'98 Corvette A4 questions and concerns, any answers appreciated
08-08-2013, 06:02 PM
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'98 Corvette A4 questions and concerns, any answers appreciated I just bought a 98 Corvette Automatic. The car has a cam and full exhaust and is tuned speed density. It has 99k miles on it and I have a few questions about the way its shifting.
During normal driving, the car shifts hard from 1st to 2nd, sometimes its a firm hard shift, sometimes if I don't have the gas depressed much its more of a clunk hard shift. Also during normal driving when it shifts into over drive it's more like it slides into over drive. I say slides because it doesn't feel like it sleeps when I push the gas down during the shift into OD, the rpms dont rev like its slipping, they grab and the car pulls.
During WOT driving the car shifts from first to 2nd hard, it will chirp into 2nd, but shifting from 2nd to 3rd it will not shift it will just bang off the rev limiter.
I havent done a whole lot of experimenting due to the fact that I dont want to destroy the transmission completely. Both times I have done WOT runs it has chirped 2nd and wont shift to 3rd.
I don't have the notorius 1870 code but I do have some TCS codes that dont trigger a CEL but are there if you read codes through the information center. I haven't take the car to the shop to check fluid levels or flush the trans yet because I want to gather other information on what to check so I can get everything knocked out at once.
On the information center 'gauges' the trans fluid never has exceeded 221* during all the times I have actually watched it.
Any help is greatly appreciated.
During normal driving, the car shifts hard from 1st to 2nd, sometimes its a firm hard shift, sometimes if I don't have the gas depressed much its more of a clunk hard shift. Also during normal driving when it shifts into over drive it's more like it slides into over drive. I say slides because it doesn't feel like it sleeps when I push the gas down during the shift into OD, the rpms dont rev like its slipping, they grab and the car pulls.
During WOT driving the car shifts from first to 2nd hard, it will chirp into 2nd, but shifting from 2nd to 3rd it will not shift it will just bang off the rev limiter.
I havent done a whole lot of experimenting due to the fact that I dont want to destroy the transmission completely. Both times I have done WOT runs it has chirped 2nd and wont shift to 3rd.
I don't have the notorius 1870 code but I do have some TCS codes that dont trigger a CEL but are there if you read codes through the information center. I haven't take the car to the shop to check fluid levels or flush the trans yet because I want to gather other information on what to check so I can get everything knocked out at once.
On the information center 'gauges' the trans fluid never has exceeded 221* during all the times I have actually watched it.
Any help is greatly appreciated.
08-09-2013, 01:07 AM
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Missing a 2/3 shift is common for 2 reasons, 1. the 3/4 clutch pack is on the way out, or 2. its a slow shift (naturally) and it isn't tuned properly. In all respects with an electronic transmission you need to know what it is being asked to do then compare it to what it is actually doing. You need tuning software to see this real time. Also, depending on how you "fail" your MAF signal to make/force the PCM enter SD mode, it can effect your shifts also.
