sheepdawg58

ok so this truck is really being annoying. ive drove this truck about 350 miles so far but the past week it has been really cold (18-24 degrees in the morning) and the truck will not crank when its that cold. it will spin over plenty fast to crank but just not fire. i tried it this morning while hooked up to jumper cables and nothing. but over in the afternoon it will fire right up really easily. im at a loss for what could be causing it. it runs great once i get it cranked in the afternoon so i donno what to do.

sheepdawg58

okay so this truck is being really confusing. im starting to think it may have a bad crank positioning sensor or something like that. but its really getting anoying. i cranked it up and drove it bout 25 miles to the parts store this morning. about 5 miles from the house it started missing backfiring and running really bad. it did that for about half a mile and then cleared up like someone flipped a light switch.

i got to the parts store and bought one of their supposedly better scan tools to diagnose the problems with this truck and see if i can figure it out. i drove home and about 10 miles down the road it did the same thing... even acted like is shut off.. then fired up and drove on to the house.

i got home and hooked up the scan tool hoping to figure this thing out and everything to go smoothly, but should have known better. im not sure if i hooked up the OBD-II plug wrong or what. i connect the scan tool to the truck and turn the key on. the scan tool will power up but it wont "link with the system" to test i hooked it up to my 97 f350 and it didnt work right either. so i donno what i did wrong. all i know is im not gonna keep driving the truck till i can get it figured out and i spent 350 bucks on a scan tool that dont do anything for me. i hope i can get it warrantied out

just call me smithy

Did you turn the ignition to on? The scan tool will get power and be on when your ignition is on accessory but it won't read codes unless the ignition is in the ON position.

sheepdawg58

i tried it with the key off key to ACC key on and with the engine running. turned the scan tool off. then turned the key to the ON position and tried to get it to link... all it did was power up the scan tool.. it didnt link to the system

sheepdawg58

okay so just to update ive parked the truck for right now. from best i can figure without bein able to hook a scan tool up to the truck is the crank position sensor is acting up. i figured hmm that cant cost that much so ill just replace it. called a lil while ago 90 DOLLARS WHOA... so i gotta go back and make sure i wired up my OBD-II plug right. i cant spend that much on something that dont cure the problem. so im back to the wiring diagrams for now

hamish_18

Have you tested the CPS at all? There will be some troubleshooting stuff in the FSM. And make sure that the OBD-II scanner supports the ECU you have. 96-97 ecu's used I THINK the older GM protocol. It starts with a V I think? Any years after that, its the normal ISO protocol. Port is 2 grounds, a power wire with 10 amp fuse, and the signal wire. Mine isn't even shielded, and it works great. And make sure you have the right com port, and baud rate setup if the scanner doesn't auto detect it...

Just my 2 cents..

sheepdawg58

hmm... hamish you have succeded in confusing the crap out of me lol... i re wired my OBD-II plug correctly ( didnt have the power and ground wire right,, go figure). and my scan tool read it perfectly. i checked codes and only had 1 trans code at first. i fooled with the scanner some and figured out how to get it to work. then i noticed i had 2 codes... one for the trans and a P1600 ECM BATT MALFUNCTION. im not sure what that means.

i test drove the truck and go figure nothing happened. i kept the scan tool hooked up and on live mode so i could see the general workings of the engine, which is pretty cool.

im gonna drive the truck tomorrow to work and see if it acts up. im gonna keep the scan tool hooked up just in case.

vital22re

iTrader: (2)

the p1600 could be related to your wire mix up.

sheepdawg58

aight im gonna try to erase the codes and start again when i head to work in the morning... im very pleased with the added power of this engine. i guess im just working the bugs out of the system. i want to get this thing running reliably before i tear into the SAS... its kinda got me worried right now

sheepdawg58

aight well i drove it to work this morning... fired right up and drove to all the way to work without so much as a hickup... 38 miles. only had 3 codes on it. 2 for the trans and that same P1600 one. i found a write up on what that is and im gonna look at fixing that. it also drove all the way home without a problem. i think i scared it into acting right. but then again it was in the 70s today. ill update when i drive it in the rain and cold again.

hamish_18

go figure. You always have the problem, until you are ready for it to happen.

Sorry for confusing you. I just had an issue with mine because I didn't know any better that Toyota used two different OBD-2 protocols. My first scanner wouldn't work.

Hopefully it was some bad gas or something, and it never happens again...

sheepdawg58

haha... or hopefully im just workin the ghosts out of this engine... im gonna keep on foolin with it... thanks for all the help

Team420

Just curious... Have you done a compression test? I have seen motors with weak rings hard to start when cold...like say...outdoor temp is below 40*f, but when it gets into the 60's, and up, it fires right up no prob... will run like crap for a sec or 2, and then great for the rest of the day... In fact... there is a thread on here by me, I was trying to fig my bud's 93 runner hard start issue... went thru all sorts of stuff, had it running many times in my heated garage, but leave it outside overnight, and she wouldnt run till noon after it warmed out... I finally decided to run a compression test, and blammo... most cyl were at 30-60psi, and I had 2 at 180...

Hope this isnt ur problem... just sayin... I learned the hard way... when diagnosing... 1st do compression test, then move on from there....