What I've done so far and what is still going on.

[85HotAirGN]

When I bought the '85 it wasn't running. I put a new fuel filter in and it cranked right up. I then put new plugs, plug wires, NEW MAF sensor, new air filter, fixed the turbo exhaust pipe and rewrapped and silcone coated. The car runs like a champ except for a few minor things. here they are...

Sometimes when the car is in overdrive, and at a real low RPM, the car will vibrate. It is the same feeling that a clutch car has at to low of an rpm at too high of a gear. the tranny goes through all the gears fine well driving.

It still has at sometimes a surgeing idle as well?!

When driving down the road, I can hear the turbo spooling very well, I just never hear the blowoff valve. On my '87 I always heard the blowoff valve when releasing the throttle, what could be causing this as well? This car when revved at idle doesn't seem to produce much boost and then makes a weird "fart noise" out of the exhaust pipes.?

any ideas are greatly appreciated... Thanks guys.

 

[CaptainInsane-O]

Same scenario as the manual car, RPMs are too low for that engine load so it's on the verge of bogging.

Surging idle, have you cleaned and/or reset the IAC?

Unless you installed one, TR's don't have a BOV... Turbo configuration is probbably why the hot-air sounds different from the 87 & that noise is compressor slam... kindof a chuf, chuff, chuff noise? Car simply isn't going to make boost in neutral, the odd noise is again probably just comressor slam.

 

[turboclam]

Where did you get the new mass air?

 

[85HotAirGN]

Same scenario as the manual car, RPMs are too low for that engine load so it's on the verge of bogging.

Surging idle, have you cleaned and/or reset the IAC?

Unless you installed one, TR's don't have a BOV... Turbo configuration is probbably why the hot-air sounds different from the 87 & that noise is compressor slam... kindof a chuf, chuff, chuff noise? Car simply isn't going to make boost in neutral, the odd noise is again probably just comressor slam.

where is the IAC located and what are the steps needed to clean or reset the IAC?

 

[85HotAirGN]

Where did you get the new mass air?

I bought it brand new from the autoparts store. they had to order it and it took like 3 days to get to Augusta, GA. It's not a refurbished sensor.

 

[85HotAirGN]

bump for help

 

[85HotAirGN]

How does one begin to set the timing on a '85 BUICK Grand National? Thanks in advance guys. I figure I'm close to 10 degrees off.

 

[TURBOTIMMER]

How does one begin to set the timing on a '85 BUICK Grand National? Thanks in advance guys. I figure I'm close to 10 degrees off.

get yourself a cam sensor setting tool from casper's electronics. It's worth its weight in gold. it comes with directions and you should be able to do it yourself. How do you figure you're 10 degrees off?

 

[87geeinn]

Sometimes when the car is in overdrive, and at a real low RPM, the car will vibrate. It is the same feeling that a clutch car has at to low of an rpm at too high of a gear. the tranny goes through all the gears fine well driving.

Sounds like a classic case of a sticking/bad Torque Converter Clutch (TCC) solenoid. This can be tested by driving down the road: With your foot on the gas, tap the brake petal with your other foot. Do the RPMs jump up just a slight bit? If the solenoid is bad, the converter will remain locked and cause the car to bog, especially coming to a stop. It will have the same feeling as coming to a stop in a manual transmission car without pushing the clutch in.


How to set the IAC since you don't appear to have a scantool:

IAC Reset Procedure

Get a decent chip from TurboTweak Home. Do you know what type of chip is in the car now? If it is a stock chip, then it will most likely have a lopey, rough idle since it is in closed loop mode. This is actually quite normal. A lot of aftermarket chips make the car idle in open loop which will stabilze the idle quite a bit provided everything else is in working order.

As stated before: Your car should not have BOV unless one was installed by you or a previous owner. Also, the car shouldn't produce any boost if you rev it up out of gear...which really isn't a good idea to begin with.

Lastly, I would unwrap that downpipe or it will rust and rot away in quick fashion.

 

[bosted86]

the timig is set by the chip. call eric at turbotweak.com and have a chip burned for whatever mod you have.

i second the tcc solenoid. converter is not unlocking. mine did it and i replaced the soleniod.

you will only build boost when there is a load on the engine.

 

[turbobuick87gn]

if your in augusta, ga you need to go see benny. he can put you in the right direction. let me know if you need his number.

 

[85HotAirGN]

if your in augusta, ga you need to go see benny. he can put you in the right direction. let me know if you need his number.

My good friend is a member on here, and owns a '86 GN, his name is John. He gave me Benny's number, I have yet to touch base with him.

My Uncle is incredible with Turbo cars and he has been EXTREMELY helpful thus far.

 

[1chance]

Hi, i dont have a Hot air, but ive been thru my car many times, i live 30miles south of Augusta. Let me know, the weekend is the best time for me. I work in Augusta, off of Laney Walker. 706-726-2662.

 

[85HotAirGN]

Hi, i dont have a Hot air, but ive been thru my car many times, i live 30miles south of Augusta. Let me know, the weekend is the best time for me. I work in Augusta, off of Laney Walker. 706-726-2662.

Oh okay. WOW! small world. I work on Gordon Hwy. Directly across the street from T-Bonz and Deans Bridge Rd. I'll take your number down. Thanks for taking the time to help.

 

[turbofabricator]

There is NO need for a BOV on a hot air car. The turbo blows directly into the intake manifold. The turbo is also a draw-through configuration, so when you let off the throttle, the turbo is trying to suck more air past the throttle blade. The function of a BOV is to relieve the boost in the intake system in front of the throttle body. On an intercooled car, the intercooler, and plumbing from the turbo and to the throttle body fills with boost, and when you close the throttle, that pressure has no where to go, so it backs up through the turbo and back out the air filter causing that "patented" Horse Fart sound.
The sound you are hearing out the tail pips is probably just a glass-pack style muffler. That was the cool sound back in the 60's. Do that in front of an old guy, and he'll love it! ('cept me, of course.)