1994 4.3 CPI Chevy Blazer with a block out of a 91-92

Tiny
EL_GALINDO2004
  • MEMBER
  • 1994 CHEVROLET BLAZER
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 18,000 MILES
I had no choice at the time but to install a 91-92 block in a 1994 4.3 CPI model, which does not come out of a code 43 problem, causing it to idle a bit rough and knocks under a load. The 94 did not come with an ESC modual so I think this why it sets a code 43. I beleive the ECM it is looking for the modual. It first threw a code 42 until I found the 2nd knock sensor which was not connected at the time. One of the Knock sensor on the 91-92 is located on drivers side close to the fire wall(the other is on the side of the block, drvrs side too). The harness for the 94 indicates it to be on the passanger side. Non the less I replaced it with a new one made the pig tail longer to reach and connected it, erased and re-read the codes and 43 was set. So the ECM recognized the new Knock sensor once it was installed, but did not get pass code 43. My main Q is can a modual be wired into the 94 harnes and install a 91-92 prom to clear this code? Or can the ECM be fooled some how.
Do you
have the same problem?
Yes
No
Friday, December 28th, 2007 AT 8:38 PM

5 Replies

Tiny
MERLIN2021
  • EXPERT
Here's what I came up with on the 43 code, check all....even the 02. Is the new engine a cfi? if not maybe you should swap the intakes....


http://www.2carpros.com/forum/automotive_pictures/62217_43_1.jpg

Was this
answer
helpful?
Yes
No
Saturday, December 29th, 2007 AT 8:02 AM
Tiny
EL_GALINDO2004
  • MEMBER
This block was in a 89 model with a TBI System. Mine is CPI (central Port Injection) System not CFI. Also was not able to open up the caption underneath your comments. Do you have a link to that? Also the O2 sensor is new. Any other tips would help.

Russ
Was this
answer
helpful?
Yes
No
Saturday, December 29th, 2007 AT 10:38 AM
Tiny
MERLIN2021
  • EXPERT
What makes the most sense to me is swap the intakes, then you can have the CPI it came with, and all should work out.
Was this
answer
helpful?
Yes
No
Saturday, December 29th, 2007 AT 11:42 PM
Tiny
EL_GALINDO2004
  • MEMBER
First off thanks for the tips. Well the block I installed came from a TBI sys. I put it into my CPI sys. Can a CPI sys. Be turned into a TBI sys. At this point I have it for sale. So I need a good sales point. Thanks again

russ
Was this
answer
helpful?
Yes
No
Wednesday, January 2nd, 2008 AT 2:15 PM
Tiny
MERLIN2021
  • EXPERT
I don't know if the ports in the heads match up, Call chevy service, they may be able to tell you, or the local machine shop. Worse comes to worse, change the heads, if yours are OK.
Was this
answer
helpful?
Yes
No
-1
Thursday, January 3rd, 2008 AT 2:56 AM

Please login or register to post a reply.

Recommended Guides