Newbie help requested. Car stumbles when it tries to get into boost.

You need to adjust your IAC And tps sensors. Iac should be around 30 at idle and tps .44-.46 at idle.


Sent from my iPhone using Tapatalk
Gotcha. Just wondering if I should expect the car to run right


Sent from my iPhone using Tapatalk

No IAC should be right around 15 and a max of 20 at idle. And thats no fan or A/C and at full temp.

You need to start fixing the oblivious first. Get your IAC set and report back.
BTW the video you posted will not show, not sure why.
 
you need to get your car up to full temp and make sure the fan is off. then set it up. If the fan comes on STOP and wait for it to turn off again.
 
Out of curiosity, why is the fan being on a problem


Sent from my iPhone using Tapatalk
Your computer wants to keep your car at a consistent RPM. If the fan turns on your alternator has an extra load on the engine. so your computer will try to compensate by opening up the IAC to keep the consistent RPM.
So when you set your IAC the fan needs to be off.
 
IAC
Stands for
"Idle air control"

For example:
your car wants to stay at 800 RPM. Which is programmed by the computer.

If you put your car in drive your idle air control valve will open to try to maintain 800 RPMs. Same thing happens when the fan turns on.
 
The TPS and IAC may need to be set BUT that's not you stutter problem.

The MAF is a good place to start.
 
Last edited:
How old is your fuel? All the grounds on and tight? Spark plug wires in the right order and on tight? Injector harness plugged on the injectors tight?
 
I'll share a little logic, I hope this doesn't offend anyone as it is not directly addressed to the OP. Just a general observation and I chose to share it in this thread.

If your not in the habit of dropping new engines into Buicks every day................ then I'm not sure why anyone starts a fresh set-up without checking and double checking every single thing over and over!

Oil should be primed, all fluids checked twice. Hoses and fittings tight. Clamps tight. Electrical plugs and splices pulled-on shaken and checked. Vacuum lines traced with your finger to the proper locations and wire tied. Components subjected to high heat should be wrapped, tied safely back, or moved to safer locations. Fuel and alky pressure rise can be checked with power on and applied regulated air pressure. So on, so on, and so on!

And once this is all done.....your still not finished! DO IT AGAIN!!!!!!! Now you should sit around for another week and run through all the other shit you certainly missed in your head. And this definitely means making sure every sensor and computer controlled device should be in place and set as close to perfect as it can be before flipping the key.

I can't even believe how many retards have caused costly time consuming frustrating errors because they just "wanted to get it running". I mean, for Christ's sake! Do you need to get it running because your going to be late for work tomorrow? Do you have to rush someone to the hospital? Even so, let them die!

There will still be somethings that can't be done until the car is running. I understand this more than most. But.....bla bla bla.

I'm done, my rant is over. I'm happy again.:D
 
Last edited:
The other thing that gets me is when an engine is hurt and then repaired without much thought to why it got hurt. If there was an issue with X and that wasn't addressed then the same shit is going to happen again. Wash, rinse, repeat.
 
I'll share a little logic, I hope this doesn't offend anyone as it is not directly addressed to the OP. Just a general observation and I chose to share it in this thread.

If your not in the habit of dropping new engines into Buicks every day................ then I'm not sure why anyone starts a fresh set-up without checking and double checking every single thing over and over!

Oil should be primed, all fluids checked twice. Hoses and fittings tight. Clamps tight. Electrical plugs and splices pulled-on shaken and checked. Vacuum lines traced with your finger to the proper locations and wire tied. Components subjected to high heat should be wrapped, tied safely back, or moved to safer locations. Fuel and alky pressure rise can be checked with power on and applied regulated air pressure. So on, so on, and so on!

And once this is all done.....your still not finished! DO IT AGAIN!!!!!!! Now you should sit around for another week and run through all the other shit you certainly missed in your head. And this definitely means making sure every sensor and computer controlled device should be in place and set as close to perfect as it can be before flipping the key.

I can't even believe how many retards have caused costly time consuming frustrating errors because they just "wanted to get it running". I mean, for Christ's sake! Do you need to get it running because your going to be late for work tomorrow? Do you have to rush someone to the hospital? Even so, let them die!

There will still be somethings that can't be done until the car is running. I understand this more than most. But.....bla bla bla.

I'm done, my rant is over. I'm happy again.:D

I can appreciate your statement but you are NOT speaking to the vast majority of the people that have these cars. Again, I’ve had a couple turbo Buick’s but this is my first new engine for one. A lot of us don’t deal with the engine builds but I will say.... after replacing everything I have replaced including all the harnesses and such, I am very happy that this is all I was seeking help on.


Sent from my iPhone using Tapatalk
 
How old is your fuel? All the grounds on and tight? Spark plug wires in the right order and on tight? Injector harness plugged on the injectors tight?

Fuel is new as the gas tank/lines and all the associated parts have been replaced. I’ll double check the grounds, thanks for your help! The injector harness is the new Casper’s harness and has been double checked. I really appreciate all of everyone’s help here!


Sent from my iPhone using Tapatalk
 
IAC
Stands for
"Idle air control"

For example:
your car wants to stay at 800 RPM. Which is programmed by the computer.

If you put your car in drive your idle air control valve will open to try to maintain 800 RPMs. Same thing happens when the fan turns on.

Thank you for all of the advice! I’ll be working this today! I appreciate it very much!


Sent from my iPhone using Tapatalk
 
It can be a real pita dancing back and forth between the TPS and IAC to get them in sync.
 
I can appreciate your statement but you are NOT speaking to the vast majority of the people that have these cars.
Correct. No I am not. And as I stated above, I wasn't even speaking directly to you. I was just ranting a little. But even for the few............it's just so stupid.
but I will say.... after replacing everything I have replaced including all the harnesses and such, I am very happy that this is all I was seeking help on.
Your doing great! If this was the biggest problem I had after dropping my engine in the first time, I would have thrown a party.
 
Back
Top