Tuning a 93 3.4 Firebird

[60dgrzbelow0]

Robert... Without "Tinkering with the Tuning" side of this conversation... have you ever encountered situations where the stalling problems are related to some other mechanical or vacuum problem that can get lost in the crowd of all the computer manipulations issues? The Short Form W-2 question being... Can the problem be explained or investigated in other areas?

[tkoforpresident]

Robert... Without "Tinkering with the Tuning" side of this conversation... have you ever encountered situations where the stalling problems are related to some other mechanical or vacuum problem that can get lost in the crowd of all the computer manipulations issues? The Short Form W-2 question being... Can the problem be explained or investigated in other areas?

It better not be, at least in my case. I replace vacuum hoses galore with brand new ones as well as sensors and gaskets etc. Theres no way i think this is a strictly "mechanical" issue. I also would not worrry about your build, which I know you probably do from time to time, the comp 260H is not as radical as you might think. In fact, the reason why i went with John's radical camshaft on the second build, was because my 260H was not loping at ALL.

Try to figure that one out because I couldn't and i spent weeks asking around as to what exactly made a camshaft that was supposed to lope "note lope at all".

if you want video proof, here ya go.


keeping in mind i have a flowmaster exhaust/headers you can hear how pathetic this idle is!
This was how my car sounded after the 260H install and right after i had my y pipe welded at a shop because it was leaking like the titanic.

At that point (when i found the milkshake oil and knew i had to rebuild it anyways) I told John to hook me up with the most wicked thing he's ever concocted. What he gave me was a beast but he told me it probably wouldn't run well on a stock tune.

[60dgrzbelow0]

I also would not worry about your build, which I know you probably do from time to time... In fact, the reason why I went with John's radical camshaft on the second build, was because my 260H was not loping at ALL. Try to figure that one out because I couldn't and I spent weeks asking around as to what exactly made a camshaft that was supposed to lope "note lope at all". At that point (when i found the milkshake oil and knew i had to rebuild it anyways) I told John to hook me up with the most wicked thing he's ever concocted. What he gave me was a beast but he told me it probably wouldn't run well on a stock tune.

Ouch...Max... "Child...You CUT me to the QUICK! Take Thy Beak...from out my Heart!!!" You are right... I actually DO worry about 'The Build' I'm most concerned with...and far more often than all my "Hypnotic Meddling in the Mechanical Affairs of Others" might imply.

My question to Robert was not meant to cast any aspersions on either your thoroughness or your understanding... but more in dread of my running into these same problems...with "My Own Build" as you pointed out... when the time comes for it to be my turn to suffer the Turn of The Ignition Key... Forgive me... Please!



As for the "Lack of Lope" in the 260H you tried... I actually think it sounded fairly decent...considering that your idle RPMs seemed a bit higher than the usual 600 RPM the engine languishes at. If my engine sounds even half as good as yours does (did) in that video... I will be VERY pleased!

And now that you have taken a swing at my chin...please help me up off the ground with some information about whether you pulled your engine (and or Xnsmission) out through the top of the car ...or "K-Framed" it from the bottom. If there is a separate thread about this matter ...specifically 60* Engine Pulling for the 4th Gen F-Bodies...I'd like to read up on it...

[IsaacHayes]

Does the FPR have a vacuum line? If you disconnect that does the FPR go up? If so then yes that's how stock works...

And that's not my formula... lol just applying the differences to existing values rather than use more complex formulas and data to arrive at the same #. If we didn't have the factory values and know what they represented, then we couldn't do it so easy. But since we do, it's the quickest way.

2000+ 3x00 FPR's are at 55psi so 60 should be ok... (anyone remember if it's 55 WOT or at idle? I forget which they are measured at).

[tkoforpresident]

Does the FPR have a vacuum line? If you disconnect that does the FPR go up? If so then yes that's how stock works...

And that's not my formula... lol just applying the differences to existing values rather than use more complex formulas and data to arrive at the same #. If we didn't have the factory values and know what they represented, then we couldn't do it so easy. But since we do, it's the quickest way.

2000+ 3x00 FPR's are at 55psi so 60 should be ok... (anyone remember if it's 55 WOT or at idle? I forget which they are measured at).

Yes it has a vaccum line going right to it. In fact, the correct way of setting fuel pressure is to have the engine running, disconnect the vaccum hose (put your thumb over the hole) and set your HIGHEST desired psi. So i would follow that procedure to set it to 50 psi or whatever i want.

Isaac, is my determined BPC of 193 correct ?? ( 19lb injectors @ 47psi with the 3.4 block) ??

[robertisaar]

Robert... Without "Tinkering with the Tuning" side of this conversation... have you ever encountered situations where the stalling problems are related to some other mechanical or vacuum problem that can get lost in the crowd of all the computer manipulations issues? The Short Form W-2 question being... Can the problem be explained or investigated in other areas?

it can always happen, but if it comes up after installing a radical cam, i'm always inclined to think that's the issue. but all it takes is missing one major vacuum line or something similar and you can spend hours or days on it and never find what's wrong. basically, a rebuild gone bad...

tko: why did you jump jump back to 193? you had it right when you said 202...

isaac: yes the pressure that's dialed in is what applies at WOT, using the method that TKO described.

[tkoforpresident]

Ouch...Max... "Child...You CUT me to the QUICK! Take Thy Beak...from out my Heart!!!" You are right... I actually DO worry about 'The Build' I'm most concerned with...and far more often than all my "Hypnotic Meddling in the Mechanical Affairs of Others" might imply.

My question to Robert was not meant to cast any aspersions on either your thoroughness or your understanding... but more in dread of my running into these same problems...with "My Own Build" as you pointed out... when the time comes for it to be my turn to suffer the Turn of The Ignition Key... Forgive me... Please!



As for the "Lack of Lope" in the 260H you tried... I actually think it sounded fairly decent...considering that your idle RPMs seemed a bit higher than the usual 600 RPM the engine languishes at. If my engine sounds even half as good as yours does (did) in that video... I will be VERY pleased!

And now that you have taken a swing at my chin...please help me up off the ground with some information about whether you pulled your engine (and or Xnsmission) out through the top of the car ...or "K-Framed" it from the bottom. If there is a separate thread about this matter ...specifically 60* Engine Pulling for the 4th Gen F-Bodies...I'd like to read up on it...

No worries Bob

I didn't remove the engine from the vehicle so i cannot help you in that regard. All work (both times) was done with my back bent like a pipe cleaner pixy stick and reminding me for days afterward.

[tkoforpresident]

it can always happen, but if it comes up after installing a radical cam, i'm always inclined to think that's the issue. but all it takes is missing one major vacuum line or something similar and you can spend hours or days on it and never find what's wrong. basically, a rebuild gone bad...

tko: why did you jump jump back to 193? you had it right when you said 202...

isaac: yes the pressure that's dialed in is what applies at WOT, using the method that TKO described.

oops, i meant to say 202, my mistake. So I will go ahead figure out what BPC will be for 50psi etc. In fact, maybe i should make a chart dictating all of the BPC values at each given psi (from 43.5-60) so if i ever feel like changing fuel pressure i can just reference the chart and set my bpc to it's proper #

[robertisaar]

In fact, maybe i should make a chart dictating all of the BPC values at each given psi (from 43.5-60) so if i ever feel like changing fuel pressure i can just reference the chart and set my bpc to it's proper #

not a bad plan.

[tkoforpresident]

As for the "Lack of Lope" in the 260H you tried... I actually think it sounded fairly decent...considering that your idle RPMs seemed a bit higher than the usual 600 RPM the engine languishes at. If my engine sounds even half as good as yours does (did) in that video... I will be VERY pleased!

well my car is (in the video) and always has idled around 1,000 rpm. but i thought that was normal...


just to keep things in perspecitve, the video of John's camshaft is ALSO at 1,000 rpm idle.

When i have a minute i will get some clips from youtube of other 3.4's with the 260H that sound pretty nasty and 10x better than the clip i just showed you.

[tkoforpresident]

btw, are there any threads on this site you guys can think of (off the top of your head) that has many of these "beginner" tuning issues or info having to do with this kind of tuning that i can read up on. That way i can keep learning without asking questions that have been gone over many times before.

thx

[robertisaar]

brad has a tuning article going on somewhere... i've added a bit to it, but it's always tough to find...

[tkoforpresident]

thx i'll look around

[tkoforpresident]

hmm.. can't seem to find it.

[robertisaar]

here it is:

http://60degreev6.com/Computer/Tuning/OBD1_Tuning