New to Cars - Engine turning off

[Jericho]

Hello fellow GN lovers.
I recieved an '87 from my dad and I am having a hard time narrowing down what needs to be fixed. I jave read many posts on this site but still haven't located the root cause. Let me preface this that 1, I am very new to working on my own cars and 2, this car sat fairly stagnant for 2 years.

At first I had to power brake the car in order to get it to my house. While I had my foot on the gas everything was fine. It seemed when it got down below 1k rpm it would die. When I really looked into it, it seemed to do it more when the engine was warm. My dad told me he had this issue and it was the MAF sensor. Changed that. Didn't stop. I also changed the spark plugs and wires because I thought it sounded like a firing issue. Then I noticed the lights dimming when I removed our trickle charger. I took both the battery and the alternator to autozone (I don't trust them but they are all I have) and both tested bad. Ended up replacing those as well. Still turned off and threw a code 45. I replaced the 02 sensor and still turned off on me today and code 45 again. I don't have much else to go on other than it still dies after I take it around the block 1 time and the idling sounds a little rough. Foot on the gas it sounds great only when I come off the gas and it goes below 1k rpm does it start wanting to die on me.

Unrelated (I think) the radiator fan runs for a long time after the car turns off. Seems like a common problem. Any advice to tell if it is the relay or the temp sensor? I can replace both I guess if they are inexpensive and easy.

Thanks alot for any advice!

 

[CaptainTurbo]

Hello fellow GN lovers.
I recieved an '87 from my dad and I am having a hard time narrowing down what needs to be fixed. I jave read many posts on this site but still haven't located the root cause. Let me preface this that 1, I am very new to working on my own cars and 2, this car sat fairly stagnant for 2 years.

At first I had to power brake the car in order to get it to my house. While I had my foot on the gas everything was fine. It seemed when it got down below 1k rpm it would die. When I really looked into it, it seemed to do it more when the engine was warm. My dad told me he had this issue and it was the MAF sensor. Changed that. Didn't stop. I also changed the spark plugs and wires because I thought it sounded like a firing issue. Then I noticed the lights dimming when I removed our trickle charger. I took both the battery and the alternator to autozone (I don't trust them but they are all I have) and both tested bad. Ended up replacing those as well. Still turned off and threw a code 45. I replaced the 02 sensor and still turned off on me today and code 45 again. I don't have much else to go on other than it still dies after I take it around the block 1 time and the idling sounds a little rough. Foot on the gas it sounds great only when I come off the gas and it goes below 1k rpm does it start wanting to die on me.

Unrelated (I think) the radiator fan runs for a long time after the car turns off. Seems like a common problem. Any advice to tell if it is the relay or the temp sensor? I can replace both I guess if they are inexpensive and easy.

Thanks alot for any advice!

Hello Jerico. Try cleaning the throttle body along with the idle air control. (it's that kinda square thing with a I think 4 wire connector plugged into it on the front of the throttle body) Be careful with unplugging it as it has very little clearance with the turbo inlet hose. Remove it with a crescent wrench. Feel free to use plenty of carburetor cleaner in the passageway and maybe a small bristle brush that fits in the hole. Clean the throttle body with the carb cleaner also. The idle air control valve may have failed also. They are available from Delco. Your second item on your list is the cooling fan continuing to run after shut down. This is normal. The engineers put a fan delay relay on these cars to cool the engine compartment after shut down. Something about a hot ass turbo right on top of the engine I suppose. Good luck and try not to get to many tickets. Mitchell

 

[TexasT]

The Grand National / T-Type / Turbo Regal Buick Spring Cleaning Guide

Spring Cleaning Guide for Buick Turbo Regals and Grand Nationals

www.gnttype.org

Sounds like a "spring cleaning" is in order. Replacing the vacuum lines might be in order if you cant keep it idling.

 

[pacecarta]

start with looking at the possible reasons for the code you do have

Malfunction Codes Reference

ECM Trouble Codes and Diagnostics for Buick 3.8l SFI Turbo V6

www.gnttype.org

 

[~JM~]

Bookmark this site: Vortex Buicks

 

[dougf]

Something to take a look at.

I'm sure Brad will have more information for you as well.

 

[Jericho]

Hello Jerico. Try cleaning the throttle body along with the idle air control. (it's that kinda square thing with a I think 4 wire connector plugged into it on the front of the throttle body) Be careful with unplugging it as it has very little clearance with the turbo inlet hose. Remove it with a crescent wrench. Feel free to use plenty of carburetor cleaner in the passageway and maybe a small bristle brush that fits in the hole. Clean the throttle body with the carb cleaner also. The idle air control valve may have failed also. They are available from Delco. Your second item on your list is the cooling fan continuing to run after shut down. This is normal. The engineers put a fan delay relay on these cars to cool the engine compartment after shut down. Something about a hot ass turbo right on top of the engine I suppose. Good luck and try not to get to many tickets. Mitchell

Oh Captain my captain,

Finally got a chance to do this. The throttle body was black. Alot of build up and needed a cleaning for sure. Idle sounds better but still think it is struggling. I have 2 cars parked behind the GN so hopefully I get it out around the block tomorrow. It idles at 900 rpm the car sounds like it is oscillating up and down but the rpm doesn't change. It died on idle one time but I am now sitting and rev'ing for about 20 minutes and it stays on. That valve is relatively cheap. Is there a way to test or is it kind of like the other things I have replaced? Jus worth replacing either way?

 

[Jericho]

The Grand National / T-Type / Turbo Regal Buick Spring Cleaning Guide

Spring Cleaning Guide for Buick Turbo Regals and Grand Nationals

www.gnttype.org

Sounds like a "spring cleaning" is in order. Replacing the vacuum lines might be in order if you cant keep it idling.

I thought about doing the vacuum lines but again, I am a novice. The car can idle. It dies when i take it on the road after i let off the gas. Usually when i give it alot of gas and the let off abruptly is when i see it the most. Only when the car is warm. I can't get it to stall off a cold start idle. Sometimes it dies but after the first stall on an idle, it stays on. When it stalls as i drive it, it will happen everytime i completely let off the throttle and I will have to power brake it home.

The spring cleaning seems like alot though I wanted to do the fuel filter and a car buddy of mine just recommended some fuel additive. Oil is easy. Would you recommend i take it to a professional for all that?

 

[Jericho]

start with looking at the possible reasons for the code you do have

Malfunction Codes Reference

ECM Trouble Codes and Diagnostics for Buick 3.8l SFI Turbo V6

www.gnttype.org

I replaced the O2 sensor so based on that article, maybe my fuel injectors? I was thinking those wouldn't be terrible to replace. Since I replaced the sensor the rich condition is real. I just don't kno how to narrow it down.

 

[Jericho]

Bookmark this site: Vortex Buicks

Appreciate it. Seems like a lot of useful info!

 

[Jericho]

Something to take a look at.

I'm sure Brad will have more information for you as well.

I was staying away from that because of the $200+ price tag. Though it kind of sounds like the same issue. However, I think he says as he is in mid throttle the engine dies. I might have to ask him how to diagnose without a logger.