intermittent boost problem on 96 k2500hd

[matt-max]

my 96 6.5td is behaving badly

it runs great showing up to 12# boost and accelerating until suddenly the gauge swings down to 2# and it slows and smokes like crazy then back to 12 a bit later then 2 again, etc.

its running the tts ecm with bd 4" and afe filter

any ideas?

thanks
matt

[rjschoolcraft]

Any codes? Maybe the boost solenoid is shutting down boost?

[markelectric]

Sounds like a problem I fought for a while. Save yourself a lot of hassle and put a turbomaster on it. After I did to mine I have NEVER had any questions about my boost. I even threw away the old vacuum pump by using a 93 serp belt.

[Turbine Doc]

Matt see if you can get someone to read your codes and post them, I'm pretty sure auto zone can read them but usually they can not really tell you what to do with them though. Could be multiple causes. in the meantime trouble shoot the vacuum circuit. tee in with a vacuum gauge to see how much vac from the pump, then monitor the vac to the wastegate while driving you could be having some problems in that area, check integrity of the vacuum hoses/tubes you may have a split that only shows intermittently at a certain vibe when at a specific speed. Check electrical connections to sensors intermittent short or corrosion at a sensor could also be culprit. really too many to guess at why get some codes so we can have a better idea of how to help.

[matt-max]

turbo-master already on the way. it is the mechanical type not the plug in type. any difference?

no codes showing i thought because no check engine light. will have it read anyway

thanks
matt

[markelectric]

I did not know there was a plug in type. The mechanical type removes all the vacuum and electrical variables. Matt I see you are in Bloomington, who does your diesel work for you? I am in Columbus, and have to go tward Seymour for a dealer employee that works out of his garage.

[rjschoolcraft]

The Turbo-Master is a mechanical exhaust back pressure regulator that allows you to adjust boost by adjusting spring tension or compression. The "plug-in type" is John Kennedy's electronic boost control for the 94 and up trucks. Rather than removing the PCM control and the associated advantages, this works with the PCM and existing electronics to give you adjustable boost control.

I don't understand the growing desire among folks on this page to trash the electronics on the newer trucks...electronic to mechanical inj. pump swaps, Turbo-Masters on electronic trucks, pulling ABS fuses and placing black tape over lights on the dash. It doesn't make any sense to me.

Matt-max, you have a component failing. If you troubleshoot and find it, you can replace that component...probably the boost solenoid for about $30...and have the system functioning normally again in about 10 minutes.

[ 10-13-2003, 05:04 AM: Message edited by: ronniejoe ]

[matt-max]

thanks all, esp. fellow southern indiana dwellers

we do our own work on them unltil we're stumped then post it here then tell the service manager at the gmc dealership in town (curry) what to do if we dont have time or tools to do it

too expensive to have stuff repaired by others most of the time

will try the solenoid replacement'
thanks again
matt