New here, have a question - ZR-1 Net Registry Forums

93ZR-1 · 06-17-2020

Hello everyone, I just became a member here and wanted to say Hi and possibly pick your brains on an issue that has me stumped.

If you are already on the corvette forums this may sound familiar... and sorry this has turned into a book but I thought all the information would be pertinent.

I have a 1993 ZR-1 with 80,000mi. The car sticks at wide open throttle. Not specific to a gear or the high or normal power setting. It was intermittent at first but now is happening more often. I took off the intake today and cleaned the throttle bodies and butterfly valves, they were seriously dirty and I suspected this was the culprit however after getting it all back together it is still happening. I have checked and lubed the throttle cable, checked the gas pedal and neither seem to be sticking.

Take two; I checked out the connection and surrounding wiring to the TPS and everything looks good, no rough or high or low idle when the car is running. Took it for a drive today and the same thing happened only worse. It was driving normally until I depressed the gas pedal past halfway and the car got stuck at an open throttle position to the point I could not get it out. I had to shift to neutral after slowing down with the brakes and shut the car off. I drove it home gently with light throttle and it drove normally. When it did get stuck, even when I went to neutral it did not run up to redline, it was stuck at around 5000 rpm. Any ideas? Think I might have not gotten all the junk out when I cleaned the throttle bodies and maybe loosened up something that got stuck afterword?

Take three; I took everything apart again. Used an entire can of intake cleaner, and lubed the crap out of all the throttle linkage parts, springs, and cables. Checked the ASR cables and movement, found a rotten vacuum hose and replaced that. Replaced both fresh air hoses because they were worn and cracked.

Took it out for a test drive and it drove wonderfully. Better than it ever has before. Smooth crisp and instant throttle response and return, no hint of hanging up anywhere through the rpm range or the throttle range. The car drove like I imagine it did when it was new.

The latest... so I drove the car again today, everything is normal in the low power setting, however when I set it to high power and floored it, it stuck again between 4500-5000 rpm, a quick kick of the gas pedal got it out and it was more controllable this time but something still isn't right. Any ideas where to go from here?

06-17-2020	#1
93ZR-1 Join Date: Jun 2020 Location: Colorado Posts: 4	New here, have a question Hello everyone, I just became a member here and wanted to say Hi and possibly pick your brains on an issue that has me stumped. If you are already on the corvette forums this may sound familiar... and sorry this has turned into a book but I thought all the information would be pertinent. I have a 1993 ZR-1 with 80,000mi. The car sticks at wide open throttle. Not specific to a gear or the high or normal power setting. It was intermittent at first but now is happening more often. I took off the intake today and cleaned the throttle bodies and butterfly valves, they were seriously dirty and I suspected this was the culprit however after getting it all back together it is still happening. I have checked and lubed the throttle cable, checked the gas pedal and neither seem to be sticking. Take two; I checked out the connection and surrounding wiring to the TPS and everything looks good, no rough or high or low idle when the car is running. Took it for a drive today and the same thing happened only worse. It was driving normally until I depressed the gas pedal past halfway and the car got stuck at an open throttle position to the point I could not get it out. I had to shift to neutral after slowing down with the brakes and shut the car off. I drove it home gently with light throttle and it drove normally. When it did get stuck, even when I went to neutral it did not run up to redline, it was stuck at around 5000 rpm. Any ideas? Think I might have not gotten all the junk out when I cleaned the throttle bodies and maybe loosened up something that got stuck afterword? Take three; I took everything apart again. Used an entire can of intake cleaner, and lubed the crap out of all the throttle linkage parts, springs, and cables. Checked the ASR cables and movement, found a rotten vacuum hose and replaced that. Replaced both fresh air hoses because they were worn and cracked. Took it out for a test drive and it drove wonderfully. Better than it ever has before. Smooth crisp and instant throttle response and return, no hint of hanging up anywhere through the rpm range or the throttle range. The car drove like I imagine it did when it was new. The latest... so I drove the car again today, everything is normal in the low power setting, however when I set it to high power and floored it, it stuck again between 4500-5000 rpm, a quick kick of the gas pedal got it out and it was more controllable this time but something still isn't right. Any ideas where to go from here?