Project Underfunded / next phase - LSx carb'd to LSx efi

[jfortvalley]

just because it was the only wire terminated doesnt mean you shouldnt verify both (their both in the socket) takes 2 seconds with a dvom

[usmcchevy]

That is the way the fuel pump is suppose to act. Verify you have 12v at the injectors and make sure you can make a test light pulse when probing the injectors and cranking. If both of those check out, I would bet on clogged injectors.

[68GMCCustom]

the pump (-) is grounded to the frame. The lead coming from relay is +12v.
Don't have a test light...just a multi-meter. I'll check the injectors for +12v.

[gringoloco]

2-3 seconds when you turn the key to RUN or START? Pump should prime in key on (RUN) for a few secs then turn off. If it pumps for a few secs after starting then cuts off, you likely have a VATS issue. What wire did you use from the truck to power the fuel pump relay?

You can check for voltage at the injector plug with a noid light or DVM while cranking. Also, if they're working, when you pull a plug, you'll know it from the flooded cylinder. Could be a case of the common stuck LS injector. If so, soak 'em in SeaFoam to clean out the gummy ethanol deposits...

Good luck- keep us posted
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[mcbassin]

What did your fuel rails come from? was it used setup? Did you disassemble the rails from the intectors when you mounted the intake on the engine? Not that yours has the same problem but both of my rails were full of old gas and it would run until I cleaned all that gas out.

[68GMCCustom]

had dirty fuel that I flushed with new via draining at the schrader valve. Pump stops in run and start as motor never fires over yet don't hear the pump. Need to verify these injectors are firing and pushing fuel I guess

[68GMCCustom]

well I found a loose/unterminated connector, at the cam sensor. after that with a little more messing around on the fuel side I got it to start with some starter fluid. ran for a bit and quit. did the same thing a couple of times, each with the same result. tried to work the throttle once and it was like the TB didn't even get the message.... :lol

checking voltage at the injector showed 12v w/key on, then dropped a little while starter was active? If there's a "pulse" my multimeter can't catch it
sound like I have a VAT issue...or a bunch of bad injectors...or both.

[mcbassin]

I don't think a DMM will catch the voltage. You have to use a light if I'm not mistaken.

[68GMCCustom]

More I think about it...I'm guessing it needs a crank relearn. This ecm is new to the motor...and maybe they're just not in sync?

[mcbassin]

Originally Posted by 68GMCCustom

More I think about it...I'm guessing it needs a crank relearn. This ecm is new to the motor...and maybe they're just not in sync?

Any luck confirming you are getting fuel through the injectors? I'm wondering if you could disconnect the plug wires and crank it and see if you have any fuel on your plugs?

[usmcchevy]

Originally Posted by 68GMCCustom

More I think about it...I'm guessing it needs a crank relearn. This ecm is new to the motor...and maybe they're just not in sync?

It should still run without a relearn, you would just have a check engine light. Try cranking for a while and pull a plug, is it wet? I'm still betting on clogged injectors.
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[Lower]

I have a full set of injectors, if you need them let me know. Have you checked to make sure the plug next to the starter is plugged in? If you have any friends at a mechanics shop you could ask them to borrow their injector pulse tester.

[mcbassin]

Any news Kurt?

[68GMCCustom]

Had me do the security/crank relearn which didn't seem to help. I need to pull some things today and figure out whats going on...and they're supposed to call me back again today for support.

I need to order a trans too. Needed to sell some stuff 1st tho. Think I'll hit the wife up for some funds...

[mac72]

Kurt,You definitly need a noid light to test the pcm output & if you get a decent flash from all connectors I would get an OTC injector tester,Its a handy tool to own if you mess w/ injectors.Theres 2 versions one cheap & one expensive the cheap one will work fine for what your doing.How it works is you pressurize the fuel syst. by cycling the key,unplug the injector & plug in the tester,hook the other leads to the batt. & hit the button while monitoring the press. drop on your guage,this will tell give you a good flow/no flow diag. you can also compare it to other injectors for flow rate.Both of these tools are inexpensive,definitive & are good add. to the tool box

[68GMCCustom]

Well....I ordered my new "electronic" transmission for switching to efi. I understand the 6speed wasn't as good for "racing"...so I ordered 19156257...a GMPP 4L85e. Got a 1350 yoke for it too. New trans and yoke for my "well it was new when I put it in" 6.0L.

Funny thing after pulling the trigger................can't wait until it gets here now!

[chevytruckluver]

Hi Kurt, just getting up to date with your build again.
Any luck getting it started yet?
I have an older TPI that was acting the same way, would run if you sprayed some berryman's through it but when that ran out...nothing. (old injectors)
I ended up pulling the injectors and fuel rail off setting them off to the side and then pressurizing the rail with the pump and then using a 9 volt battery to fire the injectors, pulsing the power to each one several times. I had 3 that would do nothing and another 2 that dripped under pressure so I just got a new set, installed those and she fired up.

[68GMCCustom]

Hey Trey...nope not running but I haven't been working on it other then to install a temporary shelf for the ecm/tcm and mounting them and working on some wiring. Called the harness builder/tuner and he is sending me 4 more injectors. On examination I noticed I had two different types...let him know and he said he'd send out some more. I'll have to try something like that with the injectors and the rail off the intake.

I may wind up buying all new injectors at some point for piece of mind....but would like to get it running with what he provides. Kind of waiting on the new 4L85e! Guess I ought to get off my butt and pull the 200-4r

[68GMCCustom]

Got the 4 injectors in the mail this morning so did some tinkering this afternoon. Thanks for the 9v battery idea!

Short story....injectors are not firing and I am sending the ecm and tcm back to the tuner at his request.

[chevytruckluver]

Originally Posted by 68GMCCustom

Got the 4 injectors in the mail this morning so did some tinkering this afternoon. Thanks for the 9v battery idea!

Short story....injectors are not firing and I am sending the ecm and tcm back to the tuner at his request.

I know its frustrating but at least you have a direction to go and you have a vendor willing to help get the problem corrected.
keep us up to date

[68GMCCustom]

well I sent off my ecm & tcm...got them back today...installed them and tried to fire it up and my injectors still aren't firing. Tuner wants me to send it back with the harness....oh well, waiting (trans ready, they're waiting on 1350 yoke to ship) on my new 4L85e from Pace Performance anyway.

[mcbassin]

Originally Posted by 68GMCCustom

well I sent off my ecm & tcm...got them back today...installed them and tried to fire it up and my injectors still aren't firing. Tuner wants me to send it back with the harness....oh well, waiting (trans ready, they're waiting on 1350 yoke to ship) on my new 4L85e from Pace Performance anyway.

Too bad about the issues with the injectors. It really sucks you have to pull the harness and send it back. Sounds like good news on the tranny though

[68GMCCustom]

yeah I'm about ready to go back carb'd.........but I sold my intake and ignition box!

[85burb]

Maybe your motor is rebelling against the efi.
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[68GMCCustom]

...but for swapping over I got it a new trans and everything!

here's what I'm waiting for: 4L85e