Bad hesitation on acceleration from a stop.

[mb10190]

87 Grand National Running 93 octane

Hello, need help with this issue I am having after installing all new mods...
Mods are

5.7 TT chip 60# injectors set for 18# boost
MAF Translator LT1 MAF
GN1 72MM throttle body, Plenum and spacer
HPT 6262 Turbo with 45mm external waste gate with 14# spring with manual boost controller.
And supporting fuel system fuel pump and lines
3" down pipe and full exhaust.

I have set fuel pressure, TP sensor and all the dip switches in the Translator per instructions that came with the TT Chip.
I'm at a loss as to why it hesitates when I am pulling away from a stop. (Runs great after that)
If it were a carburetor I would replace the accelerator pump... LOL

So, any help with this would be greatly appreciated.
Thank You
MB

 

[John Larkin]

Check your connection between the MAF and the translator. As I recall, the pink wires need to line up but you can plug it in backwards and it will run. I wish it was only one way but it isn't.

Also, did you install a high stall torque converter at the same time? Not likely the stock converter will allow that turbo to spool up and make power down low.

 

[TurboBob]

when you ordered the chip, did you specify that large throttle body?

Bob

 

[Chuck Leeper]

What does the PL log show?

 

[mb10190]

Converters next mod on the list. I will check that connection...
Ty
MB

when you ordered the chip, did you specify that large throttle body?

Bob

No, I did not say anything about the 72mm TB and plenum... Why you ask? Humm
Ty MB

 

[js402]

Is the car under load? If so start checking ignition components ts then your fuel pressure

 

[1986 Buick GX1]

This is my take on it.
At 10% throttle opening a 72mm tb will have more airflow than a 62mm.
If the chip isn’t programmed for the increased airflow there may be a lean condition because the computer sees the same TPS voltage and thinks it’s still a 62mm.

I’m sure TurboBob will have more details.

 

[mb10190]

This is my take on it.
At 10% throttle opening a 72mm tb will have more airflow than a 62mm.
If the chip isn’t programmed for the increased airflow there may be a lean condition because the computer sees the same TPS voltage and thinks it’s still a 62mm.

I’m sure TurboBob will have more details.

That makes sense.

 

[TurboBob]

Thats a good explanation. I think the stock throttle is 57mm, and the difference is the ratio of the squares (for the nerds following along)

I would consider trying the stock throttle body as a test. There is no real power in the big throttle, and you can kill the transmission with too much power at really small throttle angles.

Bob

 

[Chuck Leeper]

There is no real power in the big throttle,

That's what I've seen, too.