Need Startup Help
The engine will not start. Need suggestions. This is a new engine. Ls1 stroked to 383. Using the Ultimate Fitech system 74002 complete with HyperFuel in tank fuel pump. When you crank the engine, it sounds like it wants to start, spits and sputters and backfires.
- First thing was to install a new tune in the handheld programmer, did that and no change.
- Then thought was not enough fuel. Sprayed ether in and got big backfire out of the front of the intake. But cranking did not change. Installed a fuel pressure gauge at the fuel rail. Got 58 lbs. steady.
- Thought is might be a bad ECU from Fitech, They swapped the ECU but no change.
- Thought it might be some bad coil wires in the wiring hardness. Ohm'ed out all eight coil firing wires from the ECU to the coil packs. All tested good.
- Ok, list is getting shorter. Maybe I screwed up when I built the engine and installed the timing chain and gear off one tooth. Took front of engine off and checked, was hoping to find it off one tooth, but is was not. the timing marks line up perfectly.
- During cranking, the rpm is 150 to 450. Varies because it will hit and die and hit and die.
Now I have run out of options. Looking for any suggestions.
List of questions I have
- How many vacuum holes are there in the Ultimate Fitech intake? I have the 4 in the back under the plenum plugged. I don't think there are any more, but wanted to ask. Maybe a vacuum leak?
- How much initial timing should be used? The handheld shows 4 to 4.5 degrees during cranking. Don't know what it should be since I have not used this system before.. Was wondering if there is a way to add timing like when you used to have to turn the distributor on an old school engine to get it cranked. Checking the Pro tune section of the handheld, it shows the initial timing to be 18 degrees. Not sure why the handheld shows 4 during cranking. I have tuned other ls engines using HPTuners and they all show about 18 degrees during startup.
I welcome all suggestions on where to go from here. If anyone would like to discuss on the phone, I will be glad to provide my cell number.
Thanks
Baffled
I have seen guy's get the coil harness backwards. You know what that could cause.
I agree, confirm you have the correct coil harnesses going to the correct sides.
Confirm the "D" & "P" tags are correct on the HARNESS plugs (not the plugs in your coil harnesses). The "P" side, 2, 4, 6, & 8 should have two orange wires in it. The "D" side, 1, 3, 5 & 7 should have one yellow wire in it.
Yes, verified that. As I said, I ohm'ed out each individual coil wire from the ECU connector all the way to each coil. If they had been backwards, the ohm testing would have revealed that.
OK, that's good.
This may seem silly but have you checked the fuses? I mean, pull them out and test with a meter or self powered probe/light.
It's been known to show power on both test points of a fuse when plugged in even if it's blown.
I checked, yes. But i would think if it was a blown fuse, I would not get any spark. It spits and sputters and backfires.
I'm in the same boat with the 70050 kit. Spits and sputters, that's it. On mine for some reason the fault codes for the injector do not match the cylinder. I'll pull # 4 it shows fault code for #7. Hopefully fitech will be open tomorrow. I guess someone named Cody is the guy you want to talk to over there.
If I had any fault codes, that might help in the trouble shooting. But mine is clean, no codes.
Just finished putting it all back together after checking the timing chains marks. Tired to crank it again and got the same results, spits and sputters. While I was putting it back together, I gapped the plugs to .055 instead of the .040 they came with. But still no change.
I checked the Timing Advance with the handheld during cracking, and see it changing anywhere from 4 to 18 degrees. I bumped the spark timing at idle from 18 to 22. No change. Took it to 25, no change. Took it to 15 and it did not spit and sputter as much, took it to 10 and it would not spit and sputter at all, but would not hit at all. Put it back to 18 and now we are back to where we started. While cranking, pressed the trottle about 50% and backfire and flames come out the intake.
Still do not have any error codes.
Any suggestions?
Backfiring and flames coming out the intake when trying to start is usually a sign that the ignition firing order is wrong. It's ignition spark while an intake valve is open due to incorrect ignition sequence (spark at the wrong cylinders) or the ignition timing being so far off it's ahead or behind by one ignition cycle.
But you've said that you confirmed the ignition firing order.
What is the engine block you're using? Do you have the correct crank sensor? 24x black sensor, 58x gray sensor. Is the ECM programmed to match?
There's no way that I know of to "watch" the cam sensor as we can the crank sensor via the engine speed. Have you swapped the cam sensor with another one to confirm the one you have is good?
Although I doubt this is the problem, have you confirmed proper fuel pressure during cranking?
You mentioned that Fitech swapped your ECM. As that wasn't the fix, they should continue with you until your problem is identified and a solution is determined.
Having still failed, you'll need to get with Fitech. See if you guys can get through to Dominic.