Jetronic connector

Eep · 07-18-2008, 06:44 AM

Hi, new member here. I'm working on a '90 GT. Several of the wires entering the connector that hooks to the LH Jetronic box seem to have intermittent connectivity with their socket on the opposite face (the fuel pump lead in particular has a very bad connection and usually won't allow you to start the car unless you jump the relay). I wanted to remove each wire individually and re-solder or otherwise address the connections, but I haven't been able to figure out how to release them. I removed the pink plastic bar from the side of the connector, which looked like it might release them, but no dice. Do I need a special tool to reach down in the hole of each wire? Do I need to push them through? Do I need to pull with more force (I gave the wires what I thought were decent tugs but I was being careful not to break anything)? Any suggestions would be appreciated. Thanks!

Danglerb · 07-18-2008, 09:32 AM

Eagleday.com might have something, they sell the individual connectors. Lisle also make a set of pin release tools that might work, amazon.com has those.

Have you checked the connections on the Central Electric panel (aka relay panel)?

Eep · 07-18-2008, 11:22 AM

I will look into those sites, thanks for the leads.

I'm jumping into the middle of someone else's diagnostic work and he (my boss) claims that this is a well known problem with the solder connecting the wire to the port corroding and that he has found at least 10 broken/high resistance connections on this car. I don't know which two points he was testing, but I checked from the connector port to the relay for the connector pins I know, which isn't many. Most I checked were fine, but the fuel pump pin for sure showed a broken connection from the port side, but touching what I could reach of the crimp on the wire inside the opened connector I got a very solid connection to the relay. So it seems pretty clear that for at least the fuel pump, the connection between the wire and the connector port is at fault. It should be easy to check the rest and see if there are any other problems in the connector itself.

Thanks!

Danglerb · 07-18-2008, 02:22 PM

I've only been messing with these cars a couple years, but I've never heard of problems with the connections at the brains, only the relay panel. Relay XXIV controls the fuel pumps. Input to relay XXIV comes from (I think, didn't trace all the way) the ignition switch for the positive voltage, and the LH brain for the ground. LH pin 20 to CE panel connector W15, to pin 85 on the relay. Relay pin 87 is the output and goes to CE panel connector U25 (and V11 O2 sensor heater).

I don't see how you can try electrical work on a 928 without the shop manual and electrical diagrams. Check the Jim Morehouse thread on how to get some on CD.

Eep · 07-18-2008, 04:31 PM

I do have the full 7 volume shop manual, and have found some excellent general diagnostic procedures online that have been very helpful. If the manual (or the internet for that matter) mentions how to remove the individual wires from the connector, I haven't found that section yet. I am 100% positive that the problem is at the connection between the wire and the receptacle on the LH connector because I get a perfect, hard tone from my continuity tester between the metal crimped to the wire inside the connector and pin 85 on the relay, but I don't get a tone from sticking the probe where the pin from the Jetronic box should go.

If you believe my boss, this problem is fairly common in Houston because of our humid and occasionally corrosive atmosphere.

Following your leads I reached a place called Sir Tools that specializes in tools for German cars. They have a wire terminal extractor that may do the trick http://www.brandsplace.com/0384-sirst9025.html
I've e-mailed them to see if it will pull these specific terminals. Thanks again!

Danglerb · 07-18-2008, 08:02 PM

There are at least three guys who know the connectors VERY well that post here, but it may take a day or so before they drop in for a visit. Lisle sells a set that "looks" like much of the same stuff if not more, cheaper. Eagleday sell the connectors and a crimper at least. This is what I bought from amazon;

"Lisle 13120 Electrical Separator Connector" $7.76

"Lisle 14900 Wire Terminal Tool and Trouble Code Tool" $8.04

"Lisle 56500 Wire Term. Tool **" $8.94

BTW care to mention which shop in Houston?

Eep · 07-19-2008, 09:12 AM

Ahhh, excellent, I hadn't found those specific Lisle tools. I would love to hear from the guys that are experts on this stuff if they happen by this thread.

And I don't work for a shop, I'm just trying to get one of the company cars running.

We're actually a small engineering firm that likes to DIY when we can. My boss has a lot of knowledge of the cars because he has two (the company car and a 1982 he's lent to me for some TLC... more on that one later for sure) and he has ties to Porsche and some of the engineers that designed them. That doesn't mean he's always right, but it looks like he was this time.

Danglerb · 07-19-2008, 11:30 AM

I've been wondering if anybody was using a 928 as a company car, ah sweet deductibility.

If you want a connector to practice with, some Volvo's used the same 25 pin in the late 80's, about $35 from a typical boneyard.

Eep · 07-21-2008, 12:36 PM

That sounds like a really good idea, especially if someone doesn't thoroughly convince me that their tool will remove the pins with no problem.

And yeah, the company car stable is one of the perks of having a motorhead for a boss. Our other two company cars are a 2001 911 Turbo with GT2 turbos and GT3 suspension and an Audi RS6.

John Speake · 07-22-2008, 03:38 AM

You can buy sets of universal pin removers. The 35way connector sockets on the cable form plug have a small slot at the side of the socket, and that is where the tool is inserted.

The sockets you ned are identical to the ones used in the Amp Junior timer connector sets. These are used on all the two and three pin connectors in the engine bay.

I agree with Danglerb that those socket very rarely corrode. They are phosphor bronze plated. But the pins on the LH ECU do rot very easily. This is because they are steel, plated. Once the plating goes, they quickly turn to iron oxide :-)

The usual cause of rot in there is a blocked heater box drain, above the ECUs. The water runs down the LH cable and into the connector.

Have you inspected the pins on the LH ?

Danglerb · 07-23-2008, 08:54 AM

I had a chance to test my Lisle tool on a harness yesterday and the red star tool with the screwdriver blade has a thin rectangular blade that is a perfect fit to release the pins on the brain connector.

Lisle 14900 Wire Terminal Tool and Trouble Code Tool

Eep · 07-24-2008, 09:12 PM

Mr. Speake:
I haven't looked at the pins on the LH itself (beyond a cursory visual inspection for bent or corroded pins). If there has been water in the area, I saw no evidence of it, and we did at one point switch out the LH box for a known good box with no effect. I won't rule it out, and I certainly defer to your experience, but I would like to address the sockets that I know are bad, so thanks very much to you and Danglerb for the information about how to do so. Hopefully I can get my hands on some of these tools and give them a try in coming week.

Thanks to both of you, and I'll keep you posted!

John Speake · 07-25-2008, 12:43 AM

OK Good luck ! Keep us informed, it's always useful to know how these things end up. Adds to the common pot of knowledge. We are all learning.

Just call me John :-)

Eep · 08-25-2008, 09:06 AM

Okay, finally have time to look at this again. Danglerb, you said that the screwdriver tip on the tool released the pins--so what is the technique you used? I had played around in the openings on the side with a screwdriver and had no luck, but I was being fairly careful not to break things. Do I push aside the metal flap partially covering the opening? Do I push it in? Do I slide it past the flap and push on something else? Or maybe I stick it down along the wire? Thanks for any help!

Danglerb · 08-25-2008, 09:55 AM

Quote:

Originally Posted by Eep

Okay, finally have time to look at this again. Danglerb, you said that the screwdriver tip on the tool released the pins--so what is the technique you used? I had played around in the openings on the side with a screwdriver and had no luck, but I was being fairly careful not to break things. Do I push aside the metal flap partially covering the opening? Do I push it in? Do I slide it past the flap and push on something else? Or maybe I stick it down along the wire? Thanks for any help!

Thats a negative on the "use a screwdriver", the Lisle 1400 tool that "has a screw driver" has a narrow rectangular blade that fits into the release slot on the pin side of the connector. Round shaft of a tiny screwdriver or a wire I think is less likely to release the pin.

Eep · 08-25-2008, 10:00 AM

Ahhh, good, yes, I somehow misread that. So glad I asked before I went after it hardcore. I have some errands to run at lunch so I'll pick up the tool and give it a whirl.

Danglerb · 08-25-2008, 10:09 AM

Once you have the 1400 tool you will see one blade is a perfect fit for the slot next to each pin, on the pin side of the connector. Its a small groove in the plastic body.

If you can't find the tool, what I might try is a slightly larger wire squished on two side in a vice or something, but I suspect the size is critical in getting a smooth release of the pins.

Eep · 06-20-2009, 11:38 AM

Just wanted to give an update on this particular project. We finally decided my boss was nuts because every symptom matched a bad LH box exactly, so we found a repair shop willing to loan us a box and sure enough, it fired right up and runs beautifully, so we'll be ordering a re-build from them. And no longer listening to a thing my boss says...

Next up is a shift linkage re-build!

And replacing a few gaskets...

And addressing that rattle in the clutch...

And getting the peeling front fascia repainted...

And...