Schump

Hello all,
My faithful truck, Sluggo the Mule seems to have a cold or some such ailment.
(He just rolled over 156k out of 500k planned. ~14k of which was 4 trips cross country, VA to Mammoth, CA and back twice....taught skiing in Mammoth Feb 2003 till broken leg on the clock and a DUI 3 days later...WHAT a week!, KILLER '03-'04 season w/ 120+ days skied, and last '04-'05 till I broke the same leg on the same mountain. Pavement is harder than snow. Shattered femur, cracked pelvis-motorcycle-cutoff into corner...ugh!)

A while ago, I did a tuneup and replaced the cap, rotor, plugs, put 2 cans of AMSoil Power Foam through the intake, replaced the fuel filter, cleaned my K&N cone, and then it ran worse! Handy paperclip pointed me to a dying ignition module, $1x10^6 from the dealer, $50 at the junkyard. Though the junkyard part may have headed south, paperclipped the 2 plugs and no trouble codes are flashing. Truck will usually start fine when cold, but trouble when hot. It'll turn over plenty fast and if it doesn't fire right after it starts cranking, it'll usually fire after the engine cranks for 5 or more seconds and the starter seems to hit max velocity. Twice I've had to use starter fluid recently. I set my advance back from 14 degrees to the factory 10, but I think I'll turn it back up to 14 because it made more power and otherwise ran the same.
Also, i'm still having the idle problem. Again, when hot. In the morning, he idles around 900 rpm or so. After the truck warms up, however, usually it drops to only 150 rpm or so, and gets lumpy (who wouldn't run lumpy @ 150?) from 250 to 150 and back and forth. I usually keep my toe on the gas at lights to keep the idle up. Sometimes it will come to rest around 450rpm idle, other times it'll be really low, I'll blip the throttle a few times, and it will go from barely running (~150rpm) back to 500rpm.
of note: I somehow pulled the hose off the fuel pressure regulator a while back that goes to the hard line on the front of the motor, the short rubber connector. The other 2 hoses next to it are still tightly attached and won't budge, but now the hose isn't "locked" in place. I did put a zip tie around it and it should be sealed, but perhaps I should grab 6" of hose from the shop first and see if this is the problem?
Shoot, maybe I just answered my own question... Maybe not.
If it matters I'm usually only getting 15-16mpg, but I got 17.2 when I drove from DC to Carlisle last weekend for the import/kit car show.
Thanks for the help, sorry for being long winded...never should've taken typing in high school!
Haynes manual says to check fuel tank vent, anyone had a clogged vent cause poor hot starts?...i'm still eying that hose!

TNRabbit

I'm guessing you might have a sticking throttle body. That's what it sounds like. Carbon/oil residue from the PCV valve builds up and doesn't allow it to close all the way. This affects your idle, then you adjust with the idle screw and it's all over the place. That's where I'd look FIRST (easy to fix, if that's not it you're not out any $$$).

Schump

i'll try that first. i posted here a while ago, i think i figure out my thermo time switch, or whatever the 2nd thermostat is called that controls the cold start injector is dead. my coil was also dead, got a used one at a junkyard in woodbridge for $50 instead of the $230 or more that the dealer wanted for the ignition unit on the side of the coil. i'll have to read all of what i posted months ago. i did the paper clip trick, no trouble codes on my check engine light.
wierd thing is, when he's hot, he might fire right when i first hit the key, if not, i gotta wait a while (sometimes like 10 seconds) for him to come to life. tonight in the CVS parking lot he was being stubborn and i almost got it to fire then i just listened to the starter for too long. a hottie was getting in her car and asked if i neeed a jump...hmmm...to look at your *ss when hook up the cables...hmmm, let me think about that for a while...(ok, i'm the mechanic, i hooked em up, but she looked yummy
after i got a "jump"...don't think i needed one, it was turning over plenty fast enough) i added more starter fluid through the K&N. no dice, still spinning...
ok, ripped the k&n offf, threw it in the bed (i have the full K&N intake system, traded my OEM airbox, etc and a drop in K&N and a six pack for the setup with a friend, he was a mechanic who got it from a customer.....v6 w/ 1 rod through block)
so i pushed the MAF open with my finger and filled it with ether. bada bing bada bang, i had to get them to close my hood for me cause when hot it has a lumpy LOW idle...50-150 or so. sometimes, if i blip it to 3k a few times, it'll settle on 500 rpm, but it's like 900 when cold. i will try cleaning the throttle out w/ carb cleaner tomorrow night and if that doesn't do it, get a thermo switch #2 through work (i work at a VW/audi shop so i can get parts from our wholesalers, schwing!...think the dealer wants like $130 or so for a damned 1 wire sensor..wtf?)
i'll also look through the posted online complete dealer manual.
anyone think it could be a clogged gas tank vent like Haynes suggests? and if I pull off my gas cap, won't that tell me if the vent is clogged or not? from the pic it looks like the vent goes to the filler neck, i didn't see a nipple that vents to the atmosphere in the drawing...i'lll have to crawl under him to check unless someone knows.
thankx

TNRabbit

Do you have a leak in your intake? (before the throttle body)

Schump

good ?...I'll check, i guess w/ starter fluid sprayed around the seals, if it revs up yes. is that the best way to check (i'll use my ear but i think the fan noise will be louder than the leak noise.)
could this cause the really low when it wants to be lumpy idle too?
time to get working on him, at least i don't have to work today...
thanks.

Schump

no leaks found. rubber boot that attaches to throttle body is a bit dry rotted on the outside right next to the hose clamp that attaches it to the K&N plastic intake tube, but after inspecting i couldn't find any that went all the way through. now, my idle screw was set at only 1.5 turns out. I added another turn out to raise idle. I started it, idle was good, turned off, started again, hoo ahh (don't cheer yet...) blipped the throttle a few times. got one backfire.
previously, i got a hella backfire. i tried opening the throttle w/ my hand and huge flame shot out the throttle, blowing the intake boot off. scared the crap out of me. i do not believe i had the hose clamp tightened yet.
i did use carb & choke cleaner to clean the black crap out of the TB as far as my finger could reach. perhaps it was holding the butterfly open a tiny bit, i dunno.
now my truck is STILL laughing at me. turned it off, tried to restart, i just get to listen to the starter and motor spin. 1st and 2nd time, it made a hint like it might want to start, but didn't quite catch.
i changed the coil to the one i got with the junkyard ignition box, no difference. (engine not thowing any codes now.)
now Sluggo is just sitting in my driveway keeping me from going to the Bug Out....argh!!!
help!
i would think that turning the advance back to 10 degrees wouldn't keep it from starting, but i don't know (originally 14, had more power, will readjust when i get the mofo running...) back to the not so helpful haynes manual...no wait, there's that factory service manual online....thanx for that post, i'm gonna weed through it now....
thankx