How do you know if your computer needs to be replaced?

I bought a 91 f150 w/ 5.0 v8 and the diagnostics complains about some of my brand new sensors but did not complain about the faulty ones that i replaced.

Also does the computer have anything to do with shifting gears? won't get above 20 mph but have not started diagnosing that yet.

thanks!

 

Usually it won't go into diagnostic. Depends on which transmission you have.

 

Remove the ECM and open the cover and look for anything burnt on the board. It's located under the driver side kick panel. There are places that rebuild them. I'm on my 3rd one on my 90... Call your Ford dealer with the vin and they should be able to tell you what trans you have. That could be vacuum shifted.


Edit.. Stupid question, I know, but did you reset the computer after you replaced the engine management parts?

 

Yep had it disconnected for the last 18 hours then repulled the codes. Now it is only complaining about 1 new sensor but also through code 998 (hard fault present) this time.

 

I think that's one of the bad computer codes.

 

With everything else that i have to replace that is not surprising. Thanks!

 

I had a computer go bad in my 87 f150 and when it initially happened I was going 70 down the hwy and i thought my motor blew...it would barely run or even start.

 

Have you taken a look at it yet?

 

Unfortunitly have not had a chance to yet, should be able to rip it out today.