tltd6spd

O.k. I have a 93 speed density lt1 and i rebuilt the motor and installed a lt4 hotcam, 1.6 rockers,and hooker L/T'S. My problem is I can't get the car to run right it will start but then it just surges between 1 and 2k rpm and is running real rich can you guys give me any ideas please anyone, thanks

The Big Show

iTrader: (2)

Any tuning on the new combo or you still running stock tune? Did you replace the opti or you still using original? Still using stock 93 year model injectors?

Need more details...

Angry'Z

yep, more details please <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />

tltd6spd

I'm sorry guys I am using stock 93 injectors, and the original opti on the car, has new plugs and msd 8.5 wires nothing else has changed except I got rid of the airconditioning but that is it besides the cam, rockers and headers. I was thinking maybe my throttle position sensor had gone bad would that cause it to do that, i don't know.Also the pcm has a hypertech chip but that's it I was told that the stock pcm would run the hotcam and other mods i have just fine.

<small>[ November 24, 2002, 01:35 PM: Message edited by: tltd6spd ]</small>

Angry'Z

Sounds a bit computerish to me - I would first remove the chip and try it again. If that doesn't work - try disconnecting the battery for about 10 minutes to get it to drop all the codes that may have been set and try it again. If you believe it's the throttle pos. sensor, after connecting the battery back up, turn the key on and push the throttle all the way down and release (doesn't sound like that's the problem). Sounds like the computer is having a hard time figuring out the right fuel ratio with the new cam and rocker arms. Those new rockers actually make quite a bit of difference. If you can afford it, a custom tune would really be the answer. Let us know what happens. Anyone please jump in if they think I've put him on the wrong track.

Michael

Angry'Z

you did reconnect the MAF --- right? <img border="0" title="" alt="[Razz]" src="gr_tounge.gif" />

Stefan D.

Chances are you need too due one of two things. If you have access to raise the idle do so. If you are running a stock computer program it will need to idle around 850 . Sometimes when the computer is trying to compensate for changes it will dump fuel at the motor on idle. How is the driveability? Next, when the car surges try leaning out the fuel pressure to around 40 psi and see if it changes. Just remeber this will only be a temporary fix because the computer needs to be calibrated. Speed density can only compensate itself about 5 percent if any. The cam and rocker change you made is more than that. My car runs the stock computer w/ a calibrated chip and works fine. Let me know how it goes.

Stefan D.
TY TECH RACING
9.53 139 w/ 1.28 60ft on 175 NOS <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

chevyguy3

iTrader: (4)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Angry'Z:
<strong>you did reconnect the MAF --- right? <img border="0" title="" alt="[Razz]" src="gr_tounge.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">no MAF on 93

sounds like a tuning issue to me. first thing i would do is yank the Hypercrap tuning out, 2nd i would get the car professionally tuned

92 B4C 396 LT-1

Check to see that you installed the drive pin for the opti correctly. It will POSITIVELY go together with the index "tooth" out of position. Your timing would be way off resulting in lazy throttle response and unburned fuel. A scanner will show the timing the computer is attempting to set which won't help you, but a timing light will show what is actually happening. Just find TDC, mark it with chalk and a temporary pointer, and check to see that you are firing 10* or so before TDC.

tltd6spd

Thanks for all the suggestions guys, first i just rebuilt my motor and changed the cam and stuff so i can't really tell how the drivability is because i can't get it to run right to even drive it. Question how do you tell by looking at the drive pin on the opti as to where it is supposed to gok i didn't notice anything out of the ordinary but this is the first lt1 i've ever been inside as well.I threw a code of 36 which has something to do with the vaccum and map sensor would it cause it to load up real bad like it's doing because when it is idleing and i try to give it gas it chokes itself all the way down and dies.

92 B4C 396 LT-1

The drive pin is splined. It has a missing spline area that is intended to match up in a notch in the splined receptacle in the back of the opti, however it will install out of time/phase. Install the pin into the cam gear and rotate the engine until the notch is at 12 o-clock. Orient the notch in the opti to 12 o-clock and carefully slip it over the pin. You can verify whether this is your problem with the timing light before you pull the water pump, damper, and opti.

tltd6spd

thanks for all the help guys i really appreciate all the advise will let you know how it turns out