thats right....there is two sets of fuel injector grounds on the passenger side that attach to the cam boxes! Odd but it makes sense....no ground = no main injectors...which makes sense given the symptoms you were having of it firing off the cold start injector..which is on a different circuit...

Way to GO!!!!

 

Excellent, nice work, way to stick with it professionally, even with a broken and bolted leg.

I like good beer, but would like to substitute for something of equivalent value.

Say, sitting in passenger seat while you safely run $5 worth of hi-test gas through the supercharger.

 

YEA!!! IT LIVES!!!

 

YES!!!

 

Great news.

Wally P was on the right track.

Tails 1990 928S4 Auto

 

Great, now you can remove and return all those new parts you didn't need back to Roger for a refund!
New igntion switch
New fuel pump
New fuel filter
New ignition relay
New fuel pump relay
New temp II sensor
New thermo time switch
New cold start injector
Used Auxiliary air valve
New starter
New battery

Jk!

Do I understand correctly that you had put the injector harness grounds on the fuel rails? Why? In that case, you're grounding to the intake manifold. Those grounds are supposed to be on the block, right? I found that moving them off the block causes problems. Interestingly, I too had mine on my supercharger manifold briefly after my SC install and had no end of weird fuel injection problems until I moved them back to the block.

 

Ahhh, and there was also a little voice in an earlier post...

 

PARTY!!!!!!





+1

I don't have my car home to look at, I thought those grounds were supposed to attach to the cam tower where the plastic guard behind the cam gear attaches to.

 

On his shouldn't they be on the cam cover. Here's a (bad) picture of an 84.

 

YAYAYAYAYAYAYYAAY!

 

OK, I was thinking of S4s, like mine. I'm not sure about the 16 valve cars, but on S4's the FI harness grounds are at the back of the valley, right into the block, not the cam towers. In theory the cam towers should work. I just know that when I grounded to a bolt that went through my SC manifold into the head, I had problems. They were sporadic problems. Car ran fine for a while the started go very wacky fuel wise. Moved the grounds back to the stock location and never had those problems again.

Anyway, glad he found the source of the problem, although he almost rebuilt the entire car before he figured it out.

 

In retrospect, deeper drilling into "what have you done last" would have potentially helped.



The connection point, though the picture is lousy, is on the pass cam cover about 1/3 of the way back. The 82 is likely same as 84, though not sure.

 

I helped a friend swap a brand new harness $$$ into his S4. Only to find during installation those ground points you are talking about, loose. That was his problem all along. We installed the new harness anyway.