So i have my 95 all done but i cant seem to get it to idle properly. It has a 318 and auto trans, it is running on a 360 pcm. At first it wouldnt idle at all and i found the IAC to be at fault so i put a new one in today. Now it will idle but it bounces around a bit and wont idle for more than a minute. If i give it gas and let off the throttle quickly it stalls instead of returning to idle. And on top of all of that when i try to put it in gear it stalls. I am leaning towards the TPS. Also my throttle cable broke on me so it is currently running via paracord. lol.

Anyone else have some input for me? im at my witts end with this project and am about ready to sell it for $1000 if i can get it.

Its hard to get started as well, it will turn over fast like it should for about 3 sec and then it stops, then it turns slowly, and then fast again.

 

Starting form the bottom, check and make sure battery is good, and connections are all clean and tight.

Check TPS as this and IAC can cause idle isses. Other possibility could be vacuum leak.

And the the paracord? lol....necessity is the mother of invention.

 

all connections are tight and its been staying on the charger. I replaced the IAC today and it helped but did not cure the issue. If the TPS is bad could it be causing it to stall putting it in gear? whats the proper test procedure for the TPS? also i am not getting a check engine light...

 

I test TPS by removing and using an ohmmeter. It should vary smoothly while turning. ANy dead spot along the way or erratic reading indicates that the potentiometer (TPS is a potentiomenter) is defective. Also check for correct voltage to it. I thnk it is 5v but not certain. FSM should indicate voltage required.

 

I'm with ya on the TPS, but I'd just get a new one to quickly rule it. Napa, for me, was like $30 ish. Also, the paracord is in connection with the TPS is it not? The TPS is quite sensitive and so that cord is adversely impacting it. So the order would be getting that cable remedied first, followed by TPS in the event symptoms persist.

Just to be sure, but I'm confident you did this, is disconnecting the battery prior to IAC changeout. Remembering to turn headlights on to fully discharge the system.

 

Here is something else that probably isn't the cause but is good to know for a no-idle condition. Air in the cooling system - what you say, "air", yes air. If a pocket of air is trapped at the sensor and the PCM can't get an accurate reading it will cause idle issues. I know this only after t/s the same idle issue you are having and throwing parts at it. I had recently done the plenum at that time and thought I would burp it for the heck of it. This even though I had already burped the mess out of it. Well, to make a long story somewhat shorter, air was coming out and when I was done my idle issue was gone. Don't ask me the specifics of what exactly the PCM was doing that would be a long drawn out explanation, but suffice to say it fixed my issue.

 

I am going to the junkyard today to get a new throttle cable and tps, I saw what appearrd to be a new on there last week. I have the paracord tie to the throttle where the stock throttle cable attaches, only so I could try to keep it running to put in gear. Battery was disconnected for 5 days prior to installing the iac and not reconnected till done.

 

Ramzy, this could be the issue as well since the cooling sytstem was completely drained prior to installing the motor. I have since filled it up and burped it but maybe not enough.

Also how sensitive are the tps, iac, and map sensor to water? It just dawned on me that I have 2 more throttle bodies with all the fixins on them, but they have been sitting outside for a couple of weeks and have been rained on twice.

 

Also how do I uninstall and reinstall the throttle cable?

 

Ive got the old cable out but I cant seem to find a replacement at the junkyard. It appears that the cable design changed in 96.