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Hot 355 runs awesome but won't idle..?

in my last post i said im gonna just pull it off which i am in the middle of right now... waiting for my brother to get here so he can hold it up while i put the rtv on. The psi is ok (which i found out yesterday) its the chip that is the problem. The holley tbi has a built in adjustable pressure regulator and that is not the problem. If you read a little ways back you'll see that other ck5ers had this same problem with a stock motor after they bolted one of these tbis on. the injectors are over 4x's the size of the stock injectors and i have more psi goin to them. I haven't taken a psi reading yet but i estimated 35 because its a 13-22 adjustable regulator with a 45 psi pump. the efi shops tell me that that much psi will end up being higher than the regulators rating.

I think this will end my problems and all my i got problems posts but i won't know for sure until i get the chip. I can't just go out and buy one with this many mods. Seen people do that with hot motors and it ends up running worse with the commercial(not custom) chip than it did with the stock prom.
 
Nothin but problems over hear......

Ok I just snapped a bolt off in my head. somebody tell me who put a damn curse on my new motor! I guess my bro grabbed an aluminum bolt when i said grab a manifold bolt out of the bolt box and she sheared off right when the torque wrench clicked... now im waitin on a reverse drill bit." sigh".:frown1:
 
Just be patient with it brother. Take your time and dont get frustrated when working on it or you'll f' it up. A broken off bolt isnt a big deal as long as you take your time taking it out. I snapped a bolt off on my timing chain cover when I put my new engine back in my truck, and couldnt for the life of me find another bolt. I just bolted in all of the other bolts and rtv'ed the one that broke off, and it works fine.

As for the rest of your problems, yes a new chip should solve 99% of your driveability problems. If I were you, I would go to www.cfm-tech.com and order a fuel psi adapter with guage. For like $60 you can get an adapter for your inlet fuel line into the tbi with a guage fitting on it. It also comes with a nice vdo guage. I think the guage they give you only goes to 15 psi, but im sure they can get a higher one if you call them. Thats what I have and it sure is nice to have an underhood fuel pressure guage. They also custom burn chips if you give them your specifications. www.turbocity.com will also burn you a chip, but I have never dealt with them before.

BTW- cfm-tech also has a couple of nice power adding spacers and gizmos. I dont know if it will work an a non stock tbi, but I put their "power package" on my truck last weekend and it is like a whole new truck. Throttle response is amazing, and the power gain was more than I ever thought a tbi spacer, injector spacer, and adjustable pressure regulator could ever do. Trucks magazine did a write up on their power package and stated "the old tbi 350 now even begs to be flogged around town." I thought "yeah right, a tbi engine that begs to be flogged after a few simple mods." Well, damn, my truck begs now too.
-Harrison
 
Turn down the fuel pressure. I'm running a 383 at 18 PSI with no driveability issues. Lots of other mods too though. But 35 PSI on a TBI is too much.
 
How much are the inj/tbi spacers. the holley tbi has an adjustable regulator but i may need 2 to get the psi down... still don't know for sure. I might be able to just leave the psi where it is because i don't have any way to read it and all you tell me 35 is too much but it runs like a f******* ethiopian when you bring up the rpms so either 35 is ok or the psi is lower than i thought. Either way it is setup to get as much rpms out of a 2bbl tbi as you possibly can. My motor wants to make all its peak hp at about 4000-5500. I am hoping to get at least 5000 with this setup because tbi is a lot cheaper than goin tpi or mpfi and a 375-400 hp tbi 350 is a rare piece. the motor will make about 411 at 6 grand but i don't see a tbi handling that kind of rpms.

What do you mean when you say too much?

I know the psi but what is the problem with that much?

Not blowin the injectors out and i think once i get a chip to lean out the bottom end i should be good to go.
 
Xtreme Off-Road said:
Turn down the fuel pressure. I'm running a 383 at 18 PSI with no driveability issues. Lots of other mods too though. But 35 PSI on a TBI is too much.
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Sounds like an echo in here dirtwarrior17?...:surepal:

I tried learnin him in the post at a much earlier date. Nothing against you at all. I'm just glad to see someone else shares my opinion:thumb:

John
 
If you increase the fuel pressure at the injector, without changing how long the injector stays open, more fuel will come out with the same amount of injector "open" time. Make sense?
 
From what I've seen, xtronics pocket programmer 2 is the programmer to get, while everything else needed comes from moates.net.
 
I was just sayin the top end works real good but the bottom is my main priority. It's real bad for a brand new motor to idle that rich. I was thinking of buying a cheap stock computer off ebay for about 20 bucks then have it reflashed. I can't drive it to get it burned the right way so I got to send for a chip or get a computer reflashed.

The theory on the high psi is the reason i put a 45 psi pump in there... everyone was telling me a 2bbl won't get over 5 grand so i stuffed a high psi pump in and still haven't found out if its gonna work yet.

I was just talking to my dad about the whole more fuel per pulse thing....

Yo i know its illegal but if any of you are thinking about spending 50 bucks on a desktop dyno type software, you might want to go to kazaa.com dl the free version of kazaa and then search for desktop dyno. You can dl the whole dyno program for free and music, movies, games, 4x4 videos etc. all for free

(you didn't hear it from me but....... theres some other good videos on there if ya know what i mean):saweet: :pimp: :cool1: .

hehe....
 
I can't find it now, but I was just looking at a programmer that cost $47. Some kind of "DIY" programmer, but it comes fully assembled as I understood it.

There was mention of it recently on thirdgen.org in the diy prom or dfi ecm forum. Lot cheaper than the PP2
 
Can somebody tell me what i need to burn my own chips...... i don't own a labtop. I might be able to rig a 100 ft cord off my PC and drop it out my window right to the blaze.


I Really need this info because i've never heard of these programmers for an 88.

What is the full price of what i will need and where can i get it/them?
 
dirtwarrior17 said:
The theory on the high psi is the reason i put a 45 psi pump in there... everyone was telling me a 2bbl won't get over 5 grand so i stuffed a high psi pump in and still haven't found out if its gonna work yet.
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You can dump as much fuel as you want into the engine but it won't help it unless it can get more air. you need to either install a Holley or Turbo City TBI with 2" bore, or bore out your own. I bored out mine to 2" and use throttle plate off of a Rochester secondaries.
With 18 PSI and 2" bore my 383 produces gobs of power, but I stop the spin at 4500 RPM.
 
dirtwarrior17 said:
you tell me 35 is too much but it runs like a f******* ethiopian when you bring up the rpms so either 35 is ok or the psi is lower than i thought. What do you mean when you say too much?

I know the psi but what is the problem with that much?
Click to expand...
Yes, 35 is too much. No, 35 is not ok. I believe you answered you own question when you said "or the psi is lower than I thought." Where exaclty did you get the "35psi" reading if you havent checked it and dont have a guage? When we say too much psi, we mean you will have some serious driveability problems. The engine will run far too rich, and with 35 psi, I am 99% sure your truck wont even start. Fuel psi is not like tire psi. A .25 or .5 of a psi increase makes a drastic difference. For example: I put some cfm-tech performance goodies on my truck this past weekend. From the factory, my truck was adjusted at 13 psi. I turned it up to 13.5 when I put the parts on. It ran good when cold, and great when warm. I turned it up to 14 psi the other day and ran into a problem. This psi increase led to a highly noticeable increase in power when the engine warmed up, but when it was cold it suffers from too much fuel, and not enough air. So therefore it idles crappy, very rough. When it warms up though, it runs like a champ. So I can live with stumbling/rough idle for the 5 minutes it takes for the engine to warm up, just to have the power gained from the psi increase. If I were to increase the psi to 14.25, I would probably squeeze out some more power, but the truck would also probably cut off and require multiple restarts when it was cold.

My suggestion to you is:
A) Get a pressure guage so you dont have to guess the fuel pressure, and we can give you more accurate information.
B) Why dont you try turning the fuel pressure down a little bit to see if that helps it out anymore.
C) Get a custom chip burned for it.

Thats all.
-Harrison
 
No did not see that.

Could it be that you have your pressure so hi that the injector can't open every time at idle because the pulse width is so small. Use your timing light and look at the spray pattern, it may reveal something.
 
lol i know it is not tire psi and if you read my other posts you will see that I know more about this than you think. This is NOT a stock motor by any means and is gonna want a lot more fuel than a stock 350. The cam has a real loping idle and if it runs rich at idle it wants to die becuase the computer can't take that much change in the cam without a chip. This thing sounds real good when i give it 1/4 throttle and let it warm up then it will idle ok for about a min then get rougher and shut off. It runs very strong in the middle and couldn't sound healthier but its the idle im having problems with.

My dad used to rent a shop next to a chevy dealer master mechanic and i had him come out and take a look at it a while ago and he said the psi is ok. I really think a custom chip will solve ALL my problems but im still waitin ont eh $$.

Like i said in an earlier post the psi was a guess. What would you think it would be with a 45 psi pump and a 22 psi regulator? I really need to get an idea where this is at.

That sounds like a good idea with the timing light thanks.
 
dirtwarrior17 said:
Can somebody tell me what i need to burn my own chips...... i don't own a labtop. I might be able to rig a 100 ft cord off my PC and drop it out my window right to the blaze.
Click to expand...

I believe that info is in post #28 or 29.

Start reading the DIY PROM article by Traxxion over on thirdgen.org, it gets no simpler than that, and will require learning.

You wouldn't be the first one to run a PC in the truck in the driveway, but it is necessary to be able to drive and log. Driving under load is an entirely different situation than sitting at idle and revving the engine.
 
I guess im at the mercy of my local efi shop then. Can't get my hands on a labtop. 450 bucks for a dyno run and a custom chip.... it'll be worth it for 375 hp
 
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