spoazzy1

Ok I have a 305 TBI, and was having major issues with my idle running high and almost seemed as though it would stick. We pulled the throttle body, gave it a full overhaul using a new gasket and o-ring kit. I also replaced the IAC because it was super gunked. The only thing that has t been replaced is the TPS. Now it will crank up strong, and run great, but if you let it idle, it will drop rpms and just die. Is it possible that I have fried my TPS? We tried to get a reading off of it with the voltmeter, but We weren't able to get anything. I'm at a loss. On the bright side she's running fantastic, until it stalls. 🤔 I'm stumped now and am willing to take any ideas!!!

"John"

Sometimes what will happen to me. If I see my RPMs dropping I give it some gas and that usually does the trick.

spoazzy1

I have tried that, it doesn't work. I have to pretty much use two feet at a stop. One on the gas and one on the brake to keep it from dying on me. I'm at a loss!! I was idling way too high last week and now too low, I can't make sense of it now?

Bob88GTA

iTrader: (2)

Your IAC or IAC circuit is messed up or bad. IAC should keep the car running if operational.

spoazzy1

I just put a new one on it, the old one was causing intermittent stalling issues. I'm beginning to think my connector may need to be replaced. It looks like it's a little melted on one side. What's the easiest way to replace that? Splice and solder, then seal the splice?

spoazzy1

I think I have determined part of the issue, I never did adjust the new IAC. I've never replaced one and did not realize it was needed! I read on the tech board about how to do it, but do not understand the connector that I need to install a jumper on, where would I find this and what does it look like? I'm stumped 😳

Ron U.S.M.C.

Setting the timing =
Disconnect the EST wire, start car and idle until the car is at operating temp., adjust timing, shut off car , reconnect EST wire.


Setting minimum idle speed and resetting the IACV .=

• 1) Jump the A to B terminal under the dash with a paper clip
• 2) Turn the key on but do not start it
• 3) What 45 seconds (you should hear a slight ticking coming from the IACV valve) then unplug the IACV with the ignition still on.
  Disconnect the EST wire and remove the jumper.
• 4) Start the car.
• 5) It may be necessary to hold the throttle open slightly to prevent the engine from stalling.
• 6) Allow the engine to reach normal operating temperature.
• 7) Connect a tachometer. I used a digital timing gun with RPM feature.
  8) Adjust the minimum idle speed using the throttle stop screw.
  9) My Chilton’s says set it to 700rpm in park on an 89 TBI 5.0 auto.
  10) When done shut the car off and reconnect the EST wire.
• 11) Plug the IACV back in.
• Your done

Some paperclips come with a very thin plastic cover. Its hard to see unless you really look. Scrape it off.