Basic Hotair Info!

Buick From Hell

Staff member
May 29, 2001
Below are some links to basic buick info! Check 'em out, and anyone else feel free to add to this thread!

Firing order, cylinder & coilpack diagram

Ignition Module wiring diagram

Cam Sensor setting info

ECM connector plugs wiring diagram

Vacuum hose routing with SINGLE wastegate line

Vacuum hose routing with DOUBLE wastegate lines

Turbo Mounting diagram

Trouble codes (This is a link to's section, very comprehensive!)

Fuse Panel diagram and info
(big but easy to read!)

More hose hookups

Intake view

Another intake view

MORE hose hookups


Below is a series of tests to troubleshoot a 'no-start' condition. (I basically reprinted this from a GM troubleshooting flowchart, hopefully it will be of some help!)

Below are links to repair manual pictures to reference from:

ECM Plug
Sensor Plugs

You'll need to get at the ECM and the cam & crank sensors to do some voltage tests. If you have a NEEDLE type voltmeter, it may work better for these tests, as it will visibly "swing" when the sensor switches open & close (IF they're working okay!)

Here goes:

First, test your meter and ground! (see ECM Plug) Check connection A-6, "ign, ECM fuse" for 12 volts. (for ALL tests, BE SURE the negative lead of the voltmeter is connected to a GOOD GROUND!)

#1- (see ECM Plug) With the key off, disconnect the ECM A-B connector. With the positive lead of the voltmeter, probe the B-5 connection (highlighted yellow, this is the crank sensor signal) Crank the engine and watch the should have varying voltage from 1 to 7 volts.
If NOT okay, proceed to #2.
If you ARE seeing correct voltage, your cam & crank sensors are okay, and your coil and/or ignition module may be the problem! You need to loosen the coilpack, and check the BLUE wire for 12 volts, key on. If it DOES have 12 volts, then the problem is likely the ignition module.

#2- now probe the A-11 connection... (highlighted green, this is the cam sensor signal). Crank the should have varying voltage from 1 to 9 volts.
If it's NOT okay, there's no cam sensor signal!

Plug the ECM connector back in, and head for the sensors!

#3 (see "Sensor Plug") Unplug the cam sensor plug. Turn the key "ON" ...On the MODULE SIDE of the plug, probe the "A" wire for voltage, after which probe the "B" wire for voltage. You should have between 5 and 11 volts on BOTH wires.
If you ARE seeing correct voltage, THEN: with the negative lead of the voltmeter, probe the "C" wire, and with the positive lead probe the "A" wire. You should have between 5 and 11 volts. Note the results, then REPEAT THIS TEST WITH THE CRANK SENSOR PLUG!

If ANY of the sensor plug tests FAILED, you have a probably ignition module problem...
If ALL the sensor plug tests PASSED, then PLUG IN the sensor plugs, and proceed:

#4. Test the cam sensor: Probe the "B" wire of the cam sensor, then crank the engine and watch the meter. You SHOULD have varying voltage between 1/2 and 9 volts. REPEAT THIS TEST WITH THE CRANK SENSOR!

If either sensor fails this test, then it's possible that sensor is bad! If they PASS this test, it's likely the ignition module, or the connections TO the ignition module are bad)

Hope this makes sense!


Thanks for posting this! I am putting my car back together this weekend and this will help alot.


Could you post a link of the intake? Hopefully this will show which of the ten bolts go where, I am lost trying to put this back together.

I don't have a pic that would help you, but if anyone does, they can e-mail it to me, and I'll get it on the net and put a link to it above!


Thanks guys this will help tremendously!

Here's a suggestion...

If more people spent some time reading and figuring out how and why things work like they do on these cars, there would be less headaches and throwing "more mods" and parts at the problems instead of replacing or fixing the little problem that is causing everything else to go haywire!!!

Each sensor and adjustments to those sensors(the ones that can be adjusted) affects something else...If you know how all these parts and sensors relate to each other, everyone wouldn't be as frustrated and pissed off at their cars as some have been lately...


OH YEAH...Go here for more info... read EVERYTHING!!! Regardless if it's for the hotair cars or the 86/7 Intercooled cars...The principles are the same for either, just some parts are relocated in different positions...Everything else works the same...

Enough of my ranting...
How about Electrical Nightmare.

How about a good diagram of the electrical connections. I just fell into A 84 gn with a rebuilt engine was told that it would only idle. The previous owner had sent the car to three different shops and on it is fried. Nobody knows what they were doing . I need a starting point. How about a good Turbo Manual also???
Russell in Western Central Florida
If you have any questions, try posting them in a seperate thread...

This thread that you are posting in is just a general info thread meant to stay at the top of the page, i.e. basically what is called a "sticky"

You will probably also get more responses in a separate thread as well...

Start a new thread and I'll try to give you some answers there...There are a few things to check that we can walk you through the procedures...Also go to and read through everything...Most, if not all, of the info that is being told here, is already over there in one form or another...

As I said, start another thread and I'll try to help you out some more there...

Used this thread and got all my sensors working. Thanks.
On the crank sensor (if your new at it like me) be careful that the braket goes all the way on the guide pin for the timing chain cover. I broke two brakets before I finally drilled the hole out a little with a 1/4" drill.
I also broke a magnet off one sensor because I put it on and turned the crank before I loosened the sensor in the bracket. I guess I thought it was a factory preset. Someone had a picture that helped me a lot (Buick from Hell possibly)
Thanks for info

:eek: I have been dying over here no one I know knows crap about Gn's no less anything about the Hot Air cars. This has helped me tremendously I am going to change right now and fix that mess of vacumn lines under the hood of my car to this point I have been guessing on how to put it back together thanks again.

Now only if I knew how to change the Heater core without having my hairfall out.

85' GN #77 of 2102 all stock (For Sale) sharp car in and out rebuilt engine 65,600 orig. miles

75' Corvette Stingray 355 w 6-71 Littlefield Blower Wieand manifold dual carter 750's th-400 3500 stall 3.90 rear much more!!
Just a couple of pics of basic sensors and locations.

Thanks BFH for posting this info....

I probably knew all of this when it was posted - but it's been 2 years since I've even looked at a hotair car.