Hi, I'm new to the site. However, My car is brand new as well...er, sort of.

I drive a '87 IROC. I just got it about a month ago. Already it has new liquids and a new tranny in it. WHile I've had it, I've noticed a knock or a ping that occurs around the 2500-3300 RPM range while under heavy load. It builds up too, as it goes on. Once I let up off the pedal, it goes away. It does not do this while in park nor does it do it when driving on the street. Does it mainly when trying to get on the freeway. Recently, the engine light comes on after this, and stays on untill the car has been shut off for at least 5-10 mins.

Supposedly, it's a 350 with .040 over bore, however, I've not had the chance to confirm this yet.

Any info would be a great help and I hope to come to enjoy this site.

 

Start by reading the error codes. Bend a paper clip in half and put it in the 2 upper r/h holes in the diag connector located in the drivers side hush panel just above your right knee, there is a little door there you need to remove.
Turn the key to on, the light will flash code 12 ( one long flash and 2 short flashes) three times then any stored codes 3 times each, then code 12 again.

post back here what the codes are.

 

Well, the only code that showed up was 43, and that was after 3 tries. So, would that explain my problem?

In any case, the engine now makes a funny noise that sounds like a cricket. It's sorta loud, and gets louder as gas is fed into the engine.

Also, I forgot to mention, the engine was supposedly swapped. The VIN indicates the 5.0 305 being the original motor, but the previous owner said that he swapped it out for the 350. My question is, if they didn't change the ECM out, would it be causing this problem.

Again, rookie rambling on, appreciating any help given.

 

Code 43 is a bad esc module or a bad knock sensor. Check the connector on the knock sensor, make sure it's not disconnected or burned thru.

 

You didn't say what kind of intake system you have. If it's TPI you would need to change the PROM with the engine swap in order to get the fuel mixture right. A stock 305 uses 19lb./hr injectors, while a 350 uses 22lb./hr

 

It's a TPI.

 

Sounds like the knock sensor is working but the ECM cannot adjust the timing. check the base timing then look into the ESC module. also it may be as simple as the fuel you are using