GM says anywhere from 9 to 13 PSI for TBI. But that is a lie! It may run under 13 but I have yet to see one run well under 13.
CK5
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Searching for torque
- Thread starter ccarley
- Start date
mine was stock with 9......
I'm not a gambler but I would bet you it ran better at 13 because it's a sure thing...
Could be some gauge error too but that's way off.
Could be some gauge error too but that's way off.
I was a little surprised it was that low too, i figured it was gonna be 11ish... the more i gave it, the better it ran.. finally ended up at about 13.5 to 14....
Some people just don't beleive me but it's been proven over and over again. Oh! You just verified it as well! 
glad i added one of these to my project STUBBY truck then. . . 
http://www.autometer.com/cat_gaugedetail.aspx?gid=3303&sid=7
http://www.autometer.com/cat_gaugedetail.aspx?gid=3303&sid=7
Fuel pressure gauge is a great tool for EFI. But if it's under the hood you can't see any fuel drop pressure issues when driving. I have a long rubber hose on a gauge hooked to a tee for TBI so I can bolt it on someones vehicle and run it up through cowl under a windsheild wiper. Now I can see if there is a drop in pressure at WOT or at high RPM. Been very handy!
Also notice how the bottom of your air cleaner is shaped. On the first Gens there is a factory spacer. Loose it.
I fabricated a steel funnel to the bottom of my 14" air cleaner to unshroud the injectors with wonderful results, working much like a velocity stack.
Between that and the fuel pressure up-treatment the power increase from 1000-2500 is noticable without doubt.
I fabricated a steel funnel to the bottom of my 14" air cleaner to unshroud the injectors with wonderful results, working much like a velocity stack.
Between that and the fuel pressure up-treatment the power increase from 1000-2500 is noticable without doubt.
Never thought of that... great tip!
ccarley
1/2 ton status
I've been running now for a few weeks with the throttle body spacer, and the salad bowl, keeping the air filter lid open.
The difference in power between the lid open & closed is enough to feel for sure; and without my cold air snorkel, it's running better with the lid open. The lid at this point does just kiss the insulation on the bottom of my hood.
I haven't actually done the math yet, but I'm not seeing any gains in fuel economy. That's fine; I haven't seen any decrease either. The power increase is nice.
The salad bowl mod is interesting; the engine sounds different just off idle now. Has more of that Tim Allen grunt sound out of the flowmaster now. *Flowmaster installed by previous owner. Not my first choice living in Sonoma County, CA, where Flowmaster's HQ is 5min from my office in Santa Rosa. Everyone has a flowmaster here!
I had to change my oil last week and install new brake pads up front. Otherwise, I haven't had time to install the pod spacer or order the adjustable fuel pressure regulator. Still on my list for sure!
Clay
The difference in power between the lid open & closed is enough to feel for sure; and without my cold air snorkel, it's running better with the lid open. The lid at this point does just kiss the insulation on the bottom of my hood.
I haven't actually done the math yet, but I'm not seeing any gains in fuel economy. That's fine; I haven't seen any decrease either. The power increase is nice.
The salad bowl mod is interesting; the engine sounds different just off idle now. Has more of that Tim Allen grunt sound out of the flowmaster now. *Flowmaster installed by previous owner. Not my first choice living in Sonoma County, CA, where Flowmaster's HQ is 5min from my office in Santa Rosa. Everyone has a flowmaster here!
I had to change my oil last week and install new brake pads up front. Otherwise, I haven't had time to install the pod spacer or order the adjustable fuel pressure regulator. Still on my list for sure!
Clay
Cold air increases power. Turning your lid upside down lets in hot air reducing power. But turning the lid over makes it sound like more power.
There are little gadgets all over eBay that wire into the Incoming Air Temp sensor to adjust the reading to think it has colder air which adds more fuel and more power.
I guerentee if you check milage with cold air intake intact and cold air intake removed you will get better fuel milage with cold air inlet intact. Just look at any car from the last 15 years and you will see cold air intake. The aftermarket is loaded with cold air intakes.
There are little gadgets all over eBay that wire into the Incoming Air Temp sensor to adjust the reading to think it has colder air which adds more fuel and more power.
I guerentee if you check milage with cold air intake intact and cold air intake removed you will get better fuel milage with cold air inlet intact. Just look at any car from the last 15 years and you will see cold air intake. The aftermarket is loaded with cold air intakes.
ccarley
1/2 ton status
eagle mark: I totally agree. Unfortunately, the previous owner removed the snorkel, and I haven't found all the parts yet at the junkyard to hook it all back up.
As it is, no matter what I'm sucking hot air, lid open or closed. Having the lid open made a positive difference in fuel mileage (documented
) and helped with uphill power.
When I do find the snorkel parts, I'll be hooking them up for sure.
I do always laugh at the "cold air intake" ads & descriptions. Doesn't the stock airbox on new vehicles suck air from outside the engine compartment already? LOL
As it is, no matter what I'm sucking hot air, lid open or closed. Having the lid open made a positive difference in fuel mileage (documented
) and helped with uphill power. When I do find the snorkel parts, I'll be hooking them up for sure.
I do always laugh at the "cold air intake" ads & descriptions. Doesn't the stock airbox on new vehicles suck air from outside the engine compartment already? LOL
Yup! But for $300 they do it better...
Yup! But for $300 they do it better...
No, $300 gets you some fancy looking parts and usually a K&N air filter.
Wouldnt the stock air cleaner setup that all of our trucks had technicaly cold air intakes??
TBI's, yes... hose to rad support.... older carb'd, etc, no...
On the TBI trucks yes! Very good setup with the hot air tube to an exhaust manifold with automatic valve to shut when motor is warmed up. Excellent setup!
I have used this same setup on many older Scouts, Jeeps and such after doing a TBI conversion. Makes them run just as good as our trucks at any tempreture! Good Stuff!
Only improvement you could make to the stock setup is a K&N air filter.
ccarley
1/2 ton status
Update!
I believe the Accel HEI module died yesterday. I (ironically) was at Autozone to get a master cylinder for my VW Bug, and when I parked, the idle was surging badly and my service engine soon light came on. Checked the code on the spot and came up with 42 of course.
Now, on re-fire, there was no light, and it drove home OK. Once home, I checked the codes, and 42 was still there. I swapped the module with my new spare Jeg's unit (might not be the best, but it was new), fired up, and ran fine but after driving around the block, with no light, 42 is still in the computer. Wonder if it's stored for a bit as driving to work this morning too it was running "nice" it seems. I did clean the base of the dizzy, and used the grease that the module came with.
I still have not found the snorkel from the air cleaner to the radiator support, but I haven't had a lot of time to look either. Work has been a bit much.
On another update... before I did my smog test a while ago, I ordered the Accel truck tune-up kit deal that had the cap, rotor, plugs, and wires. The rotor looked to have a wider blade on it than my old one, so I thought it would be good. The wires are nice, and the plugs, although advertised as U-groove, are plain copper plugs. The cap & rotor actually suck, as one or the other are molded off-center... so after a bit of time, they self clearanced... I did save the old cap & rotor and am not sure if I want to reinstall those or get a new replacement set.
And again, I have not yet installed the pod spacer or picked up the adjustable fuel pressure regulator. However, it's been running like a champ otherwise, and even loaded with 1/2 ton of firewood, climbing hills with no problem. Yes, even with the 3.73's and 35's (not using OD of course).
Clay
I believe the Accel HEI module died yesterday. I (ironically) was at Autozone to get a master cylinder for my VW Bug, and when I parked, the idle was surging badly and my service engine soon light came on. Checked the code on the spot and came up with 42 of course.
Now, on re-fire, there was no light, and it drove home OK. Once home, I checked the codes, and 42 was still there. I swapped the module with my new spare Jeg's unit (might not be the best, but it was new), fired up, and ran fine but after driving around the block, with no light, 42 is still in the computer. Wonder if it's stored for a bit as driving to work this morning too it was running "nice" it seems. I did clean the base of the dizzy, and used the grease that the module came with.
I still have not found the snorkel from the air cleaner to the radiator support, but I haven't had a lot of time to look either. Work has been a bit much.
On another update... before I did my smog test a while ago, I ordered the Accel truck tune-up kit deal that had the cap, rotor, plugs, and wires. The rotor looked to have a wider blade on it than my old one, so I thought it would be good. The wires are nice, and the plugs, although advertised as U-groove, are plain copper plugs. The cap & rotor actually suck, as one or the other are molded off-center... so after a bit of time, they self clearanced... I did save the old cap & rotor and am not sure if I want to reinstall those or get a new replacement set.
And again, I have not yet installed the pod spacer or picked up the adjustable fuel pressure regulator. However, it's been running like a champ otherwise, and even loaded with 1/2 ton of firewood, climbing hills with no problem. Yes, even with the 3.73's and 35's (not using OD of course).
Clay
When I had my stock 350 I replaced the cat with a high flow version $40 and the y-pipe I think $40 also. That made the biggest improvement for me. The hunt for power on the stock motor IMO is a futile effort. I was never able to get enough until going to a 383. At which point he might be better of with a 5.3L or 6.0L since he's in california and has to pass tough smog requirements.
depends on his goals I guess.
Dont know what the grease does but I didnt put it under my accel unit and mine has run perfect and faithfully for over 1 1/2 years now. Should i take it out and add the grease
