jns

I searched for some clues to see why my idle is rough but I don't have quite the same symptoms. It's been like this for a while but now that it's getting so hot here in Vegas, my idle drops to 400-500 (when in gear) and the A/C doesn't seem to work at that low of revs.

First off, I have no hesitation when I'm above idle. The engine will rev fine while driving. When I start it up in the morning, it idles at 800-900 and the engine shakes a little like it has a miss. With the A/C on, it idles at about 1100. The choke never works and the truck always starts up at idle speed. When I put it in gear, it goes from 1100rpms to about 500 and a pretty rough idle. When I lift my foot off the brake slightly, the truck jerks/surges/shakes (my 4 year old son thinks it's funny) and when I step on the gas, it has fairly good power and no misses that I can feel.

The stock ND plugs are 2 weeks old and properly gapped. The OEM Toyota wires are two years old. The coil checked out fine. I just replaced the distributor with a rebuild since the pick-up coil was at 285 ohms. Replacing it had no effect. I also changed the cap and rotor with OEM. I just adjusted the TPS with the correct feeler gauges. It passed smog three months ago with very low emissions readings. I have a new fuel filter,air filter and PCV valve (what a pain that was). I sprayed a whole can of engine starting fluid around the engine but no idle increase. I ran some sea-foam in the engine before I changed the plugs.

I'm considering the igniter but don't know if it could be that if the engine revs fine. Don't think it's the O2 since it passed smog easily. I'm wondering why the idle drops from 1100 to 400-500 when in gear like it can't take a load, why there is no choke operation, why it seems to stumble and miss at idle but no stumbling while driving.

Anyone else have this problem? Would a bad injector(s) cause these symptoms? Would the AFM cause this at idle only? Thanks for any info!

snap-on

sounds like the TPS needs a check up.

poorly performaning injectors could also be part of the cause.

KempLN3R

Try Cleaning the Throttle Body, Intake Plenum, AND the EGR intake tube. The amount of crap built up there always surprizes me! Take them off use parts cleaner, carb cleaner, degreaser what ever works.

I am not sure Seafoam is cleaning anything but the combustion chamber. There are a lot of people using it and getting improvements in performance but they need to keep the junk from getting into the air intake to begin with too.

Adding an Oil Catch Can that collects water vapor and oil off the EGR system will keep the intake area clean.

rdharper

Try disconnecting the TPS, ignore the check code, try a test drive.

jns

Great info. I never thought about a clogged EGR tube. I better let the fittings soak with some Blaster and check it out tomorrow. Thanks. Any another ideas if this doesn't work?

Glina

disconnecting TPS worked for me - try this!