bad throttle reactions

[dsm'r sk1mp]

Ok, i picked up a 90 plymouth laser turbo. I got it started finnally, and it has a great idle. I pushed in the throttle gently and it went into a throttle surge. Pretty much it sounded exactly like when a DSM has idle surge but it only does this between one thousand and two thousand RPM. If i give it full throttle and get the motor past two grand, it has perfect throttle reaction. As soon as the car goes back down below two grand, it has perfect idle. Compression checks out fine. no vacuum leaks. I want to say throttle position sensor. Can any one else let me know what you think?

 

[Absit]

I think you've got the right idea with the TPS, but you're not remembering the TPS doesn't have anything to do with idle on a 1G, they have an independant Idle Switch, check that.

 

[blaze12]

Having same problem with my car right now , make sure your ecu is a 90 ecu. Did you but the car with these problems or did they just start happening?

 

[dsm'r sk1mp]

I do know that. the reason why I stated that in the post is becuase i dont want people say idle surge. it ACTS like idle surge between one and two grand RPM. but idles at 5 - 8 hundred rpm.

i bought the car not running. thats why im not sure how it performed before i got it. I had the same idea with the ecu, so i asked the guy i bought it from, he was one of those guys that doesnt know how to change oil, so he went to napa and ordered a brand new one ecu to brighten the deal for me. so i know its the exact ecu for this car.

 

[blaze12]

Yeah then I would look into your TPS or ISC

Correct me if Im wrong but i think if the TPS was telling the computer false reading about where the throttle was , it would purge the injectors making your idle surge.

 

[dsm'r sk1mp]

So after SIX months of working on the laser I have figured it out. The cam angle sensor ended up being the problem. So, under future use and information I will tell you the problems and what the solution was for me. The car had perfect idle and compression. Fuel pressure was fine , computer was fine. When pressing the throttle and reaching 1000 to 2000 rpm the car had a "throttle surge". This throttle surge would not let me rev passed 2000 rpm unless I gave it full throttle. After it climbed passed two thousad rpm it had perfect throttle reaction and no miss fire. I had replaced every sensor from the turbo all the way up to the throttle body. Knock sensor and fps. I found an old black top cam angle sensor in one of my extra parts boxes and put that on the car. This had finally solved my problem. I cannot explain why because it makes absolutly no sense to me why that fixed it but it did. Thanks for the help boys. Hope this information helps others

 

[strokin4dr]

Good job figuring it out yourself. This is where dsmlink would have saved hours and hours of hassle. You can just log any sensor to make sure it is working correctly.