G'day Everyone,

I am hoping to found that given history and symptoms, someone will be able to steer me in the right direction in rectifying the infamous code 42. I have spent hours on this and other forums, and it appears that although this should be an EST problem, other faults can set the code as well. The 'Vette is an 88.

The 'Vette ran fine until one hot start when it totally flooded: took a lot of effort to get it going, and I limped it the short distance home, stinking of gas all the way. I bought an SPX OTC 3498 scanner, as it had the TPI in it's database, but it would not acknowedge having been connected to the DLC. Hmmm....ECM problem? This is a while ago, but I spent a fair bit of time on the net, and all I read suggested that the ECM was the problem, so I popped in a remanufactured unit from either Eckler's or Centrals and hey, she runs again, but not for long. The SES is now constanly on, and sets immediately after startup even after disconnecting the battery. Once again, the scanner does not know that it has been connected, so I just jumped pins A and B on the DLC to find code 42. She starts first time, everytime, but does need a little help to get the idle to be reasonably steady.

The only symptom that I am experiencing is a marked reluctance to increase RPM: it's simply rough as guts, like the timing is out, but then this is supposed to be an EST fault, isn't it? The vehicle is not yet registered, so I am confined to working this one out off the road.

Can anyone help? I am all ears!

Many thanks,

Tony.

 

First, why did it flood ? Second, If it flooded that bad, it could foul the spark plugs. It could also foul the O2 sensor. Both will make it run bad. I'd have a look at both. Third, make sure there is no gas in the oil.

 

Thanks for your reply Jack,

As replacing the ECM cured the flooding, and it hasn't flooded since, I say it was probably a bung ECM. The flooding was basically a one-off event.

I take your point about the plugs and O2 sensor, but would either set code 42?

There's no gas in the oil. I changed it a while back, and it was fine.

Cheers,

Tony.

 

The most common reason for getting an error code 42 is because the EST connector was opened to set the timing. The ECM remembers that code and will show it to you for a very long time afterward even though nothing is wrong. I suggest resetting the ECM and then rechecking for error codes.

It's possible that your EST connector is open... ;-)

You might have problems with the wiring associated with the EST connector.

 

G'day Cliff, and thank you for your thoughts.

She ran just fine initially, and the timing has not been touched since. I have also had the battery disconnected on a number of occasions, so the ECM should have cleared any pre-existing codes. I have checked the EST connector and gave it a good clean with contact cleaner just to be sure, but then, it's just a connector, so point taken regards checking the wiring associated with it.

Bummer.........out with the wiring diagrams

Thanks mate,

Tony.