schrade

Sounds great!

Let us know what the author says when you tell him he's wrong.

And if you're scared to call the number, or email them, or write them a letter, and tell them they're wrong, we'll understand that too.

anesthes

I'm not corvette folk, I just bought one because it was cheap at the time.

And don't take it personal, I'm just generalizing.

-- Joe

anesthes

There is no such input. I can post you all the ECM schematics if you like, as well as the source code to each BIN if you want to read it line by line.

What your suggesting is not impossible to design, it's simply just not there in stock form. I don't know WHY they didn't do it that way, because they had the hardware to do it.

Actually, that is not 100% correct. The ECM stores the last known BLM for the entire fuel map in NVRAM and continues to use those corrections until the 02 sensor becomes ready.

But that is besides the point.

-- Joe

anesthes

I don't think he offered to email them, but I will. I read corvette enthusiast and a few chevy mags and the editors always welcome corrections. I don't see why this would be any different.

-- Joe

schrade

That sounds like a good idea too. Who knows - the author, and the shop (IDA Automotive) might have found out differently since the article was written, and updated their tech info. And if you're the one to expose their error, that makes you the man!

But in the meantime, I've seen nothing that disproves it.

Benny42

The wiring diagram DOES mean something. I went out to my car and
unplugged the oil pressure switch (red and orange wires). It started
and ran fine. Unplugged the FP relay, no start. Reconnected oil
pressure switch, long crank, then start and run ok. benny

anesthes

Didn't we show you the diagrams and such from the FSM?

I mean, if where gonna question who to believe, shouldn't it be GM rather than an enthusiast editor?

-- Joe

anesthes

I emailed them:

----
Hello,


If you review the attached image of the Corvette Fever magazine, November 2000 issue page 21 you folks were involved in a tech article (image attached) regarding
fuel pumps and other things on the C4 Corvette written by "Ray Bohacz'"

Within the article your text suggests: "if oil pressure diminishes, it automatically shuts off the electric fuel pump" in regards to the oil pressure switch.

However, we feel this is an error. After reviewing the wiring diagrams and fuel pump operation in the FSM for various years of C4 (from 1986 - 1996), along with
field testing on these vehicles we understand that the oil pressure switch is simply a redundant fuel pump circuit. Our thoughts is the design of this is to keep the motorist from becoming stranded should the fuel pump relay fail.

If you look at the code in the ECM, and the schematic you will find that as long as the distributor is reporting reference pulses to the ECM, the ECM will continue to energize the fuel pump relay. Disconnecting the fuel pump relay will still allow the engine to start and run based on the oil pressure switch. (with a longer crank due to loss of the priming functionality). Disconnecting the oil pressure switch will still allow the engine to start and run as the fuel pump relay is energized by the ECM.

The reason we are bringing this up 8 years later, is because the article in question has been scanned and referenced on corvette websites as being factual data.
We feel it is important this information be cleared up to avoid future misunderstandings.

Thank you!

-- Joe
-----

MK 82

Didn't take it personally. Just makes you sound kind of pompous.

MK 82

If it's in print, it has to be correct. Right?

anesthes

That was the point really. I'm poking fun at a lot of these guys. I go to car shows and meet corvette owners, and they act all pompous with all their trivia, and how wonderful their car is, and no blemishes. Then they tell you how their "mechanic" did such a wonderful tuneup. I like throwing it back when I get a chance. Corvette owners tend to have oversize egos.

That's not to say there isn't just a huge bunch of great guys on here (PeteK, LD85, Joby, mseven, and so on) but then again I met all those guys on fbody forums years before I bought a corvette.

-- Joe