Car stutters when i slowly build boost

[JUSTA3.8V6]

hi guys, im having an issue w my 87 gn. the car stutters badly when i slowly roll into boost but not when i put the throttle to the floor. i have put on a turbotweak chip and 60# injectors this spring and blowoff valve. other than that the car hasnt changed since last summer and i didnt have any issues last year. any help is appreciated!

 

[TLIMITED]

Check cam sensor.

 

[earlbrown]

Do you have an EGR block off plate and a chip that expects the EGR to be functional?


also, what is your setup with chip, MAF, sensor settings, has a spring cleaning been done, etc.....

 

[haywire4130]

Check your blow off valve for leaks, especially if its a cheap ebay one. If you build boost fast it will help hold it closed, if you slowly roll into it it might not be sealing all the way which will leak metered (after mass air sensor) air and will make it run like crapola.

 

[JUSTA3.8V6]

i do have the egr blocked with my power plate but im not sure if my chip is one for a functional egr, i'll have to check. i have an HKS blowoff valve and an LT1 MAF and translator. thanks for the info guys. i have A/T up at fort McCoy for the next three weeks so i will check on those things when i get home.

 

[earlbrown]

If your chip is expecting EGR and it's blocked you will be lean while rolling into it until you get to PE mode .

Under that same case, if you stab it and go straight to WOT, the ECM will fuel correctly (as it doesn't command EGR at that time).



I'm almost positive that TT chips never use EGR. That would be for Eric or someone else to verify.


since you have a BOV, I would make a plate to completely block that off from functioning and see if that fixes the problem.

 

[haywire4130]

^ what he said... Im pretty sure you have to order a TT emissions chip if you want egr to still function. Ive bought several TT chips and dont think I was ever asked if it had egr or not.

I highly suspect the blowoff valve, are you sure its installed correctly (i.e. where did you run the vacuum hose from? If it was after a check valve it could only be getting vacuum, not vacuum and boost). Also did it come with a few different springs/or a knob to adjust preload? (im not familiar with the hks) could just need a little more spring tension to hold her closed.