87 Turbo T, high idle/driving hesitation problems/stumped????

[gunzandgearz]

Ok Ed Ill try to give you the best advice I can as I don't claim to be the best wrench on the planet but we do a lot of driveability diagnosis in my shop, so here goes. First off do what most of these guys have told you and get some sort of a scan tool as I hate throwing parts at stuff,you would be better off spending your money on the scanner, and finding the root cause of the problem and buying one or two parts and having the scanner for life for future problems,instead of buying five parts and still not fixing it.The filter,plugs,wires, coil,can pretty much be ruled out as the problem because if car runs good at high rpm the problem would only get worse if any of these were causing the problem.The injectors if plugged or dirty can cause tip in problems and misfires at idle and off idle and still run ok up top as pressure increases,but still wont cause high idle condition.As a lot of these guys have already recommended look for vacuum leaks, IAC {need bidirectional scantool for this}to check actual operation and and also need bidirectional scanner for maf operation as you can check it for proper airflow while driving in second gear and checking for proper airflow of sensor.Good luck, by the way most likely cause of your problem imo is vacuum issues as this will cause iac to act screwey and cause hi idle.

 

[Ed Salsbury]

Ok Ed Ill try to give you the best advice I can as I don't claim to be the best wrench on the planet but we do a lot of driveability diagnosis in my shop, so here goes. First off do what most of these guys have told you and get some sort of a scan tool as I hate throwing parts at stuff,you would be better off spending your money on the scanner, and finding the root cause of the problem and buying one or two parts and having the scanner for life for future problems,instead of buying five parts and still not fixing it.The filter,plugs,wires, coil,can pretty much be ruled out as the problem because if car runs good at high rpm the problem would only get worse if any of these were causing the problem.The injectors if plugged or dirty can cause tip in problems and misfires at idle and off idle and still run ok up top as pressure increases,but still wont cause high idle condition.As a lot of these guys have already recommended look for vacuum leaks, IAC {need bidirectional scantool for this}to check actual operation and and also need bidirectional scanner for maf operation as you can check it for proper airflow while driving in second gear and checking for proper airflow of sensor.Good luck, by the way most likely cause of your problem imo is vacuum issues as this will cause iac to act screwey and cause hi idle.

Hey thx very much GunsGearz, I appreciate you and everyone else's time and experience on this , yes, I've decided I am ordering a scan master to help me out, I'll check for vac leaks also, there's a Greedy blowout valve set about 1/2 way on it from previous owner, so I don't know what he has in this thing, chirps 2nd gear loudly each time even at normal throttle so prob chipped it and then some, I'll keep u updated, take care bud, Merry Christamas to u and family

 

[gunzandgearz]

Thanks and merry Christmas to you and your family too.

 

[Chuck Leeper]

Take it to Jack Cotton in Spfld, MA.

 

[Ed Salsbury]

Problem solved
Thank you all for your suggestions and help. For now, I've solved the no start problem, thx to your advice, I checked all fuses and then I jumped out fuel pump primer wire to V+ on alternator and sure enough, fuel pump activated. So now I'm going to replace the fuel pump relay on pass side inner fender well, although I did post a question as to which is which, fuel pump relay vs AC compressor relay as diagrams contradict one another.

Next I'll get back to the hesitation issues to tackle, I've ordered my Scanmaster 2.1 so that should help me solve that problem. Thx again. Ed

 

[GNRick]

If the stock oil pressure sender is hooked up then the fuel pump will still work even if that relay on the fender fails. For more info see the Vortex Buick site.