Bogs for a second and then takes off

[secondchance]

Originally Posted by Johnny5

"It appears that Z owners that is having the problem have in commons are: 1) the secondaries eliminated
2) Haibeck chip

How about the injectors. What injectors do you have currently installed. I have talked to Marc in regards to this concern and he has 2 1990 that are doing the same thing as well. He suspecting injectors. I'm going to data log and check the car out this weekend. Will let you know what I find out. We can make some changes to the fuel trim if need be."

I have a 1991 (27k miles) that is all stock so I did not delete the secondaries or have a chip. (The secondaries won't open up either) it currently has the stock injectors as well and I noticed my car bogs or surges when cold too! I'll see if it does this after changing the injectors. I just ordered the obd2 to obd1 conversion so i can see if I get any codes from my scanner.

Assumption that secondary removal and Heibeck chip causes stumble is not true. I had my secondaries removed and run Heibeck chip. I had stumbling problem but the issue turned out to be O2 sensors. Replacement of O2 sensors fixed the problem. After another couple of months stumbling returned. This time the cause was TPS going bad. MAP sensor going bad will cause the car to stumble also. Bear in mind that our cars are 20 plus years old resulting in some sensors giving up the ghost.

Done correctly, secondary removal and Heibeck chip to run both injectors are worthwhile modification.

In your situation, with OEM injectors, I'll bet your injectors are failing. I've seen enough ZR-1s with OEM injector failures.