Dillon93dillon

the exhaust has got done now, it starts, runs and drives.

i have a question about power tho...

it seems at about 4k i may be lacking fuel. doesnt seem to climb very fast at that point. maybe my fuel pump gauge wire is to small?

still seems kinda "doggy" although it is pushing 38.5/ super swampers. 4:11 rear gears on a th350. stock stall. (1200-1500) not sure. and a rear locker

maybe my stall is to low? but from a dead stop to the floor its got no *****, wont chirp or break the tires loose. really cant even get them to around a corner from a stop.

going to start with running the thicker wire. but im wondering if it running out of fuel or near at about 4k.

does the power im seeing from this sound about right? or am i lacking some ponys

any input here will be appreciated

rennat_2006

iTrader: (10)

Make a post in the PCM diagnostics & tuning forum or similar. Probably gonna get more technical motor help there since this is just the conversion forum

69SYC

Well alot of variables here... One IMHO i think the steel hardlines are pretty restrictive before the pump so you might check fuel pressure at the rails at WOT and see what you get... Two would the ol 350 spin the tires on it? And three these trucks were in the hard "crunch" time of the fuel crisis the TH350 has a pretty tall first gear and with no OD they ran a pretty steep rear gear ratio to keep fuel mileage "decent" have you swapped ratios in it? I had a 76 1500 with 37s and a pretty hot SB400 that didnt like to spin em without some help.. My 02 GMC with the LM7 5.3 which is what you have will spin the 35's I have on it but its no ground pounder... Its torquey from 2k to about 4500rpm they dont have a lot of top end.. 295hp is what they are rated at.. Low end "grunt" wont be as much as the SB its givin up some size and that was one beauty about a carburated small block in most rigs they would light em up with an auto pretty easy even without getting into the secondaries... And finally i love them trucks but they are TANKS lol pull a door or fender off and carry it youll see what i mean they are a HEVVY CHEVVY lol.. But with a little work that 5.3 can be a pretty hot little gem... Cam swap, a different converter, gear ratio change (perfect time for a locker) little exhaust work maybe a throttle body upgrade.. List can go on and on.. Nice job on the swap btw it looks slick

Didnt read that well enough you have 4:11s with a locker.. Im not sure it will spin them 38s stock.. Thats alot of meat

Forgot check and see do you have any codes? Is your TPS reading full throttle? MAF etc.....

Dillon93dillon

i need to check that. my brother is going to bring his laptop back over so i can check this. and before my pump is dual tank splitter, then soft line to sending unit on the tanks.

and yeah ive tooken off all of the panels, there not light haha.
and i also figured thats alot of meat, 14.50 wide... so im not sure. but i figured i would have more power than i am getting, maybe its just me tho

the old small block was on 33's and was a 4 speed manual.

yes the 1st gear on the th350 is pretty long, i wouldnt mind going to the 4l60e but i deleted all of the tranny wiring and i dont have the money to do drivelines, and adapters. blah blah blah.


im thinking maybe my stall is a little low tho also, it will still take off from the line, and very easily power brake, but it cant get them spinning and dump the brake, it will lose the wheel speed very quick.

would going to a higher stall make it more eligible to doing a burnout from a dead stop pedal straight to the floor? gm th350 originally was 14-1600, 4l60E is 2000-2300 roughly

i think it is running a little rich still to, has a light smell of a rich carbaurated sb..

GAS GUZZLING from what ive seen so far....

checked all of the MAF, IAC..etc

At idle my truck starts at 2000 rpm, without my foot on the pedal, first 5 min or so it will slowly run down to 1500, then to about 1100 after several more min, and lastly to about 860.

tried adjusting idle screw didnt do anything.

IAC i believe was reading 0 desired % or the MAF cant remember, but anyways does anyone know what the counts are suppose to be at idle?

Think we found the problem.. intake leak

rennat_2006

iTrader: (10)

Got over there and hooked up the laptop to his truck again tonight watching the live data with it running. Found that like he mentioned at cold start idle hangs around 2000rpms the slowly inches down as motor heats up all while desired idle through the pcm was way loewer than the actaul idle and that the iac count was at 0 at 800 rpms with idle desired speed was like 650 or so and that was with the throttle stop screw backded all of the way out of the throttle body. Motor was already at 195* but I grabbed a can of carb cleaner and sprayed down the intake runners and the motor would drop down in rpm's for a split second when I sprayed cylinder 3 and cylinder 4. Iremembered this problem from when I used to work at the local chevy dealership here and know that they would leak real bad on cold start then damn near seal up when at operating temperature.

Joshua8336

Keep up the Progress!!!

Dillon93dillon

replaced the intake gaskets on it today. no pictures but oh well..

started it up, idled at about 1500 for few seconds and went to 1k, then down to 750-800 about.

will need to get my brother laoptop hooked back on it and check fuel rail pressure still and IAC count but pretty sure the intake gaskets fixed my issue.

Joshua8336

how much would you charge me to do my wiring if i were to send u my harness's?

Dillon93dillon

i still think its staying up at high idle to long, it will stay there for a few mins and slowly come down. but will idle at 700-800...

comparing to my brothers silverado, the idling is nothing alike on a cold start up or even just firing it up warm.

Joshua8336

do you have a fuel regulator on it? it could also be in your tune.

Dillon93dillon

vacumm fuel regulator. built to the fuel rail.

and its just a ecm reflash, doesnt have any special tune or efi live etc.

Joshua8336

what size tires are you running on it?

Dillon93dillon

38.5/14.50/15

what are other possibilites for this idle issue? does anyone know?

unless intake is still leaking, or cracked. ecm desired idle is 600 it says, but truck is idling around 8 to 850. and will idle for who knows how long up at 1000-2000 just wherever it pleases..

Joshua8336

i have no idea...

possibly a bad sensor?

Dillon93dillon

found out my return setup was restricted.. so had to drop my tank, and fix that issue.

walbro 255 was running 110 psi of fuel pressure. so thats what blew my regulator i believe. runs better now. but i think ive still got a rich condition on bank 2 and slightly on 1.

idling issue is still existint also, will idle at about 800, but desired idle is 600.

these pictures were before the fuel fix. will have to get more for more recent.

figured out today, had Tech 2 hooked up, and monitored everything.

after fixing my fuel return problem, and looking at all of my live data, everything was doing great. 02 sensors were responding right, MAF, IAC.

figured out my high idle issue also, from what i know about wiring, i remember that the speed sensors are a AC current signal (AC current will pick up surrounding wires voltage and will throw it off), well my vss wire was ran by cylinder 7 plug wire, and down the frame rail with my rear lights. this was telling my ecm i was moving between 7-13 mph. moved the wire away from those wires, and it went to 0mph like it should.

cured my high idle issue, and the cold start high idle.

Im still wondering if im getting all of the power it has, i am now turning 38's, but even with my buddies truck (sbc350) just mild bolt on stuff on 37's, would just walk away from me im thinking.

The 5.3l swap i assumed would be more power than this, just doesnt seem to be much power for what i anticipated. DEFINETLY not getting rid of it, but i want to figure out what i can watch on live data to see if im even getting its full potential. It does read 100% when throttle to the floor on tps.

The easiest way it feels right now, like a sbc with the timing retarded to far (doggy) or heavily loaded

also seems sometimes when i punch it full throttle it will hiccup, its so small that its hard to tell but could be part of the issue

went to drive it today, let it warm up for a few min and it started kinda chugging just at idle, like a misfire, then i got my misfire check engine blinking light.
shut it off, restarted it, ran for about a min and almost died, then started acting like a missfire again. so i called it quits, im not sure what to point to this time.

checked to be sure everything was plugged in, hopefully i dont find a melted wire or something...

spearwarrior

I'm thinking about using the stock fuse block also.

Dillon93dillon

alot of people convert to the 4 wire, just the small universal fuse block, but before i found any info on that i was already done with my harness, so i didnt want to turn around. works just fine, its just big.
Either way works. but for clean look would be the 4 wire hookup

Now i drove my truck for a couple days, it ran fine (still doggy), smelled something almost like a burning smell, as i was pulling in the driveway, just figured it was from how i was driving.

Next day it starts, runs for about two min, and starts miss firing, shut it down, tried it again, and one min later starts doing it again. (seems to be as soon as the 02 sensors would be activating i think)

im wondering if the fuel pressure is to low, its at about 45-50 psi at IDLE. Full throttle gets to about 53 to 56. before i fixed my return line issue, the pump was running 110 psi, so im hoping i didnt screw it up

also today when i moved it, i noticed that if i full throttle (this is ever since its been running basically) that its very doggy, but i quarter throttled to get moving and going, and it wants to take off and go like i expected this motor to be like.

Trying to figure out what kinda problems i could have going on here, and input is appreciatedthanks

Captd

I'm dining 5.3 swap in my k10 4x4 stick I've got everything but headers can you recomend any?

Captd

Very interested in 4x4 I'm doing a swap in my 83 k10 4x4

joakwin

[QUOTE


im wondering if the fuel pressure is to low, its at about 45-50 psi at IDLE. Full throttle gets to about 53 to 56. before i fixed my return line issue, the pump was running 110 psi, so im hoping i didnt screw it up

.

Trying to figure out what kinda problems i could have going on here, and input is appreciatedthanks[/QUOTE]

fuel pressure is to low, should be about 58psi with the engine running, that's why it has low power


try this test
hook a fuel gauge up to the rail port
key on, engine off
and see what psi the pump goes up to, should be 58psi, your pump should turn on and cycle for a sec or two
and then see how long it holds that pressure,
should be able to hold that pressure for a few mins
if it cant hold that pressure, then your regulator is bad