kompressorgolf
New member
Hey all, first post, and its gonna be a doozy. Ive read hundreds of threads in the search looking for some answers. i think im getting close. but looking for some insight. here goes.
I bought 93 TY 0634 in october last year, after lusting since i was a boy. pretty clean truck, im in love. I drove the truck 12 hours home fron denver to bozeman MT. trouble free. i noticed almost right away that it wasnt boosting what it should. So i began the process of going through everything. i found 5 spark plugs one brand and 1 another brand, and one was finger loose (6). replaced with UR6 and Taylor 8.8 with correct boots for syty. MSD cap and rotor. That didnt help things, so i started looking into boost control. i got a hand boost tester. hooked up the wastegate to it, wastegate starts cracking at 4-5 psi and full open at 8, and doesnt bleed down. checked the pretension just to be thorough. then i realize the solonoid doesnt look right. turns out the top nipple that supposed to go to the wastegate actuator, is broken off clean, and PO took the filter off and put the actuator line on the filter nipple.... Im thinkin hell yes, got it. i work for GMC and promtly ordered a delco replacement. Bam no luck. tested the relay, all good. truck runs pretty awesome mostly. What its doing is you stab it, it takes off, boost shoots to 8-9 then acts like it hits a program fault and drops to 4. If you stay in it, it will shoot to 14-15 like it should but then fall back to 4-5. so i realized that i need to see what its doing. i ordered the scanmaster G. Then next up, i was getting a puff of blue smoke on warm restart if it sits for a hour or more, so i decided to tear into it and do valve seals and further explore any other issues. I did all new SM vacuum line kit, tested EGR system checked timing connector unplugged, i didnt verify if balancer shifted tho. thats a next step.. did a boost test, and didnt find shit. throttle shaft but not enough to be detrimental. Intercooler system is fine, even has a second heat exchanger. pump is wired on all the time. Next during some testing i tried a boost launch to see if it would build more boost, it didnt, however it did spiral shatter the output shaft in the transmission and destroy the planetaries and pump in the process. rebuilt the trans, beefed up a bit, nothing crazy. new stock converter. after that i just drove the truck casually for a bit. trying things here and there. I tested the wire from the ecu to the boost solonoid and have good continuity and power at the plug on the orange. unplugging it doesnt change anything. So i thought, well ill get the turbotweak for a stock truck with 3 bar and 91 tune. (forgot to mention im getting very minimal knock) maybe up to 3 on a shift. I installed the chip and map sensor. and boy did the drivability clean up, idles better etc. i drove it for a day without boost just so it could learn. then i let it eat. It hit a max of 3..6 psi of boost. i took the exhaust off and verified the cat is clear, i can see through it all the way across. But now with the chip installed it doesnt spike at all. it just hits about 4psi and stays there. no up and down etc. it feels waaaay cleaner driving but just no boost. turbo is tight, no play compressor housing is perfect no chips or knicks on the fins. I did a compression test, and its 155 across all 6. on a luke warm engine. i want to get it right, as it should be i dont want to change to aftermarket stuff, like forge wastegate etc, or manual boost control, i just want it to work as it should at least to start. Im starting to think the ecu may be bad i just dont know what else to do. I bought a upper and lower intake set, a 160 thermostat and a ac delco ignition module to put in all at the same time. i was thinking maybe my lower intake gaskets are blown into the lifter galley, and thats where all my boost is going, shit i dont know! any insight would be helpful. Even with all the headaches, i love my white/white Phoon!
I bought 93 TY 0634 in october last year, after lusting since i was a boy. pretty clean truck, im in love. I drove the truck 12 hours home fron denver to bozeman MT. trouble free. i noticed almost right away that it wasnt boosting what it should. So i began the process of going through everything. i found 5 spark plugs one brand and 1 another brand, and one was finger loose (6). replaced with UR6 and Taylor 8.8 with correct boots for syty. MSD cap and rotor. That didnt help things, so i started looking into boost control. i got a hand boost tester. hooked up the wastegate to it, wastegate starts cracking at 4-5 psi and full open at 8, and doesnt bleed down. checked the pretension just to be thorough. then i realize the solonoid doesnt look right. turns out the top nipple that supposed to go to the wastegate actuator, is broken off clean, and PO took the filter off and put the actuator line on the filter nipple.... Im thinkin hell yes, got it. i work for GMC and promtly ordered a delco replacement. Bam no luck. tested the relay, all good. truck runs pretty awesome mostly. What its doing is you stab it, it takes off, boost shoots to 8-9 then acts like it hits a program fault and drops to 4. If you stay in it, it will shoot to 14-15 like it should but then fall back to 4-5. so i realized that i need to see what its doing. i ordered the scanmaster G. Then next up, i was getting a puff of blue smoke on warm restart if it sits for a hour or more, so i decided to tear into it and do valve seals and further explore any other issues. I did all new SM vacuum line kit, tested EGR system checked timing connector unplugged, i didnt verify if balancer shifted tho. thats a next step.. did a boost test, and didnt find shit. throttle shaft but not enough to be detrimental. Intercooler system is fine, even has a second heat exchanger. pump is wired on all the time. Next during some testing i tried a boost launch to see if it would build more boost, it didnt, however it did spiral shatter the output shaft in the transmission and destroy the planetaries and pump in the process. rebuilt the trans, beefed up a bit, nothing crazy. new stock converter. after that i just drove the truck casually for a bit. trying things here and there. I tested the wire from the ecu to the boost solonoid and have good continuity and power at the plug on the orange. unplugging it doesnt change anything. So i thought, well ill get the turbotweak for a stock truck with 3 bar and 91 tune. (forgot to mention im getting very minimal knock) maybe up to 3 on a shift. I installed the chip and map sensor. and boy did the drivability clean up, idles better etc. i drove it for a day without boost just so it could learn. then i let it eat. It hit a max of 3..6 psi of boost. i took the exhaust off and verified the cat is clear, i can see through it all the way across. But now with the chip installed it doesnt spike at all. it just hits about 4psi and stays there. no up and down etc. it feels waaaay cleaner driving but just no boost. turbo is tight, no play compressor housing is perfect no chips or knicks on the fins. I did a compression test, and its 155 across all 6. on a luke warm engine. i want to get it right, as it should be i dont want to change to aftermarket stuff, like forge wastegate etc, or manual boost control, i just want it to work as it should at least to start. Im starting to think the ecu may be bad i just dont know what else to do. I bought a upper and lower intake set, a 160 thermostat and a ac delco ignition module to put in all at the same time. i was thinking maybe my lower intake gaskets are blown into the lifter galley, and thats where all my boost is going, shit i dont know! any insight would be helpful. Even with all the headaches, i love my white/white Phoon!
