i just did a CFI to TPI swap. but i dont have a VSS. what are the symtoms of not having one hooked up. if i hit 70mph the check engine light comes on. and if i sit at an idle the check engine light comes on. and i dont have a code checker . thanks

and also in the morning when i first start it up and start to drive it, the engine will not go above 2000 rpms. it acts like a rev limiter. but as soon as i drive for 10 mins it runs just fine(other then the comp throwing codes) any help would be appreiciated(sp?) thanks

 

yo Red...

Why Not just do the Paperclip thing to read your codes..

the VSS controls TCC lockup among other things.. That could explain your Code at 70 mph...

as Far as the 2000 RPM thing, what year TPI did you swap in again ? MAF or SD ?

 

its an 88 MAF

and how do you do that paper clip thing?

 

-THE PAPER CLIP THING-

1.) start with car OFF!

2.) bend a paper clip so you can use it as a jumper on the A and B terminals on your ALDL connector (these are two terminals on the little connector just under your driver side dash, their in the top row, all the way to the right).

3.) turn the ignition to run, DON'T START IT THOUGH!

4.) count the flashes. it should flash code 12 ( 1 flash, pause, 2 flashes) three times first, this means its diagnostic system is working, and then it will flash any stored trouble codes. don't worry if you don't get them the first time, it will keep cycling through its codes until you stop it by turning off the ignition.

5.) check what the codes mean. the FAQ section on this site will give you a general idea, but it won't be specific to your vehical; some codes mean different things for different cars. if you don't have access to a service manual for your car, which will tell you what the codes mean and how to troubleshoot them, put another post on this site and sombody can check for you that has one.

Happy Hunting

 

On my IROC the ALDL is at the front bottom of the dash to right of the steering wheel. It may have a plastic cover that must be removed to reveal the connector pins.

Insert the ends of the paper clip into ALDL pins A&B (upper right) and turn On the ignition.

Then count the SES flashes. They will start with three "12s", followed by each stored code flashed three times, ending with three "12s" to signal the end of the codes.

 

thanks

 

red, i read once on here somewhere that driving without the VSS could cause computer problems. not sure how true this is but try to get it fixed as asap. why cant you hook it up now?

 

right now i dont have a VSS installed(dont beleive CFI cars had them) so when i get some more money ill buy one and install it.

thanks for all the help

 

 

what

 

If your car was originally controlled by a computer (like a CCC or the CFI setup) it should have a VSS. I believe you can use the original VSS, but you'll have to check a wiring diagram of the VSS harness and see what needs to be connected to the TPI harness.

My '85 Monte SS originally had a CCC-system, and I swapped to an '87 TPI MAF setup. Wired in my original VSS, and all is well. Still cooking two years later!

 

Look under the dash where the speedo is. There should be a little green box with wires going to the back of the speedo and some other wires going somewhere else. That is the optical VSS.
Your car will run OK without it, but it will never run really good.
J