1990 Suburban eratic throttle response
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CF Beginner
Joined: Dec 2018
Posts: 1
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1990 Suburban eratic throttle response
Hey all I've searched older posts on this forum and others and I'm still confused. Here's the problem.
Vehicle is an auction bought 1990 GMC suburban 4x4, 5.7, 245000 miles.
When I bought the truck I had about 80 miles to go to get it home. I drove it home with little problem except the exhaust was cut off Midway and louder than I wanted. Also I noticed that at times the throttle felt unresponsive. I would be happily cruising along at 65 mph and all of a sudden I'd drop speed. It felt like the pedal just didn't understand that I was giving it has and wanted to stay going 65. A little pressure on the pedal seemed to bring it back to speed but this happened thought my trip.
I took the truck to the exhaust shop, left it for a week and then started driving it to and from work. Same situation. 20 miles each way to work and once I get about 60 mph the pedal got finicky. Like it just didn't know what I wanted ito of it. BTW cruise seemed to be inoperable.
So on the 3rd or 4th day I noticed that I had an orange "service engine soon" light on the bottom of the speedometer. I plugged an old OBDI 1 reader in and this light flashed a code 12 and then a 22.
Ok, so today while driving to work it really acted up. I started the truck and it revved super high even after warmed up. I didn't think too much of it but the throttle response got considerably worse. In fact I couldn't get the truck to drive over 50 mph the entire 20 miles each way and now I'm just getting home and pretty worried about the drivability of this truck. I work from 4pm to 4am and unfortunately I work all this week so my time is limited to did the problem.
Any ideas? I'm thinking about TPS, ECM relearning. That's all I've got but I don't know how to do any of those things. Any help would be greatly appreciated. I'll be walking up around noon today to try and get something accomplished before work. Please point me in the right direction!
Vehicle is an auction bought 1990 GMC suburban 4x4, 5.7, 245000 miles.
When I bought the truck I had about 80 miles to go to get it home. I drove it home with little problem except the exhaust was cut off Midway and louder than I wanted. Also I noticed that at times the throttle felt unresponsive. I would be happily cruising along at 65 mph and all of a sudden I'd drop speed. It felt like the pedal just didn't understand that I was giving it has and wanted to stay going 65. A little pressure on the pedal seemed to bring it back to speed but this happened thought my trip.
I took the truck to the exhaust shop, left it for a week and then started driving it to and from work. Same situation. 20 miles each way to work and once I get about 60 mph the pedal got finicky. Like it just didn't know what I wanted ito of it. BTW cruise seemed to be inoperable.
So on the 3rd or 4th day I noticed that I had an orange "service engine soon" light on the bottom of the speedometer. I plugged an old OBDI 1 reader in and this light flashed a code 12 and then a 22.
Ok, so today while driving to work it really acted up. I started the truck and it revved super high even after warmed up. I didn't think too much of it but the throttle response got considerably worse. In fact I couldn't get the truck to drive over 50 mph the entire 20 miles each way and now I'm just getting home and pretty worried about the drivability of this truck. I work from 4pm to 4am and unfortunately I work all this week so my time is limited to did the problem.
Any ideas? I'm thinking about TPS, ECM relearning. That's all I've got but I don't know how to do any of those things. Any help would be greatly appreciated. I'll be walking up around noon today to try and get something accomplished before work. Please point me in the right direction!
CF Monarch
Joined: Oct 2017
Posts: 4,605
Likes: 269
From: USA
Hey all I've searched older posts on this forum and others and I'm still confused. Here's the problem.
Vehicle is an auction bought 1990 GMC suburban 4x4, 5.7, 245000 miles.
When I bought the truck I had about 80 miles to go to get it home. I drove it home with little problem except the exhaust was cut off Midway and louder than I wanted. Also I noticed that at times the throttle felt unresponsive. I would be happily cruising along at 65 mph and all of a sudden I'd drop speed. It felt like the pedal just didn't understand that I was giving it has and wanted to stay going 65. A little pressure on the pedal seemed to bring it back to speed but this happened thought my trip.
I took the truck to the exhaust shop, left it for a week and then started driving it to and from work. Same situation. 20 miles each way to work and once I get about 60 mph the pedal got finicky. Like it just didn't know what I wanted ito of it. BTW cruise seemed to be inoperable.
So on the 3rd or 4th day I noticed that I had an orange "service engine soon" light on the bottom of the speedometer. I plugged an old OBDI 1 reader in and this light flashed a code 12 and then a 22.
Ok, so today while driving to work it really acted up. I started the truck and it revved super high even after warmed up. I didn't think too much of it but the throttle response got considerably worse. In fact I couldn't get the truck to drive over 50 mph the entire 20 miles each way and now I'm just getting home and pretty worried about the drivability of this truck. I work from 4pm to 4am and unfortunately I work all this week so my time is limited to did the problem.
Any ideas? I'm thinking about TPS, ECM relearning. That's all I've got but I don't know how to do any of those things. Any help would be greatly appreciated. I'll be walking up around noon today to try and get something accomplished before work. Please point me in the right direction!
Vehicle is an auction bought 1990 GMC suburban 4x4, 5.7, 245000 miles.
When I bought the truck I had about 80 miles to go to get it home. I drove it home with little problem except the exhaust was cut off Midway and louder than I wanted. Also I noticed that at times the throttle felt unresponsive. I would be happily cruising along at 65 mph and all of a sudden I'd drop speed. It felt like the pedal just didn't understand that I was giving it has and wanted to stay going 65. A little pressure on the pedal seemed to bring it back to speed but this happened thought my trip.
I took the truck to the exhaust shop, left it for a week and then started driving it to and from work. Same situation. 20 miles each way to work and once I get about 60 mph the pedal got finicky. Like it just didn't know what I wanted ito of it. BTW cruise seemed to be inoperable.
So on the 3rd or 4th day I noticed that I had an orange "service engine soon" light on the bottom of the speedometer. I plugged an old OBDI 1 reader in and this light flashed a code 12 and then a 22.
Ok, so today while driving to work it really acted up. I started the truck and it revved super high even after warmed up. I didn't think too much of it but the throttle response got considerably worse. In fact I couldn't get the truck to drive over 50 mph the entire 20 miles each way and now I'm just getting home and pretty worried about the drivability of this truck. I work from 4pm to 4am and unfortunately I work all this week so my time is limited to did the problem.
Any ideas? I'm thinking about TPS, ECM relearning. That's all I've got but I don't know how to do any of those things. Any help would be greatly appreciated. I'll be walking up around noon today to try and get something accomplished before work. Please point me in the right direction!
Last edited by oilcanhenry; Dec 28, 2018 at 5:09 AM.
