x_streme

Howdy, need some opinions. I just replaced my head gasket, put MSD wires on and NGK plugs in. The next day it ran great. About 75 miles later, she started running extremely rich, cutting out, sputtering, and had a very rough idle. It threw me codes:

21
22
23
43
and
53

I replaced the O2 sensor and the plugs as they were carbon fouled...no change.
I replaced the TPS...no change.
It is intermittently retarding the timing at idle, drops it down to 6 deg. BTDC from 11deg. static, but not all the time.And now my fans have stopped working. The only idea I have left is the computer. Any words of wisdom?

TIA

x_streme

0h yeah, I forgot to tell you I also cleaned the IAC and TB with no results.

nobodyunknown

Did you clean the IAC before or after the 75 miles?
The IAC has to reset,usually after driving 45 miles an hour.It can be installed incorrectly,The pintle has to be fully withdrawn before installing or it may be damaged.
A test for the ECM is tapping on it while the engine is running,if the engine idle changes due to the tapping,the ecm is likely to be bad.
Static timing is when you set the timing with the engine not running.Do you mean with the computer unplugged?
If the IAC is not set properly it will make the idle vary which could make timing change.
:chevy

nobodyunknown

P.S. did you use sensor proof gasket sealer?
:chevy

x_streme

yeah, sorry, i did meen with the computer unplugged. i cleened the IAC after the 75 miles, but drove it this morning over 45mph, no change, i will try tapping the comp. thanks

richardb

my ecm went bad in my 86 and it did every thing yours did unplug the batt and clear the comp. hook it back up and start it if it runs good for a short ti me and goes to crap it is the ecm.

PeteL

Have you cleared the codes and see what re-sets? TPS is showing as both high and low, which is possible at different times. To narrow this down you need to see when the codes set.

Re-set start over and see what you get. Unplug the battery for a few minutes.