1994 Firebird Formula?

[Ring and Pinion]

Hi, new to this site, Ok Ive done a complete transformation from a 1994 LT1 to a 1999 LS1 Trans Am.

Wanting to keep the matching numbers on the engine, I used the original block and intake.

The business that installed the EFI 24x reluctor wheel, engine wire harness, LS1 from a 1999 Corvette ECM, and tune is out of business.

The problem is the idle surges when the engine is warmed up.

The idle will elevate to 1100 rpms when cold.

Turning off the key brings it down, but it starts to surge when it warms up.

Unplugging the IAC keeps it idle at 750 rpm, but it increases the idle intermittently while driving. After a restart, it's back to 750 rpm.

Does anyone know how to retune this on HP tuners?

 

[chuckitall]

Do you have access to a scan tool?

If so, you could see it in real time, like the coolant temp and what the oxygen sensors are doing during the surging problem, etc.

Don't forget simple, obvious stuff, like a vacuum leak, perhaps from the brake booster.

Had a friend who picked up a nice Impala dirt cheap; the old owner thought it had a dead cylinder.

My friend got it home, and it was a dry-rotted vacuum line to the power brakes.

 

[Ring and Pinion]

Do you have access to a scan tool?

If so, you could see it in real time, like the coolant temp and what the oxygen sensors are doing during the surging problem, etc.

Don't forget simple, obvious stuff, like a vacuum leak, perhaps from the brake booster.

Had a friend who picked up a nice Impala dirt cheap; the old owner thought it had a dead cylinder.

My friend got it home, and it was a dry-rotted vacuum line to the power brakes.

Hi, thanks for getting back to me so soon.

I will get that info.