Please help! ‘90 k1500 tbi Chevy performance mild build crate motor

[Erik the Awful]

+1

The Vortec fuel pump is very literally a drop-in replacement with no modification required.

 

[LosDoritos]

+1

The Vortec fuel pump is very literally a drop-in replacement with no modification required.

Bc of tight money I’m keeping my stock sending unit and only replacing the pump part for the FP that’s why I was asking dumber questions to be sure I have everything I need

 

[LosDoritos]

What fuel pump do you have and, what pressure are you running? The stock TBI fuel pump won't support 330 HP. For something like that, you need a fuel pump from a 96 - 97 Vortec and probably an 18LB spring. Watching your scanner, when you tip in the throttle, what does the O2 sensor do? You may be getting "lean pops".

So we did the fuel pump first then ran the timing at 0 degrees 8, then 12. Saw no difference (obv bc we didn’t mess with the regulator bc we didn’t necessarily want to) then pulled the regulator off, the spring is really big and I’ve read can go up to 22 but that was from 20 years ago so who knows and found the adjustment screw (but Holley for some REALLY dumb reason put some sort of liquid glass in between the top of the screw and top of the regulator so we couldn’t actually adjust it with the regulator on) so we used grips to change it before we put it back on the tbi and ran it still at 12 degrees (it seems to like best) and it was TREMENDOUSLY better but not completely right yet. The thing is tho that we don’t know what fuel pressure I have, we just now it’s more then before, so I’m gonna get a guage for it and also try to get that glass stuff out of the screw head so I can freely adjust it while knowing what I’m at and go from there.

 

[PlayingWithTBI]

So we did the fuel pump first

What pump did you get?

 

[evilunclegrimace]

So we did the fuel pump first then ran the timing at 0 degrees 8, then 12. Saw no difference (obv bc we didn’t mess with the regulator bc we didn’t necessarily want to) then pulled the regulator off, the spring is really big and I’ve read can go up to 22 but that was from 20 years ago so who knows and found the adjustment screw (but Holley for some REALLY dumb reason put some sort of liquid glass in between the top of the screw and top of the regulator so we couldn’t actually adjust it with the regulator on) so we used grips to change it before we put it back on the tbi and ran it still at 12 degrees (it seems to like best) and it was TREMENDOUSLY better but not completely right yet. The thing is tho that we don’t know what fuel pressure I have, we just now it’s more then before, so I’m gonna get a guage for it and also try to get that glass stuff out of the screw head so I can freely adjust it while knowing what I’m at and go from there.

There is a fuel filter that has a test port on the side of it to make FP tests a bit easier

 

[evilunclegrimace]

Fuel Pressure Test Port Valve GM Filters On FMSI Automotive Hardware

Browse Fuel Pressure Test Port Valve GM Filters in the FMSI Automotive Hardware catalog including Item #,Replaces

catalog.fmsiinc.com

Here you go.

 

[LosDoritos]

What pump did you get?

A Delphi pump for a 96-97 vortec, gpa had best price thru the shop

 

[LosDoritos]

Fuel Pressure Test Port Valve GM Filters On FMSI Automotive Hardware

Browse Fuel Pressure Test Port Valve GM Filters in the FMSI Automotive Hardware catalog including Item #,Replaces

catalog.fmsiinc.com

Here you go.

Thx but I went and ordered a gauge and holder for behind the tbi so we can leave it on there

 

[LosDoritos]

So we did the fuel pump first then ran the timing at 0 degrees 8, then 12. Saw no difference (obv bc we didn’t mess with the regulator bc we didn’t necessarily want to) then pulled the regulator off, the spring is really big and I’ve read can go up to 22 but that was from 20 years ago so who knows and found the adjustment screw (but Holley for some REALLY dumb reason put some sort of liquid glass in between the top of the screw and top of the regulator so we couldn’t actually adjust it with the regulator on) so we used grips to change it before we put it back on the tbi and ran it still at 12 degrees (it seems to like best) and it was TREMENDOUSLY better but not completely right yet. The thing is tho that we don’t know what fuel pressure I have, we just now it’s more then before, so I’m gonna get a guage for it and also try to get that glass stuff out of the screw head so I can freely adjust it while knowing what I’m at and go from there.

So I put a gauge behind the tbi and when we changed it with grips from when we had no gauge we blindly set it to 14psi (as seen in pic)

So i cleared the screw head in the regulator and started to adjust it, going from 14-16 a 180 degree turn on the screw was ab half a psi gain, once I got to 16 it got REALLY sensitive, just a nudge sent it a whole psi or more and anything past 16 the gauge was really shakey, so we set it around 18-20 and I test drove it, it backfired way more than 14 and also had a backfire that stalled it, but I think the regulator can only do ab 14, when I got back the gauge was back towards 16 with a shakey needle, but power locking it shakes the whole truck like it’s timing, so bc of a gift card I had and a power steering line that wanted to pop on me, I ordered timing tape with the line so we can see how our timings holding up and I’ve been trying to do research on this tbi for the regulator capabilities, but it seems I may need a better spring

We also had the idea of getting it driving good enough to where I can just drive it till I get enough money for a different injection system

 

[texas tough]

have u pulled some data, OBD1 doesnt give alot, but enough to figure alot out,, it sounds like its running too lean. what are your fuel trims doing ? if I recall, on these trucks 128 IS where they tend to be. I had a 89 350 that had the wrong injectors in it and it would run lean, and pre ignite in the throttle body.. every so often the engine would go into a looping surge, where the computer was trying Sto correct the fuel mixture, but it couldnt. I know the v6 injectors flow less than the V8 At the same pressure.. Ive read that big block TBi engines actually use V6 fuel injectors but AT HIGHER PRESSURE.
Also look at your 02 sensor,, these are very important for the fuel mapping.