L31 ramjet intake lt4 hotcam t56 possible?

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Happy New Year everybody. Wanted to give an update on my build, and thank everybody for helping along the way. Hope you guys had a good holiday and wish everybody the best for 2022. Thank you Oleblu and thank you Kevin aka bad79z28 for tuning this old junker. It's running great at the moment but I want more powaaa! Don't we all??!! Rigging up a cold air intake for this bad boy and hopefully get some nice cold air in the coming days. Recently purchased another Aem 30 3xx for some wideband tuning to really dial in the afr in those higher rpms so the Ramjet intake can really shine. So I hooked it up via serial port and I went for the first log and my afr dips into the 10s when I really get on it so it needs some dialing in. So I went to open the log and get a message saying " unable to open file. File header incorrect" . I tried a search but got nothing. What's the deal, Did I hook something up incorrectly? As far as the log the afr was registering and everything seemed to be logging as it should. Here's a cold start clip. Might go LS this new year idk.


https://youtu.be/tO3rMH3d1D4

[kevin87turbot]

Shoot me an email when you get a chance. I'll be glad to get WOT dialed in for you.
As far as the File header error, just try closing out the Scanner and opening it again.

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. So setup was running great up until last week when my throwout bearing went out. My engine sat outside for few days and cold/humid nights. Only thing I took off engine was cap and plugs everything else was left on the engine So buttoned everything back up and was running good but noticed it was backfiring at upper rpms out the exhaust. Thought it was my rotor screws backing out again bit it was not. Kept driving it this way and then it just died on the freeway . Had to call a buddy to tow me. So got it home and swapped out coil and icm as I thought hey maybe humidity got to these two but still no start all I get is some sputtering. Not sure what could be keeping it from starting. I was running a richer tune for only like 30 mins. Was thinking maybe I washed down my cylinders so much that I have no compression now but I think I'm jist being paranoid. No black smoke so yeah paranoid. I heard that spark starts at the crank sensor ? But I can see my rpms jump in hp tuners so IDK. Damn.

[Oleblu]

Pull a plug check fire, Confirm fuel pressure check that no fat finger mistakes are within the tune file. Basic diagnostic skill for the win here.

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[QUOTE=Oleblu;676283]Pull a plug check fire, Confirm fuel pressure check that no fat finger mistakes are within the tune file. Basic diagnostic skill for the win here.[/QUOTE

I have fuel, I have spark, reverted back to my good tune. All it does is sputter very low like it wants to run. Had a loose ground cable but still same thing. Replaced coil and icm and same thing. One thing I didn't mention was that a few weeks ago I was making a video and revving it, then noticed some puffs of gray smoke began to come out exhaust and then looked at my temp guage and it was HOT. Turned on my fans and got it cool but ever since then only at idle i will get some very light puffs of gray smoke and also my oil was getting low so I think I got something major going on here man damnn. Vortecs are very prone to cracking under heat so I will do a compression check and go from there. I wanted to believe my pcv was sucking up oil but damn I think I damaged my engine bro fawwkkk.

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Compression is good, all cylinders read 170-180. Good news but I' m stumped as too what can be causing this no start condition. Heres a pic of what my setup looks like. Everything was running good just like you see it in the picture. Thinking now I might have a fuel line clog or fuel filter clog but upon turn key prime I have 40 psi and I can manually turn FP on and have 45 psi consistent so I doubt I have a clog. I tried another dizzy cap but same thing. Rotor doesn't look bad. I doubt my dizzy gear is chewed up as rotor turns good. I have fuel, when i pull plugs they are wet. i have spark. Icm and coil both have 12 v + and have good ground. I have my coil bolted to the ac bracket, was thinking it might not be grounded good enough but like I mentioned everything was running great with everything as it is in the pic. Coil to cap wire too long? Haven't swapped out the ckp sensor. Camshaft position sensor wouldn't keep engine from running right . I don't think so.

https://youtu.be/qWiVX37vuyQ

[Oleblu]

From my experience. The camshaft sensor will cause an intermittent loss of spark/spike in spark. Usually while running cruise speeds or under heavy acceleration.

Confirm good ground continuity, Check that your not having voltage drop at the cam sensor. or interference with signal to pcm from cam sensor from a plug wire. The engine will run with cam sensor unplugged. But only in batch fire from what literature I've come across. Anyone care to confirm or debunk this?

If it has spark and the plugs are wet, use the flood clear procedure to get it to fire. 100% thottle while cranking. Most are setup at 80% minimum. No reason an engine with wet plugs and good spark shouldn't fire up using this procedure. Once it starts to come to life release the throttle. Check your rotor phase.

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From my experience. The camshaft sensor will cause an intermittent loss of spark/spike in spark. Usually while running cruise speeds or under heavy acceleration.

Confirm good ground continuity, Check that your not having voltage drop at the cam sensor. or interference with signal to pcm from cam sensor from a plug wire. The engine will run with cam sensor unplugged. But only in batch fire from what literature I've come across. Anyone care to confirm or debunk this?

If it has spark and the plugs are wet, use the flood clear procedure to get it to fire. 100% thottle while cranking. Most are setup at 80% minimum. No reason an engine with wet plugs and good spark shouldn't fire up using this procedure. Once it starts to come to life release the throttle. Check your rotor phase.

Well I tried a new cap, new rotor, new cmp, new ckp, new wires, compression is good on all cylinders 170-180 , new coil, new icm. New spark plugs, I have fuel, I have spark and I have compression but cannot even get it to fire off all I get is sputtering as if it wants to run but does not run. Ive come to the conclusion that maybe I fried my ecu? One thing I noticed after I got it home was that my main ground cable was loose as a goose. I forsure thought that was going to be the issue but no. Could that have caused the ecu to fry itself? Repeatedly trying to ground itself. Heres a video of it trying to fire up. Just sputters, doesnt even sound like it wants to start its weird. Not sure what else could keep it from starting. I have verified spark at the end of the spark plugs. Gonna have to try another ecm I dont know what to do.

https://youtube.com/shorts/IQnrObZvmu4?feature=share

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Found out my issue. Stripped dizzy gear. It was a melonized gear. What to do after this happens? Metal in the oil pump? In the filter? Drop pan? What distributor and gear should I run with the lt4 hotcam? As far as I know the melonized one was the one to run.

[Oleblu]

melonized is correct. Your distributor gear smashed into cam gear. Shim your distributor up with atleast one more distributor gasket. Do not tighten it so tight you can't turn the distributor by hand with a bit of effort. You should really take some measurements to confirm. Pull your front cover and check your cam plate. To assure its not caused from cam walk.

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melonized is correct. Your distributor gear smashed into cam gear. Shim your distributor up with atleast one more distributor gasket. Do not tighten it so tight you can't turn the distributor by hand with a bit of effort. You should really take some measurements to confirm. Pull your front cover and check your cam plate. To assure its not caused from cam walk.

The last time I pulled the dizzy I checked the wear pattern on the gear and it looked really good. When the distributor is all the way down, you can see it has play side to side and front to back. I might have not put it back in in the same position maybe a little cocked. Is this just with the stock distributors? I remember my hei never had this play but the vortec dizzy is real skinny. Even with the thrust plate between the cam and timing gear do you think it can walk? Wouldn't there have to be a timing gear failure for the cam to walk? You think my oil pump is shot due to the metal in there.?

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Upon further inspection, shaft on dizzy is bent. Definitely not a performance distributor.

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So turns out I used a .490 melonized gear on the smaller .430 Vortec shaft. Which is what caused the gear to strip. I have no Idea how I missed that but oh well. Back up and running. I believe I need bigger injectors. I have read that 80 % injector duty cycle is the most you want at WOT but my duty cycle hits 85% at only 4k rpm. Above 4300 it maxes out 100% and the engine feels like it just cuts out, no power. Is this a sign I need bigger injectors?

[kevin87turbot]

So turns out I used a .490 melonized gear on the smaller .430 Vortec shaft. Which is what caused the gear to strip. I have no Idea how I missed that but oh well. Back up and running. I believe I need bigger injectors. I have read that 80 % injector duty cycle is the most you want at WOT but my duty cycle hits 85% at only 4k rpm. Above 4300 it maxes out 100% and the engine feels like it just cuts out, no power. Is this a sign I need bigger injectors?

Yes, anything above 100% IDC means that they are maxed out. A truck flexfuel injector will work nicely.

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Yes, anything above 100% IDC means that they are maxed out. A truck flexfuel injector will work nicely.

Just scooped up a set of 12613412 injectors. Would these be a good fit? Probably should have asked before I bought them. Looked em up and says they are rated at 42 lb at my fuel pressure, 43 psi.
I have been running 25317628's for a while now rated at 21 lb . I feel they were to small to begin with for a 350 with my mods. These new injectors are 42 lb almost double.

[Oleblu]

Good choice ev6 connector swap required. Make sure the data is correct the first time around.