I am at the tail end of my build. I have an 84 c10 2wd short box that received an lq4 6.0l heart transplant. I have a no start after having the truck running.

A bit about the build

2003 Lq4 with upgraded intake TBSS and ev6 injectors DBW
Dual in tank holley returnless regulated fuel pumps - both tanks get 58 psi to the rails. In line pressure guage confirms.
4l60e transmission
Psi harness 1258165 pcm from 2003 savana 6.0l - have two other pcms
New cam, crank and MAP sensor
No IAT - have factory 2 pin but need to add to harness

The truck ran on the initial start up, rough but it ran. Removed vats and emmisions and has not ran since.
Grounds are good - battery to close to starter 2 guage , front passenger head to chassis 1 guage, battery to body 12 guage
Get rpm when cranking ~150rpm
No burp, bump or fart from engine.
Have 12 volts to coils, scanner shows signal going out
No crank error codes, but after extended cranking get camshaft code
MAP shows .1 upon cranking 0 with key in ignition
All relays are good
In need of a new ignition switch in the column, but have 12 V tied into system through rocker switch. Key operates starter only. 12 volts to system while cranking.
Injectors work. Smell of fuel after prolinged startup attempt.

The base tune on the two other pcms I have gives P107 low circuit MAP code that will not clear. The current PCM gives no TPS signal, will try and reset, but not sure why it is not there, no tps will not result in no start

VCM scanner shows activity where it should be. In my opinion there is nothing preventing this system from firing.

I am missing something. What it is I do not know. Any fresh ideas or point towards a better base tune for this setup would be appreciated.

 

MAP shows .1 while cranking. .1 what?

 

I would flash the original tune back onto the ECU and see if the truck will start. Then only change one thing at a time to determine if you have a broken wire or something.

 

I recently went through the same thing with an LQ4 and Crank No Start. The final piece to resolve my situation was a bad Crank Position Sensor Wire and pig tail.. No check engine light but would throw the PO335 code as soon as I turned the key on. Audible (meter) tested the 3 wires to the CKP Sensor to find the Sending Circuit was culprit (took several times and different positions). Fuel pump worked, just was not turning on nor getting signal. This doesn't go without sharing I replaced Fuel Injectors + a bad injector pig tail (had all kinds of codes). I replaced the Crank Position sensor (only use GM) twice, and the PCM. My car sat for several years and when I pulled the PCM Harness, I found corrosion at the connection, took the PCM apart and found corrosion in the PCM too. So, I had a couple problems, but believe my crank position wire was what was giving me the main problem There were only 2 strands of wire still connected at the broken point.. This was beneath wire looms and electrical tape at a soldered repair years back. Solder joint got compromised and I had no way of knowing until I pulled it apart.

I almost consider it a fluke because, my car started and ran (old pcm) bad heads and wiring. I replaced my cylinder heads and in that process was when I screwed up the injector wire (crimped under a NOS line), obviously, the wiring was moved around, etc and it's all 20 years old. Time killed my PCM with corrosion (Car sat outside under a car port for 4 years). Luckily no rodents.....

Hope this helps.... mine was wiring as mentioned above....

 

Well, I'll tell you guys this. I got a c a i. Aluminum .. I bought some heatshield. And heat tape a trap that sucker I also put the sticky shield on the boxes the filter sits in. Just ran a test myself just now. Let my car idle for 20 minutes. Pop the hood touch the tube Not hot at all. After 20 minutes of idling So if you get the aluminum. Or the plastic just buy the sticky Shield. And wrap that sucker. All you heat problems will go away. Regardless of what you have

 

Aaand that relates to this thread HOW??

 

I had some dude do the same thing on a jeep forum the other day, posted on my for sale thread, basically babble just joined and spammed all over the site, then poof gone.............crazy, but so is the world

 

this right here, change one thing at a time, eliminate each item,

 

I'd wire up the IAT sensor, put a new set of plugs in it, see if it starts...

It's adding a **** ton of fuel since it thinks its -40 degrees outside.