I have an old style GM perf block (010) and a set of vortec heads on it. I bought the gm perf manifold to keep my TBI. It doesnt seem to run right. I'm not sure if its the ODB1, or what. I'm about to carb it if I cant get a solution.

Codes?

I wouldn't waste my time with TBI.

Throw a manifold and carb on it and drop a HEI distr in and call it good.
Oh, and remove the TBI wiring harness and buy a fuel pressure regulator or drop the tank and replace it with carb tank.
Then mount a low pressure elec pump somewhere or get the fuel pump and push rod for a mechanical pump.

That way you will be sure it was definately the TBI that was causing the problem.

I wouldn't waste my time with TBI.

Throw a manifold and carb on it and drop a HEI distr in and call it good.
Oh, and remove the TBI wiring harness and buy a fuel pressure regulator or drop the tank and replace it with carb tank.
Then mount a low pressure elec pump somewhere or get the fuel pump and push rod for a mechanical pump.

That way you will be sure it was definately the TBI that was causing the problem.


I am surprised to read that from you..LOL....OK OK maybe it was sarcasm?

I wouldn't waste my time with TBI.

Throw a manifold and carb on it and drop a HEI distr in and call it good.
Oh, and remove the TBI wiring harness and buy a fuel pressure regulator or drop the tank and replace it with carb tank.
Then mount a low pressure elec pump somewhere or get the fuel pump and push rod for a mechanical pump.

That way you will be sure it was definately the TBI that was causing the problem.

I am surprised to read that from you..LOL....OK OK maybe it was sarcasm?

I believe it's realism with a hint of sarcasm. Since the guy obviously doesn't know his ass from a hole in the ground when it comes to GM TBI systems and hasn't done anything to try and educate himself on the subject, trying to talk him through any kind of diagnostics would be a total nightmare and an excercise in futility. He probably is better off with a carb.

Clearly your not using a chip from a tbi truck that came factory with a .010 over block, vortec heads, and aftermarket intake and exhaust....

tbichips.com

True, not known are HOW it..... "it doesn't seem to run right".......
The block should not make any difference nor the heads to any huge extent (at this moment not considering EGR or no EGR as we don't know WHY "it doesn't seem to run right")....but the cam from the old performance block will. We ALSO don't know if the TBI was off a 305 or 350 and going onto a 265, 283, 305, 350, or 400 SBC....we just know it is a SBC because he is using Vortec heads and a GMP Vortec/TBI intake (assumption... :) ). We don't know any codes, drivabiltiy issues....hell, we know nothing other than "it doesn't seem to run right" <<<< Not much to go on, crystal ball is out of order at this time (I dropped it) and my psychic is on vaca...................

True, not known are HOW it..... "it doesn't seem to run right".......
The block should not make any difference nor the heads to any huge extent (at this moment not considering EGR or no EGR as we don't know WHY "it doesn't seem to run right")....but the cam from the old performance block will. We ALSO don't know if the TBI was off a 305 or 350 and going onto a 265, 283, 305, 350, or 400 SBC....we just know it is a SBC because he is using Vortec heads and a GMP Vortec/TBI intake (assumption... :) ). We don't know any codes, drivabiltiy issues....hell, we know nothing other than "it doesn't seem to run right" <<<< Not much to go on, crystal ball is out of order at this time (I dropped it) and my psychic is on vaca...................

o.O heads have a huge part in throwing off the computer...

Who knows what the problem is here but vortec heads and TBI together aren't a good combo in my opinion. The heads don't heat the manifold well. Can be tuned out to a point but on a stock system may have issues.
"Don't run right" is all we know about it so who the hell knows.:shaking:

o.O heads have a huge part in throwing off the computer...

I would agree...but not a huge part. We do or don't know if he has EGR connect....that would cause an isue with drivability. Many TBI 5.7L have had Vortecs installed with the GM TBI/Vortec intake....they do lack EGR/heat crossover and that does cause some issues. A friend of mine had done this very swap....when the GM intake 1st came out....ran OK.....Had some part throttle issues but they weren't huge by any means. EGR can be tuned out of the chip.....if he even has the correct chip.....again 305/350..? (original poster).

The verdict here is.......we don't know......because we don't know what the hell his issues are so we can't......let me rephrase.....won't help due to the lack of information.

EDIT: Let me add....personally for a low rpm truck engine....the TBI/swirlports heads can be perfectly acceptable. For a TQ'y engine application below 4000rpm they actually flow (pretty) well at low valve lifts and have good port velocity. I think the Vortecs would obviously get the nod in the HP oriented applications.

I have been driving this combo for 5yrs. It has always had its quirks. It has a crane 4x4 hyd cam. It is an EGR set up. The codes are all soft codes, (it will not set a hard code). The EGR is coming from the drivers exh. maniford from a GM part EGR pipe that comes over the manifold. It has alot of pep, but likes to surge in mid range. The truck has a 700r4 tranny(the third since this engine swap), the engine just eats them alive. The final gear ratio is 4.11:1. It sets on 33x10.5x16 tires. The exhaust is 3" to a single in dual out flowmaster 2.25, forty series. The valve train is crane 1.6:1 Roller rockers, with dual valve springs. The pistons are true flat top fel-pro's, with regular head gaskets. Compression ratio after cc'ing the heads is 9.5:1. It has the original prom chip in the ECM for the 350 that came in the truck. No computer mods have been done. All sensors are intact. It has the factory ignition.

I built this engine from the plans in perf chevy that they put the same engine in a 90 camaro and it dyno'd at 320hp/350ftlb.
The engine is over bored to .040. It has a high volume oil pump(60-80psi).

I think that I listed ALL the info now. It has the correct spark plugs for the Vortec Heads, and new fuel injectors(factory spec for 350 engine)

Oh yeah, it runs rich as hell!!!!!!!!

Sometimes too much air does that. Stuff a sock in it.


TROLL!!!

And you are running a stock chip? I hate to assume things becasue we all know what happens when things are assumed...


But I'm with Bill on this. You don't seem to have a clue as to what you are doing when it comes to TBI, and I'd bet that even if you were given good advice that you wouln't follow it, do something else, and still whine about how fuel injection is crap.

I posted all the specs of my truck. I am still not getting anything other than sarcasm, or unhelpful tips/tricks. I appreciate the guys/gals who have actually given me helpful info, but the stupid remarks are not appreciated. I have run the codes several times, but no codes are set. The engine runs great off the line, full throttle, but at half throttle it surges. I am not unsatisfied with the setup, but looking for a fix. If I have to carb it, Oh well. I have tried a Holley TBI on this combo with the same results. I was hoping that this was a common problem, and that I could "tune" it out. This engine combo has<30K on it and I have hauled a trailer coast to coast. I am currently in the millitary, and I havent had the time to play with it to narrow the cause down. I drive it for a few months at a time and then it gets parked for the rest of the year. IF I COULD PLEASE GET SOMEONE TO GIVE ME HELPFUL INFO, I WILL CONTINUE WITH THIS SITE IF NOT, ENJOY THE FREEDOM I DEFEND FOR YOU.

IF I COULD PLEASE GET SOMEONE TO GIVE ME HELPFUL INFO, I WILL CONTINUE WITH THIS SITE IF NOT, ENJOY THE FREEDOM I DEFEND FOR YOU.

That's funny Chuck.
Did you happen to notice my location?
Did you happen to see my sig?

Everyone is willing to help you..provided you help yourself a little.

There has been a lot of TBI info posted here. But I don't think you have done any search for it.

Now that you have been provoked into providing at least a little background info we might be able to point you in a specific direction.

Given that it idles and runs fine for the most part, I would recommend going to the site in my sig and check out the FAQ on how to log data.
You will find the software and the plans for the cable needed. It only cost about $6 to make.
Assuming you used a little of that tax free to buy a laptop, you should be fine.

Your system sounds like it is working but you may have parts that are making it operate outside the window that the ECM can compensate for.
So we need data from the ECM to see what it is doing.

The rich..is normally from a cam with valve overlap and the roller rockers may be making noise and causing the ESC/Knock to retard the timing from false knock.

That's funny Chuck.
Did you happen to notice my location?
Did you happen to see my sig?

Everyone is willing to help you..provided you help yourself a little.

There has been a lot of TBI info posted here. But I don't think you have done any search for it.

Now that you have been provoked into providing at least a little background info we might be able to point you in a specific direction.

Given that it idles and runs fine for the most part, I would recommend going to the site in my sig and check out the FAQ on how to log data.
You will find the software and the plans for the cable needed. It only cost about $6 to make.
Assuming you used a little of that tax free to buy a laptop, you should be fine.

Your system sounds like it is working but you may have parts that are making it operate outside the window that the ECM can compensate for.
So we need data from the ECM to see what it is doing.

The rich..is normally from a cam with valve overlap and the roller rockers may be making noise and causing the ESC/Knock to retard the timing from false knock.
Thank you for the reply, I'm currently to deploy on IA orders shortly. You know the tasks at hand at home w/ not enough time to do them all.....

Greatly appreciated
MM1/SS Alford
USN

Yep!!
I have 5 project vehicles and a man cave to finish in my shop.
I'm just to the over the hump mark.
Should be home for Christmas this year.

Good Luck and God Speed.
I couldnt find the link to build the cable for the laptop. Could you give me more specific direction. I looked under your profile and didnt find a link.....


Chuck

BB FI forum (http://www.binderbulletin.org/forums/forumdisplay.php?f=75)

Go here then click on the "sticky" thread that says Fuel Injection FAQ-"START HERE"
Then you will have a screen of links to every step of a TBI conversion.
Just scroll through till you get to the data log thread.

Good info on the stickys, I'll give it a whack. If I cant still figure it out, I'll have a whole mess of Holley, GM, and Edelbrock TBI parts on EBAY to fund the carb swap!

Thanks

Did you verify the voltages of the TPS and MAP sensor, as well as the CTS? Make sure there are no holes in the voltage sweep. These are the most likely ones to throw things off. I've also had luck switching to a 3 wire heated o2 sensor which the TBI computer seems to like for closed loop.

Ian

Good info on the stickys, I'll give it a whack. If I cant still figure it out, I'll have a whole mess of Holley, GM, and Edelbrock TBI parts on EBAY to fund the carb swap!

Thanks

Only if you like going backwards in time and don't wheel that thing.
This is 4X4