined
·
106 Posts
Discussion Starter #11 (Edited)
Maybe "The Godfather" Papajam has seen this. . . .

I can't edit the title it seems. This little four wire plug coming out of the F/I harness where the Three wire three spade plug is supposed to be is baffling both me and the seller of the harness. (Which I suspect is s dismantler and not from his personal S3. Has anyone seen this setup or is there a way to graft it on to my plug if it is a VVT connection? *Help*

Mick "Nigel Dax" Ferreira
 

·
Administrator
Joined
·
17,247 Posts
What do you want the title to say?

Do you have copies of Papajam's color coded wire diragrams? If not you need them. They would likely answer your questions. I can't help much because our Spider is an '84 with centrifugal VVT (not solenoid operated).

IIRC, there is a connection for a green/black (or black/green?) wire under the dash - behind the glove box. Is that present on your car?
 

·
Premium Member
Joined
·
900 Posts
Motronic or L-Jet

Hi Nigel
You have said your car is a 1989. Sometimes a car's title year and production year are different.

A 1990 production year spider would have had Motronic fuel injection. The 1990 car was a hybrid car it had the series 3 body but a Motoronic engine. The 1991 to 1994 car had Motronic engines and the series 4 body.

Does your car have electric radiator fans or a fan driven off the water pump? Does your car have a toothed wheel (60-2) on the crank pulley?

If your car has a toothed wheel on the crankshaft then it is a Motronic car and the wiring harness from the 1987 car isn't going to work. If no toothed pulley then you car is Jetronic and the 1989 harness should work.

Can you post an overhead shot of the entire engine bay?

Bye for now
 

·
Registered
Joined
·
106 Posts
Discussion Starter #14
Overhead engine shot. . .

I have L-jet. I have the white VVT and three wire connection. My old wire harness connects up fine, the replacement has this four grey wires with a green stripe into a single spade connector where the original harness's VVT connector is.
 

Attachments

·
Registered
Joined
·
106 Posts
Discussion Starter #15
I win the award. I have a wire harness no one can figure out what Alfa It goes to. But I know now. Anybody have a guess? Merry Christmas. ISIL has American Humvees but no Alfa Romeos. Italians win!
 

·
Trained (ex)Professional, , 1953-2018 RIP,
Joined
·
16,232 Posts
Eric's memory isn't as bad as he thinks. The connectors shown in post #10 are labeled by Alfa as connector G121. G121 is located under the dash behind the glovebox.
So the next question is, where is the 3-wire VVT connector?
 

·
Registered
Joined
·
106 Posts
Discussion Starter #17
It looks to be an un-altered harness save for the four into one combo where the VVT plug should be.
 

·
Registered
Joined
·
106 Posts
Discussion Starter #18
Aloha, there are no connectors coming out of the harness mid point that would connect to anything under the dash. Those connectors in post#10 sit inline right where the VVT connector should be. The second wire which I thought would connect to the inline fuse does not fit / connect to the inline fuse. Further I have discovered the five wires at the end where they connect to the coil / ground there are only two with a second ground wire weakly spliced and wrapped to another ground wire. Me thinks this wire harness has to go back. But I am still curious as to what model Alfa the harness DOES go to.
 

·
Premium Member
Joined
·
900 Posts
Non electrical VVT

Hi Nigel

Maybe your replacement harness came from a 1982 to 1984 L-Jet spider with the Mechanical VVT. That VVT was controlled by oil pressure and didn't have any electrical connectors.

Bye
 

·
Registered
Joined
·
106 Posts
Discussion Starter #20
Milano Guy wins the award!Upon further digging, I find out that the seller of the harness took it out of a 1987 Quad. However it ORIGINALLY came out of a 1982 spider that had mechanical VVT thus no connection for electronic VVT. the '87 Quad ran without the VVT connected. He indicated he has the correct harness for my car and will exchange it for me. This is luck only I have. If it isn't the mystery of one wire burning for no reason and ruining the harness to getting an incorrect harness that no one can figure out is how I roll. . .Thanks Milano Guy for your help!
 
1 - 20 of 70 Posts
Top