My tbi conversion was a success!

[Shawn1989]

details:
gm 300hp crate engine - same as gm 330hp vortec, just with marine heads.
was carb before it went up in flames
bought tbi and harness from 97 gm 350
reworked the whole thing ditching what i don't need

and here are the results, no tune [no idea how], first crank. it seems like its starving of fuel up in higher rpm where it stutters for a millisecond..... i have external regulator set at 18psi..... would this be fuel related or tune related? i can only rev to about 4500 before it stutters again

https://www.youtube.com/watch?v=4ZvIvqdXKoI

[Six_Shooter]

Did you have you the Gas Monkey extinguisher handy? You know, just in case.

What are you using for an ECM? We can advise better with knowing all of the details of your swap. It might be too much fuel with 18 PSIG of fuel pressure. Are you using vacuum reference with the regulator?

[Shawn1989]

Did you have you the Gas Monkey extinguisher handy? You know, just in case.

What are you using for an ECM? We can advise better with knowing all of the details of your swap. It might be too much fuel with 18 PSIG of fuel pressure. Are you using vacuum reference with the regulator?

lol, yeah its mounted inside of the car

16196395 is the ecm code no vacuum reference

[Shawn1989]

definately a fuel cut. only had 1/4 throttle and it still chopped fuel at 4500 or so. whats the lowest the regulator should read? ill try bumping up fuel pressure on regulator to see if that helps or if it is pcm related

[Fast355]

definately a fuel cut. only had 1/4 throttle and it still chopped fuel at 4500 or so. whats the lowest the regulator should read? ill try bumping up fuel pressure on regulator to see if that helps or if it is pcm related

I think fuel kill is set at 4,800 rpm and 98 mph on most stock TBI 350 calibrations.

[Shawn1989]

also buddy had mentioned park/neutral limiter. possible?

[Shawn1989]

I think fuel kill is set at 4,800 rpm and 98 mph on most stock TBI 350 calibrations.

that explains it. thanks :D

[Six_Shooter]

If anything I would lower the fuel pressure. 18 with no vac ref is too high IMO, for a stock TBI set-up on an otherwise stock engine.

There is also a thing that happens when you feed too much fuel into an engine, it stumbles, and you could be experiencing this.

Depending on the actual calibration (bin) you are using and the ECM, you could be hitting a max rev limiter or a P/N limiter. From your description you're using a '97 PCM, I would assume to match the harness? I'm not real familar with the OBD2 stuff, but I know many do have a P/N limiter.

[Shawn1989]

If anything I would lower the fuel pressure. 18 with no vac ref is too high IMO, for a stock TBI set-up on an otherwise stock engine.

There is also a thing that happens when you feed too much fuel into an engine, it stumbles, and you could be experiencing this.

Depending on the actual calibration (bin) you are using and the ECM, you could be hitting a max rev limiter or a P/N limiter. From your description you're using a '97 PCM, I would assume to match the harness? I'm not real familar with the OBD2 stuff, but I know many do have a P/N limiter.

ooops, no i meant its from a 93 ;) haha! sorry its obd1. i was trippin for a second

ye harness matched

[Six_Shooter]

Ok, '93 I can help with.

What is the BCC and ECM service number? Looking up the limiter will not be hard. In the 4000s sounds kinda low, though I have seen it.

It won't have a P/N limiter AFAIK.

[Fast355]

Ok, '93 I can help with.

What is the BCC and ECM service number? Looking up the limiter will not be hard. In the 4000s sounds kinda low, though I have seen it.

It won't have a P/N limiter AFAIK.

Limit in P/N and Drive should be the same RPM and IIRC its 4,800 rpm.

[Shawn1989]

i listed the ecm number above and ye mine cuts out at 44-45. ha! gayyeeeee!
time for a tune to bump it up to like 65 and get this motor running right.

but, i wanna do vortec heads and 454 throttle body before the tune so ill just deal with it til then.

[Six_Shooter]

Ok, so what's the BCC (4 letter code on the MEMCAL)?

[Shawn1989]

Ok, so what's the BCC (4 letter code on the MEMCAL)?

dunno, i'll let you know when i get off work tonigh at 11

[Shawn1989]

I'm guessing bjlh