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You really need a trained mechanic, or a family member/friend/neighbor who has some basic skills to work with you as you develop your own. But I guess that’s what Rennlist is for sometimes, LOL!
With that said, remove the brass retaining clips from the connectors, gently pull them off, swap them from one amp to the other.
Did you accidentally tear the left boot while pulling on it, or was it like that. If it was like that inspect the wires.
ETA I can’t remember, but you may need to take out the two bolts from each amp in order to get the clips off. I know that makes it easier to reinstall them.
Order some thermal compound, I used Arctic brand that I bought on Amazon. You will need it to properly reinstall the amps back on to the heat sink that they are bolted to when this project eventually resolves.
to get the amps off the board, remove the screws
work a razor blade under the edge all the way around,
work slowly so you dont bend the cover while the insides stay stuck to the plate
DO NOT ***REMOVE*** the spring retainers on the connectors!!! Don’t ever remove any retainer from a connector.
Use a pick to push one side slightly away from the connector, as you do that pull that side of the connector away from the amp just a bit. Repeat for the other side and then you can complete the disconnection. Do the same for the other amp.
Then unbolt the carrier plate for the amps. Disconnect the amps as I described. Flip the carrier plate over. Rotate the plugs and plug them in.
Then do your spark check. You can only run the engine for a few (~4-5) minutes this way. The plate will get hot and will need to cool or you can cool it.
Maybe it’s best to leave the amps bolted down for now. Removing the amps starts yet another project of cleaning the back of them and the heat sink, there is dried thermal paste stuck to all of them, and then you have to replace that paste with new material. Try to just remove the brass clips (or somehow move them aside without them flying off) using a tiny screwdriver or whatever you have and then swap the connectors.
Maybe it’s best to leave the amps bolted down for now. Removing the amps starts yet another project of cleaning the back of them and the heat sink, there is dried thermal paste stuck to all of them, and then you have to replace that paste with new material.
Right. This is why you do a swap of the connectors. If you actually swap the amps and it's not the problem you've created extra work.
Try to just remove the brass clips (or somehow move them aside without them flying off) using a tiny screwdriver or whatever you have and then swap the connectors.
Those retainers are designed to be *retained* in the connector. They don't just *fly* off. If they do fly off, it's because someone, previously, did remove them. Some of those retainers (e.g. injectors) cannot be re-inserted into the connector without re-melting the plastic of the connector. The c-shaped clips (these coil amps, knock sensors, etc.) can be removed and inserted if you are careful but they are devilishly hard to re-install correctly.
Never mind how easy it is to loose them or how easy it is to break the connector housing.
I keep a rod of minuscule-diameter spring steel so that I can 'make' these retainers when I have to. That tells you how often I find them missing.
H3ll: part of the OP's problem - maybe the whole problem - is that he doesn't have a retaining clip on the #8 injector. So, once the car's warm it's loose and disengages or provides a high-resistance connection and doesn't fire every time it gets a pulse.
Right. This is why you do a swap of the connectors. If you actually swap the amps and it's not the problem you've created extra work.
Those retainers are designed to be *retained* in the connector. They don't just *fly* off. If they do fly off, it's because someone, previously, did remove them. Some of those retainers (e.g. injectors) cannot be re-inserted into the connector without re-melting the plastic of the connector. The c-shaped clips (these coil amps, knock sensors, etc.) can be removed and inserted if you are careful but they are devilishly hard to re-install correctly.
Never mind how easy it is to loose them or how easy it is to break the connector housing.
I keep a rod of minuscule-diameter spring steel so that I can 'make' these retainers when I have to. That tells you how often I find them missing.
H3ll: part of the OP's problem - maybe the whole problem - is that he doesn't have a retaining clip on the #8 injector. So, once the car's warm it's loose and disengages or provides a high-resistance connection and doesn't fire every time it gets a pulse.
And yes: BTDT. (See reference to spring steel.)
Well I suppose it is possible that the one previous owner of the ‘87 S4, that I’ve owned for 25 years now, previously removed every single one of these non removable clips from my car, except the ones on the injectors, but it’s really unlikely. Perhaps they varied by model year, mine are removable.
If you somehow turn out to be correct in that the #8 injector connector is missing a retaining clip, I am going to be so freaking impressed! I mean that.
If you somehow turn out to be correct in that the #8 injector connector is missing a retaining clip, I am going to be so freaking impressed! I mean that.
It wasn't a prediction. It was just one possibility.
Even if the retaining clip is missing it doesn't always follow that the injector is intermittent.
If the amp swap and coil swap don't yield fruit, diagnosis of the OPs problem is going to get a lot more complicated.
Originally Posted by Shark2626
Well I suppose it is possible that the one previous owner of the ‘87 S4, that I’ve owned for 25 years now, previously removed every single one of these non removable clips from my car, except the ones on the injectors, but it’s really unlikely. Perhaps they varied by model year, mine are removable.
I didn't write that they were non-removable. I wrote that they don't just "fly off." You can remove them. It just isn't a great idea to do so nor is it particularly easy.
The c-shaped retainers take some doing to get off and twice as much to get back on. It's a three-hand job. Next time you have a junk LH or light harness lying around try it and see.
The few times I've found missing 'c retainers' the plug body was also broken.
On the other hand, a lot of '87-93s I see have had every retainer on the injectors pulled off and then, in some cases, 'sort of' put back in to 'sort of' keep the plug in place. From the factory a nub of the connector body plastic is melted over the middle of the retainer. So when you pull those out, they don't go back unless you get out your soldering iron and 'mush' some of the connector plastic over the retainer.
I have no idea why your 928 has all of it's c-shaped retainer clips missing. But, they didn't just 'fly off.'
Those retainers actually have a part number. Or you can make your own.
Then do your spark check. You can only run the engine for a few (~4-5) minutes this way. The plate will get hot and will need to cool or you can cool it.
Correction to the above. The base of the heat sink plate isn't in contact with the chassis. There is an air gap. So, you can run the car for a while with the plate unbolted.
Well ultimately I decided I better leave this issue to the professionals. Fortunately I have a 928 expert nearby (Brad M at Digital Chassis in Durham, NC). Just dropped it off.
Well ultimately I decided I better leave this issue to the professionals. Fortunately I have a 928 expert nearby (Brad M at Digital Chassis in Durham, NC). Just dropped it off.
06-01-2020, 11:30 AM
