[AllThumbs]

My car is an 84 LeBaron with the 2.2 Turbo.

This is an embarrassing question, but here goes: Where exactly is the ground on the "driver's rear corner of the block?" I see lots of references to it, but cannot find it. On the driver's side, there is a ground on the fender well, there is a ground on a bracket at the end of the valve cover, and there is a ground (maybe) to the neutral safety switch. I have the DSMs and look at the diagrams and schematics and all that, but it never says EXACTLY where this ground is, and I can't find it.

Is it something that can only be seen from underneath the car? Or maybe I'm missing that ground wire altogether. Which would certainly explain a lot...

Thanks.

David

 

[Bob Lincoln]

I know it's on the TBI engines, and I believe it's on the same place on the turbo engine. I can check mine in the morning.

If you look at the driver's side of the block (which is the 'end' or conventional rear of the block, left side of car), below the head about a couple of inches, there should be a 15mm bolt screwed into the block, which holds a large ring tongue terminal to it. This is the ground wire for the sensors (O2, MAP, TPS, AIS) that run off the harness that is routed along the rear of the valve cover. The view of the ground lug may be obscured by the turbo lines or the air cleaner box.

 

[AllThumbs]

Thank you. I will doublecheck, but I don't recall any wires running from that harness down to the block. There is a ground strap right next to the two sensors near the injectors, but it goes to the firewall, not the block. As I mentioned there is a thick (probably 6 ga) ground wire coming from the harnesses behind the battery that goes to the "rear" of the block, but in the front and on the very end of where the valve cover meets the head.

 

[Bob Lincoln]

I forgot to check my turbo this morning, will do it tonight. There is a ground from negative battery post to block, as you mention; another from negative battery post to left fenderwell; sensor ground as I described above; a braided strap from passenger side firewall to intake manifold; and a braided strap across the two halves of the passenger side engine mount (often missing, because a mechanic lost or broke it when changing a timing belt).

Check out this picture of my TBI engine, looking at the driver's side of the engine. Ignore the two red arrows, they are for something else. Note the bolt with the yellow-sleeved lug under it. That's the sensor ground that I'm talking about.

 

[AllThumbs]

Thanks again. I haven't seen the ground in the picture, but let me doublecheck, since in my engine it could be covered from view by the battery cable going back to the starter.

Roger on all the other grounds you mention, including the braid on the passenger side, which is a bit frayed but seems okay (In fact, I cleaned it on Sunday afternoon).

 

[AllThumbs]

I checked my engine last night. Nope, there is a bolt there, but no ground attached to it and no evidence that there ever was.

That said, maybe the wiring in my car is different somehow, since the DSM diagram shows that there is supposed to be a ground there, but NOT where I DO have a big 6ga ground wire from the negative post: it's the one attached to the bracket high on the end of the block.

I also noticed in the DSM, however, that that is the wiring the 2.6 is supposed to have (ground on that bracket, but no ground on lower block). All I can figure is that somehow over the years this car ended up with 2.6 wiring.

Any other ideas? I could add a ground wire to the lower block, but I'm not sure where I'd attach the other end of it.

 

[B10alia]

I can't imagine that the car would run properly with a 2.6 wiring harness. That ground in Bob's picture appears to be attached to the cylinder head, not the block. The block is cast iron and would be rusty if left unpainted like that; that sort of whitish appearance is how aluminum (head material) weathers. In the picture, the block is that dark brown line just below the ground location.

From what you're saying, it sounds like you have the ground wire coming all the way across the head to the threaded hole visible in Bob's picture at the radiator side of the head, just underneath the valve cover bol nearest the left red arrow. This should be OK. What matters is that the head is electrically bonded to ground, it doesn't matter where the ground wire actually goes. It sounds to me like someone may have mesed with the wirein

Don't add ground wires. You can create what are called ground loops, which result in electrical interference. This will make your computer very unhappy. If you think that there's a grounding issues, it's OK to replace ground wires, but simply adding more grounds could cause problems.

EDIT: With a little more thought, the wiring harness absolutely cannot be from a 2.6. The 2.6 was a carbureted engine. There would be nothing to drive even one fuel injector, let alone the four in a turbo 2.2.

 

[Bob Lincoln]

My bad. That IS the head and not the block where it's grounded in the picture.

And I looked at my turbo today. Like yours, the bolt is there, but no ground. So perhaps it relies on the braided ground strap from firewall to manifold for the sensor ground. If that is in question, make a new one.

 

[AllThumbs]

Thanks. I have looked at that, but it would not hurt to clean up the contacts and doublecheck.