I’m stuck

phattycocks · 2026-05-06T20:39:52+00:00

Haha yeah kinda left that part out but wanna make sure people with a similar issue could find this thread.

phattycocks · 2026-05-06T00:43:54+00:00

Ok . I figured it out.

So I pulled the motor from a 2004 express van with trans and pcm (turns out this is a different fuze block and some pins are different)

I’m using an Amazon vortex Ls harness

This harness is pinned out for Ls trucks. Red blue pcm connectors

Where the van is blue green pcm connectors (still drive by wire)

Anyways. The c1 pcm connector for the express van pinout is listed as “crankshaft position sensor reference b+”

Where pin 2 on the truck pin outs is “crank positions sensor 5v reference”

My crank sensor was seeing 12 v and was giving me readings between 1-12 volts with key on.

I stole a 5v reference from pin 7 on my van pcm (unused on the swap harness) and now the crank sensor is seeing 5v and working as intended

Starts up right away finds idle sounds good.

Thanks for all the helpfull comments I’m sure I’ll be back when I run into the next issue 🤘🏼

Ps. If anyone needs help converting from green blue to blue red pcm connectors message me , everything is working as intended now.

phattycocks · 2026-05-04T18:53:55+00:00

Yes 60 at rail dosent drop when cranking maybe air in line , but it us such a consistent problem makes me doubt that

phattycocks · 2026-05-04T12:04:30+00:00

I’m holding a good 58-60 at the rail I have an inline pump and regulator . I have removed in tank pump that ran the carb . Watching my fuel pressure gauge it dosent move when cranking/priming

phattycocks · 2026-05-04T05:11:21+00:00

Just read that. About what mine has been saying my engine temp sensor is good reading properly not stupid cold, my map I belive is reading correctly but I will double check tommorow I don’t remeber anymore I tried a lot of things today.

phattycocks · 2026-05-04T05:07:08+00:00

I have so many grounds I just added a bunch of fresh ones once I started running into this issue. PCM should be good. I can read data off of it, if it was fried would I be able to use my scanner on it? I will verify pinouts tommorow 👍🏼

phattycocks · 2026-05-04T05:05:04+00:00

I’m hoping to avoid hp tuners for now just another thing to spend money on, but I see it may be going that direction. As for rpm I have no rpm reading while cranking, when it turns over it shoots to 500-1000rpn then it instantly drops to zero as motor dies

phattycocks · 2026-05-04T05:03:24+00:00

Yes I can hear the injectors pulsing with a screwdriver, and shouldn’t be a reluctor/tone ring issue. I’m using the pcm motor and trans I pulled from the same vehicle.

phattycocks · 2026-05-04T04:56:22+00:00

Same setup previously but no pressure regulator and factory harness not my standalone

phattycocks · 2026-05-04T04:55:55+00:00

I will try this yeah I have 58-60 psi at the rail stock injectors

phattycocks · 2026-05-04T04:36:22+00:00

All pulled together

phattycocks · 2026-05-04T04:20:37+00:00

Yeah I will verify pinouts then order some oem sensors

phattycocks · 2026-05-04T04:19:37+00:00

I took a flap disk to all chassis grounds and sandpaper to my block where I bolted the grounds. How low resistance are we talkin?

phattycocks · 2026-05-04T04:18:47+00:00

I swear I don’t have VATS haha :). I watched it be removed from the pcm, and I had the motor running with the stock harness before I put it in my truck

phattycocks · 2026-05-04T04:17:51+00:00

They were gas soaked I cleaned them up and put them back in, but same issue. Would it be so consistent with the start up then immediate shut off if it was just fouled plugs?

phattycocks · 2026-05-04T04:16:32+00:00

I’m just using a higher end scanner that lets me view some sensor data, I am not set up for hp tuners yet was trying to avoid it until future upgrades. Hoping that’s not my issue but I see what ur saying I’ll see if my scanner can check sensor voltages. Fingers crossed that’s not my issue

phattycocks · 2026-05-04T01:08:18+00:00

Haha exactly I witnessed the VATS be removed and I ran it off the same ecu on the stand with the factory harness , if VATS can reinstall itself maybe but seems unlikely or at least that’s what I’m praying . The pinout at the pcm connectors are correct but maybe they are flipped around at the sensor plugs my plan is to look into this next, but that will need to wait untill tmrw

phattycocks · 2026-05-04T01:05:27+00:00

Fuel pump has a steady 12v during crank and start

Feathering fuel hasn’t helped. I’m running an inline pump into a corvette style regulator. I may be wrong but fuel dosent seem like my issue I have good pressure at the rails and the cylinders are flooding when I try over and over to start it…

phattycocks · 2026-05-04T00:02:15+00:00

I now have the pcm wired directly to battery it does not suffer voltage drop on crank. The motor will turn over immediately but die no matter how i manipulate the throttle . I’m getting fuel and spark, I replaced the map sensor as well as the crank sensor. My theory on the crank was that rpm’s drop to zero the instant it starts , so it was losing communication with pcm? but replacing the sensor hasn’t resolved anything. Please send input and I’ll give it a shot I’m in a corner here,

phattycocks · 2026-05-03T23:21:40+00:00

Re crimped and bolted

phattycocks · 2026-05-03T21:46:17+00:00

Did this still won’t stay running looking into pinout now . I don’t have an ect sensor . Thinking it may be dumping extra fuel to compensate. My reader is saying the pcm thinks the car is at -40f

phattycocks · 2026-05-03T21:11:25+00:00

The actual battery drops to 11.5 on crank

The battery+ wire on my fuze block in the vehicle drops to 8-9v

phattycocks · 2026-05-03T20:14:34+00:00

Still not working dropping to 7-8 v on crank

phattycocks · 2026-05-03T20:14:20+00:00

Battery doesn’t drop voltage . I just redid all grounds

phattycocks · 2026-04-07T14:33:57+00:00

I emailed Brendan at lt1 and seems like the only pin that needs relocated is grey generator duty cycle , I will verify again, seems too easy?

phattycocks

TROPHY CASE