Surging Idle at start??? Hot or cold. HELP!

[jjdude]

I have spent a few hours now looking for a similar situation but no luck. So new post here goes. I have a 96 with 185K on the ticker. Recently it has developed a surging idle when I start it and has become much harder to start when cold. She used to fire right up, but always gave some good smoke for a minute or so. Two weeks ago I started the truck cold and it started surging, about 400-1000 rpm. If I rev it to 1000 rpm or so for a few seconds she drops down to about 500 rpm and comes up to 600 and sits fines. I don't feel any real power loss or big change in fuel consumption. I read in another post that unplugging the ICP while its surging may tell you if your sensor is bad. I fired the truck up and with it surging unplugged the icp. Smoothed right out. Replaced the sensor and still have the same problem. Used a ford part, no aftermarket. The problem happens with the truck cold or warm. The weather does not seem to matter ether. It's been everything from 60 to 0 out in the last few weeks here in Buffalo. Insane weather! There have been a few times it fired right up like it used to and runs fine, but I still get a good amount of smoke. No oil in the valley and the level is fine in the HPOP. I'm stumped! Where should I start?

[Patrick Feeley]

Next time, try starting it in neutral (I'm assuming an automatic here). Does it still do it? If it is smooth in neutral, you might try adjusting (or replacing) your Transmission Range Sensor. Cheers!

[jjdude]

Originally Posted by Patrick Feeley

Next time, try starting it in neutral (I'm assuming an automatic here). Does it still do it? If it is smooth in neutral, you might try adjusting (or replacing) your Transmission Range Sensor. Cheers!

Case closed! Cranks and runs perfect. I think that my range sensor is bad. I'm not an expert but I think that thing can really cause a slew of problems. I should have changed it a while ago. When I bought the truck last year the PO called the day I was supposed to pick it and said it would not start. I don't think he was very mechanical but told me they had to replace the solenoid on the fender. When I got the truck, I noticed it had not been changed and thought he was a jerking me around. I had some tranny issues (hard shifting, dropping out of gear, O/D light flashing, etc) so I crawled under the truck and saw that the sensor had been changed. I'm assuming to some autozone junk. After cleaning the connector with contact cleaner and adjusting all my tranny issues disappeared. Then I had the truck not crank for me. Put her in neutral and problem solved. Cleaned/adjusted it again and she fired right up. Every time I use/see aftermarket.....problems!!! Go OEM. I'll put up the outcome but I'm sure that's it. Thanks Pat!