My truck, Sluggo Thu Mule is...duh, quite stubborn. Usually, starts no worries when cold, sometimes have to give it a foot full o' gas for it to start hot. I did a fuel pressure test a few weeks ago. 40 psi w/ vacuum line attached to pressure regulator, but opposite of what Haynes manual said it should do with the vacuum line disconnected. It jumped up to 50psi. this makes sense to me though, WFO you have more air flow, so you're going to need more gas as well. Also, coming back to the shop on wednesday, it started fine and i left the restaurant parking lot. as soon as i got onto the street it felt like someone had stuffed 9 shop rags into the mass air sensor! it would NOT rev above 3000 rpm, and would stall if i let my foot off the gas. I got the same problem for the first time again this morning in front of our shop, but after revving it several times and it ran for a minute or so, it just magically went away. seems to me like a loose wire somewhere?
also, i disconnected my TPS and MAF sensors, and finally i got it to throw another code... the engine air temperature meter. can't find anything on it in the Haynes manual, i'll look at the factory one online.
I also need to adjust my TPS and the dashpot on the throttle body. 156,690 miles right now.
if it matters...
When i pulled up to the bank window to deposit my paycheck, idle had gone from 900 down to about 450-500 and was very lumpy, like a second hand on a watch...sounded like some big cockroach was jumping up and down on the gas pedal, it blipped about once every second. then after i got my $$$, the truck told me to F off, and it started running tily again. it stalled, busted out the trusty can of starter fluid (a healthy dose of ether seems to get it to start when it's in a bad mood and won't start when hot)
it did the same thing it did on wed...barely running but it wasn't quite so bad, but it would stall if i took my foot off the gas.
and when i parked in front of the shop, i let it sit and it cleared up, revved up like a champ, then all of a sudden, wouldn't go above 3,000 again. i noticed that when i floored it it took a nose dive, but if i gave it a little bit of gas, it would rev up (sounded and smelled like it was missing something fierce) up to maybe 3500. if i then put my foot in it, it would nearly die till i let off the gas.
(sorry this post is so long...i'm long winded!)
also, at times it seems the cold start injector is still on when hot...it runs bad and then i'll go and unplug the cold start injector and the idle will return to normal. i have already replaced the $130 thermo time switch which was bad.
thanks for the help,
Dave

 

Was it throwing any codes before you unplugged said devices?

 

no, i checked 2 weeks ago, no codes. i also read in the manual that the intake air temp is combined inside the MAF, so if that's actually bad, i'm FUBAR'd. but the codes were only thrown after I pulled both sensors while running (it died when i pulled the MAF plug)
also, i drove the shop car to look at housing and came back to the shop. truck started right up on teh street, i parked in front of the shop door. unlocked the shop, turned alarm off, hopped back into truck to bring it inside.....it wouldn't start. so i did what has at times worked in the past.
I unplugged the cold start injector, and WA LA!! click click vroooom.
WTF?
can something else besides the overpriced thermo time switch trigger the cold start injector to fire even when the motor is warmed up?
i'm going to measure TPS voltages now for good measure...
i've always loved my truck, but this is really waining on my patience!...and sure, i'd like a barely used taco, but damned if i want to sign myself up for montly payments for the next 5 years! besides, 156k is just broken in for a yota, right? (me hopes to get 500k out of him...eventually....