Re-tuning for warmer weather?

T

"Turbo-T"

V6 on steroids
Joined
Jan 10, 2007
Today it was right at 100 degrees. I'm going down the road, a/c on, alky on, in full boost (25 lbs) and the timing no the chip is set at 25/23. There's a mix of 93 octane and 110 octane in the tank, about 1/4 tank according to my fuel gauge.

Despite the car running well and accelerating well, I start seeing some knock (0.7) on the Scanmaster, then the Caspers alarm goes off almost immediatley with the Scanmaster showing 2.3 on the KR. Quickly glanced at my wideband and it's in the 14-15's at WOT. Yet I can hit the prime button on my alky controller and watch the wideband numbers change to the upper 10's/lower 11's. Obviously this isn't right.

I've heard of people tuning these cars for warmer weather and then for colder. Do turbo Buicks run leaner when it's hot? Should I just add fuel in all gears? How much? I have a Turbo Tweak chip. Last thing I want to have to do is change hg's or worse grenade the engine.

Thanks in advance.
 
87Regal3.8SFI said:
Today it was right at 100 degrees. I'm going down the road, a/c on, alky on, in full boost (25 lbs) and the timing no the chip is set at 25/23. There's a mix of 93 octane and 110 octane in the tank, about 1/4 tank according to my fuel gauge.

Despite the car running well and accelerating well, I start seeing some knock (0.7) on the Scanmaster, then the Caspers alarm goes off almost immediatley with the Scanmaster showing 2.3 on the KR. Quickly glanced at my wideband and it's in the 14-15's at WOT. Yet I can hit the prime button on my alky controller and watch the wideband numbers change to the upper 10's/lower 11's. Obviously this isn't right.

I've heard of people tuning these cars for warmer weather and then for colder. Do turbo Buicks run leaner when it's hot? Should I just add fuel in all gears? How much? I have a Turbo Tweak chip. Last thing I want to have to do is change hg's or worse grenade the engine.

Thanks in advance.
Click to expand...

Cold weather would make you lean. Hot weather rich. Sounds like your fuel pump is laying down. Running around on 25psi boost puts them through hell. Time to drop the tank.

The alky prolly saved those hg's. I would stay out of it.
 
TurboBuRick said:
Cold weather would make you lean. Hot weather rich. Sounds like your fuel pump is laying down. Running around on 25psi boost puts them through hell. Time to drop the tank.

The alky prolly saved those hg's. I would stay out of it.
Click to expand...


agreed, before my wideband tracking chip i had to add about 15-18% fuel in the cold months compared to the 80s-90s in the summer. Sound like a bad fuel pump.
 
Well that's a bummer. I actually replaced this pump 2 years ago.

I did however make a few passes at the track back in early July and didn't have any issues with fuel problems.

Are Walbro 340's not designed to handle the amount of boost I'm running?
 
Also make sure that your fuel pressure regulator isn't the culprit. they aren't entirely infallible.
 
Thanks fellas.

Well you are right, there's definitely a fuel pressure issue. :mad:

I took the car out once more and carefully brought it up to boost. I have an Autometer electric fuel PSI gauge beneath my boost gauge on the A pillar.

The fuel PSI rises 1 psi per 1 psi of boost...until it gets up to around 5-6 PSI....the fuel psi hits 44-45 and then starts to drop off. The wide band confirmed this as the numbers went from 11 to 12.

The fuel psi regulator is an Accufab from full throttle speed and the pump is a Walbro from gbodyfarts I bought from them in Feb 2008, right before everyone started complaining about them. So I don't know if I am another unlucky one to have gotten a defective pump that's now starting to show it's colors or if the FPR is to blame...is there any way I can isolate them to determine the guilty culprit?
 
Id get a walbro from racetronix. Ive had good luck with them. The guys that sell the 169 walbros seem to have them fixed after that whole ordeal but I like the racetronix walbro 340s for a basic low 11 to high 10. A supra pump is also a good replacement.
 
87Regal3.8SFI said:
Well this sucks. So what would you recommend for a pump?
Click to expand...

If it were ME, with your mods, I'd go with the Walbro 340 from Racetronix... I'm sure the basic Walbro 255 would be adequate, but if your gonna' do it, it's probably worth the extra $10-$20 (if that?) for the 340. Having said that, you 'could' do the denso supra pump thing, but IMO, it's overkill and un-necessary at your level... costs considerably more, requires special harness from racetronix, slight mods to make it fit, and the (albeit low, but has been observed by some) possibility that you won't be able to get your fp LOW enough due to high flow rate of the denso and relatively low return line capacity in our cars.... I'd go walbro... 'fo sho'.. :wink:
 
Oh... maybe it is....:redface: but then, are the the old Walbro 242, 262, etc's 255 gph also? or are they maybe 190 gph (or is it liters/hr?).... anyway... regardless, I'd go Walbro 340 from racetronix... in agreement with JD.... hope I didn't add any confusion... :redface::smile:
 
bmackinnon said:
Oh... maybe it is....:redface: but then, are the the old Walbro 242, 262, etc's 255 gph also? or are they maybe 190 gph (or is it liters/hr?).... anyway... regardless, I'd go Walbro 340 from racetronix... in agreement with JD.... hope I didn't add any confusion... :redface::smile:
Click to expand...

Looking at racetronix site, I answered my own confusion.... yup, the 242 is 190 L/hr, and starting with the 307 and up, they are 255 L/hr...
 
Thanks for the clarification/recommendations.

I can only hope this will be the last time I have anymore fuel pump issues if I buy one from Racetronix. I didn't think my current pump fell into the "premature death" Walbros. As said it's not but 2 years old and probably not even 4,000 miles on it, if that.
 
87Regal3.8SFI said:
Thanks for the clarification/recommendations.

I can only hope this will be the last time I have anymore fuel pump issues if I buy one from Racetronix. I didn't think my current pump fell into the "premature death" Walbros. As said it's not but 2 years old and probably not even 4,000 miles on it, if that.
Click to expand...

Fuel pumps will always fail. That's been proven time again. It's the nature of the beast. The important thing is that you caught it before it took out a hg. You can pat yourself on the back for being on top of things.
 
TurboBuRick said:
Fuel pumps will always fail. That's been proven time again. It's the nature of the beast. The important thing is that you caught it before it took out a hg. You can pat yourself on the back for being on top of things.
Click to expand...

+1 I drive my cars alot and Ive had more then a few fuel related issues :rolleyes: 99% of the time it was always caused by the fuel pump :mad:
 
TurboBuRick said:
Fuel pumps will always fail. That's been proven time again. It's the nature of the beast. The important thing is that you caught it before it took out a hg. You can pat yourself on the back for being on top of things.
Click to expand...

I understand anything man made is guaranteed to fail, just that I've had vehicles with in tank pumps that I drove for a long time w/no issues and this one makes it barely 2 years and dies. Plus there seemed to be a rash of bad Walbros after I installed mine, though I am almost sure mine was a 340 model and not one of the famous F(ailure)2000169 ones.

But yes I am thankful i caught this in time and thankful the board members were of a big help.

One last ? though....

If my pump is dying, will it eventually get worse and worse to where you can't drive the car at all? B/C I'm going to have to drive it one last time (we're in the process of a move)
 
It's the big boost that kills the pump. Back in the day we ran what 17-18 psi boost? Now with alky, the pump has to work allot harder.

I would say your ok to drive it. Just stay out of the boost.
 
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