hey guys
have an 87 305 TPI,
Recently have changed
02 sensor, EGR valve checked vacuum lines, cleaned the IAC, and I continuing to have the same problem.
What happens is I start it up and it will start fine and run good for about a minute until it starts to idle down, it then begins to run rough and it smells rich and will chug and dies. What do I need to be checking?
thanks in advance
John

 

sounds like a typical vacuum leak. go back and recheck all your vacuum lines. with everything you have done, it leaves the potential for all sorts of them. i looked for two weeks to find a vacumm leak. i found it using carb cleaner. i've also heard you need to reset the computer and the iac as well as adjust minimum air settings when you have cleaned the throttle body.

 

thanks for the response
I did find one vacuum leak but it is still doing the same thing runs good for a minute idles down and runs like crap and dies. How would i reset computer or adjust the IAC? What are the symptoms of a bad IAC?
thanks

 

to reset the computer, just disconnect the battery cable for a few minutes.
there is a tech article on adjusting the minimum idle on the main page. or you should be able to find it with a search.

 

i was having the same problems with my TPI. thanks to a lot of reading and trying stuff i figured these out. check the minimum air idle, TPS sensor voltage and whatnot. check out these pages. have you checked codes at all yet? after you reset the IAC and adjust the TPS if you have to you need to reset the ECM and let it pick up from fresh

Tech Articles - Adjusting Your TPS

(this was the best explanation i found with pics and whatnot)

P.S. check the ohm reading on your injectors too while your out there with the multi meter

 

ok guys
Check into this a little more this weekend. Went ahead and started replacing vacuum hoses and found some pretty bad ones. Idles much better, Replaced TPS and put it within the correct specs. But it still seems i am having a little issue. When I first start it up it idles real low around 500 RPM, I give it gas and it bogs down and I can hear it popping a little through the intake? But after about a minute it comes out of it and it runs great I hit the gas and no hesitation and idle improves to around 700 or so. I haven't really driven this car in a few years is it possible the gas has gone a little sourer and maybe condensation is causing it to act up on startup? Recommendations on what to check next?
thanks
JJG

 

yeah, if the gas is old....it will cause problems. that wasn't mentioned before if the gas has been in the tank a couple of years, it could affect the performance of the engine.