negativematt

I finally got to the point of trying to fire my engine for the first time tonight. It spins over and I have spark at each plug and have fuel at each injector, but it just won't light off.....it will pop and blow smoke, but never gets lit. seems like a timing problem, but i'm not real sure.

I sent it off for a speed density tune with vats delete etc but I'm not sure what else is going on inside the pcm. I know it's a shot in the dark, but anybody have any ideas?

psiconversion

iTrader: (5)

Matt,

What is the engine from? 58X or 24X? Drive by Cable or Drive by Wire?

Jon
PSI

negativematt

To the best of my knowledge its an 01-03 truck engine, I got it from a friend and there were no sensors in when I got it, and to be honest, I didn't know much about the 58x 24x stuff. It has the blue/green plugs on the pcm and is DBW.

ls1nova71

iTrader: (4)

How do you KNOW it's getting fuel at each injector? Stuck injectors is a real common first start problem.

green96ta

iTrader: (11)

Matt,

Your engine is 24x and most likely is a 03 since DBW became most prevalent in 2003. Have you had the coil harnesses off recently? I ask because that is a common issue when coil harnesses have been removed and then subsequently installed backwards.

negativematt

They have been off and it is quite possible they are on the wrong bank...I'll swap them tomorrow and see what happens! I loosened the fuel rail and spun the engine over to make sure the injectors were firing.... I have the ingition switch out so I can crank the engine from under the "hood"....the entire front clip is off so there's not actually a hood!

green96ta

iTrader: (11)

Im not talking about just swapping banks. Check this out.

Every coil will have 4 wires. Every coil will have the 3 following colors.

Black- Ground
Pink- Ignition Power
Brown- Ignition Reference

Now the 4th color is what determines what connector goes to what coil. Check this out.

1- Violet
3- Light Blue
5- Dark Green
7- Red

2-Red
4-Dark Green
6- Light Blue
8- Violet

negativematt

I gotcha! I'll double check and make sure tomorrow....I really appreciate the help!

gofastwclass

iTrader: (2)

I know this sounds random but by the title of your topic I assume you are you a Metallica fan, correct?

jaybuller

TEST YOUR CAM SENSOR or replace. mine did the exact thing and i replaced the cam sensor and it fixed all my hard start/popping issues.

negativematt

HAHA...I'm a fan of Metallica before the "Black Album"....but yeah, I ripped off their tune....hope they don't sue me!!


My CAM SENSOR is brand new....I know that always don't mean anything, but I'll look into it!

Chevy406

iTrader: (12)

Are you sure that your coils and injectors are supplied by constant 12v at "key on" and "cranking"? Try giving it a shot of ether to see if it will fire up.

psiconversion

iTrader: (5)

Second waht 406 stated. You need to make sure that your KEY ON ignition wiring has power with KEY ON and CRANKING. This is a very common mistake.

Jon
PSI

negativematt

Damn you guys are good!! So here is what I found......I moved the coils down under the plugs (im running flipped headers for the turbo), but didn't think about that causing the coils to be feeding the wrong plugs!! ie...coil #1 was firing plug #7!!...and so on....got that problem fixed.

Now it's trying to fire, but my battery voltage at the coils is dropping to 8.5/9v no matter where I try to get power from. This is a 1949 Studebaker truck with an aftermarket wiring harness. I've run power direct from the battery to the fuse box and even ran a jumper from the ign switch to the battery to try to stabilize the voltage. I know my problem lies in this voltage issue now. I'm gonna let the battery sit on the charger for a bit and then give it another shot....if that doesn't work, then I'll break out the trusty Fluke and start checking wires!!

negativematt

Got it to 11v during crank and still nothing....if I just bump the key it will light off sometimes, but never take off....I know its close but dang!!

jaybuller

I still think cam sensor possibility. Don't know how you would test it but I would.

green96ta

iTrader: (11)

Glad to help on the coil issue!

Now onto the new gremlin,

MAKE SURE AND CHECK ALL GROUNDS!

Sorry for yelling. . Most of the time the "Low voltage" is actually a bad ground.

You should have a ground strap from battery to frame and from frame to engine.

negativematt

I have 4ga from the batt to frame, then another from the frame point to the block, then from block to body and body back to frame point...I'm pretty sure I got that issue covered! ....but I do appreciate the help! I know I'm close, I emailed the lt1swap guy who did my pcm...but he's slow to respond!

negativematt

UPDATE: I got it to fire and run....but only by spraying fuel into the intake....I've orderded a fuel pressure gauge to put at the intake to monitor the pressure. I've read that using the vette filter/regulator and the one built into the truck intake might cause an issue...any thoughts on that? I know we're close here...but I've only got 2 weeks before I head back to afghanistan and really wanted to hear this pile run on it's own!!