I've been having tons-o-trouble getting my TBI system working. I've changed over to the 7747 ECU and I've had absolutely no luck at all with this stuff. My other post, Interesting Problem..., gives more details into the specifics of the problems that I'm having. Can anyone give me a small list of things to try before I give up on EFI forever? I've been trying to fix this problem for multiple months now and I've just got to have my car back, whether it's fuel injected or otherwise.

-Mark W.
'88 SC Camaro w/ 305 TBI

 

How's your IAC??? Is it stuck or broken?? that may be causing a vacuum leak and hence your rich condidtions. What about the wires that lead to the Injectors??? Is one ofthem bare and grounding out one o you injectors and causing it to be open all the time??? I'm just taking a WAG here so don't knock me I'm just trying to rule out things yu have done.

"Once you rule out the impossible, whatever is left, however improbable, must be the solution" -Sherlock Holmes

That's also the method I use to work on cars. Hope this helps.

Later,
Lars

 

Neither of the injectors seems to be wide open all the time. I've got an SES light with no codes thrown, and an apparent "limp-home mode" condition. The IAC is OK as far as I can tell, I don't think that would cause this condition anyway...not knocking here .

-Mark W.
'88 SC Camaro w/ 305 TBI

 

Sounds familiar: "I've got an SES light with no codes thrown, and an apparent "limp-home mode" condition." I've had that same problem (still get it every once in a great while) when I firsted started using my ZIF-socketed memcal. Some of the ZIF socket pins weren't soldered on good enough, and the socket wasn't allowing the memcal to clip into the ECM all the way due to its length and interference with one of the side clips. When it's not connected good enough, the computer does the same exact thing. I've been able to temporarily "fix" it on the road by banging on the underside of the dash to jiggle the ECM around a little. Sometimes that doesn't work, so I have to pull the ECM down and remount the memcal into it...

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Greg Westphal
'87 IROC 305TPI/A4

 

It's so strange, I don't know wtf's up with it. TBI ECUs don't have the whole mem-cal deal with the PROMs (they're just a chip that snaps inside a plastic carrier) so I didn't have to do any soldering type stuff to mine. I sorta think the PROMs are being read, 'cause when you scan it with the scan tool it reads the correct PROM ID number. The plastic carrier is certainly seated all the way down into the slot and the PROM appears to be properly seated in the carrier. I dunno, it's crazy bizzare. I think I'm gonna go get one of the original ECUs (I've swapped to a 7747, traded the original in for it) 'cause the original actually let the car run, it just didn't do right with quick throttle openings. Then if it works, it's something with the ECU swap...if it doesn't then I'll know it's something else entirely (scary thought).

-Mark W.
'88 SC Camaro w/ 305 TBI