I have a 87 Z28 with a 350 TPI. I just put this engine in, replacing another 350. This car is very new to me. Here is my question:

At first my problem wasnt really a big deal.....very occasionaly when I would start the engine, she would jump from 750 idle rpm to 1000. When she got warm all was good.
Now though, she ALWAYS RUNS ROUGH ( in drive or park) and jumps from 750 to 1000 warm or cold. This rpm jump happens only when in nuetral or park not in drive.
She started doing this today after a little time at wide open Throttle.


HeLp PlEaSe I am going crazy with worry over here


Dennis

 

Are you saying the idle jumps back and forth while it is in park/neutral or that it will go from 750 to 1000 when you take it out of gear. Is your check engine light coming on, if so, what are the codes?

 

The idle jumps back and forth while in park or nuetral. It doesnt matter if the motor is warm or cold.
While it is in drive, the rpms don't jump (it stays at 750) but the engine runs noticabley more rough.
No check engine light

Regards
Dennis

 

vaccum leak?

 

Did you remember to adjust the TV cable after you hooked it back up to the throttle body?

 

I checked all the vacuum hoses and plugs and they seemed to be fine.
As to the tv cable...... whats that? And how do I adjust it?


Dennis

 

The TV cable controls the line pressure, shift points, shift feel, part throttle downshifts, and detent downshifts.

 

This is how it is adjusted.

 

Trickster,
Thanks so much, I bet thats what it is. My shifts have been extra hard too so this sounds right. Ill check it in the morning. Ill let you know what happens of it. Can I ask you for a favour though? Could you send me the pic with numbers 832 and up? the directions mention these numbers mostly:hail:

Thanks again

Dennis

 

Sure can:lala: :lala:

 

I think I have a different tranny or something? Because my Haynes manual tells me to do something entirely else to adjust that cable. It tells me to push the cable all the way towards the throttle lever. Your diagrams tell me something else, right?
Either way, my idling prob is fixxed but now I have a new prob. I am experiencing "delayed shifts".
In normal driving circumstances what rpms should I be shifting at? I am shifting at around 3500 to 4000 rpms. And she wont downshift at a cruise unless even when I release the pedal.

any ideas? I am also going to put up a post in the tranny forum, just in case.

Dennis

 

Hello Dennis,

The information that I have posted here for you is straight out of the GM service manual for an 1989 camaro and the procedure for it is the same on your car. You mentioned delayed shifts, this can be caused by the TV cable. I don't know the precise RPM at which the shifts occur because it varies. I am including a shift speed chart in this post. BTW, when was the last time you changed the filter and fluid in your transmission?

 

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Shift speed chart