Ok so heres the thing, my car has been runnin rough for awile now, feels like it is shifting early not sure if it is doing that or something else is makeing it feel like that. Stuttering on take off choppy idle. I have just delt with it, kinda ran out of money you know, the other day all of my gauges stoped working, the speedo stuck on 30 mph, the battery went to 0 and the temp went to 240. But when that happened i was mad but i relized my car was running better, as in no early shift, great idle. Well I figured out that my fuse was blown, I replaced it and the car started running like crap agian. Does any body know why this is ?

I have replaced....
TPS
CAP, roter
plugs, wires
map
o2
fuel pump, filter
knock sensor



I also have my esc unpluged because I was blowing dark black smoke, and I was told that the knock sensor was detecting a knock due to the stroker motor and was retarding the timing thus causing really rich mixture. No more black smoke now

 

I don't see that you checked your VSS (vehicle speed sensor), if you have an electronic speedo a bad vss will effect it, a faulty vss signal going to the ecm can cause many of the symptims you mention. You need to let us know what your driving to get more.

 

Sorry I am driving a 90 Iroc with the stock block punched to a 383 and the siamese runner set up. 700 r4 with shift kit, b&m 2500 torque converter.

 

See my attachment to my post "No tach, no speedo" for some reading for about the vss and how important it is to our cars. Your mods may be pushing the limits of the ECM's ability to compensate for the readings/signals it is getting from all the engine's sensors. You've got an engine system that even controls your transmission. So while your mods are cool, you put the stock settings the computer expects to see out of spec. The ecm will compensate but only to a certain point and then you get codes from SES, if you're lucky, to warn you she's out of spec or if you're not so lucky, you get an unpredicable crappy running car. Not sure how you are running with the Electronic Spark Control disconnected, the ECM has lost control of it's ability to adjust timing so that would definately affect a smooth running engine. Most likely the ECM is defaulting and at times using assumed signals to control the motor and those may not match what the engine needs at times, resulting in rough operation. If you didn't include a prom reprogram following the mods, that maybe the reason for rough running and odd shifting. Recommendation is to find your local street mod shop that can reflash your stock prom and rehook up all the sensors. In doing so, they should also be able to check whether your VSS is working correctly too.

Hope this helps get you started. My son and I just completed a complete wiring harness swap, we verified every circuit, relay, sensor, wire connection and I am now confident the speedo guage on my son's car is shot. I didn't change the harness just for that, the old harness was so bad and hacked into, we couldn't diagnose the car. I also stumbled on a possible bad TPS. Electrical issues suck, but be methodic and work it circuit by circuit, make sure you have the correct sensors for the mods you've made too. Not sure if a stock 350 knock sensor works for a 383. A tuner/dyno shop maybe the only way you're going to figure some of this out.

 

Thanks a bunch I will check into that vss thing, I'm not sure why its running great with the esc unplugged but the difference between plugged and unpluged is night and day, It just seem now that the gauges are not working that it is even running better. But I put the fuse back in and it runs like crap again. Like the gauges tell the computer what to do, Do they ? IDK this car is driving me nuts but I don't have the heart to sell it. And don't have the money that I need to get the car to be tip top agian, I will just continue with the trial and error.

 

The guages do not send signals to the ECM they only recieve them and provide you with basic information as to how the car is running. The instrument cluster is still part of the circuits that run back and forth to the ECM and you may have a bad ground or short in the cluster which may explain both problems of why its not working and why the car runs poorly when you plug the cluster's fuse back in. You can actually remove the cluster, plug the fuse back in and the car will start. I'd be curious to see if it runs like crap under that situation. If it doesn't, then you've found the problem is a shorted out cluster. If it still does, then start checking for back grounds. Also a disconnected wire or connector under the dash can have unpredicable results.

 

OK thanks well I don know my tach has not worked since I have had the car I just figured it was because of the MSD ignition box that the PO put in it, cause the tach lead on the dis is just cut off

 

Holy cow, no wonder it runs like crap when you plug the ESC in, it's not getting the required signals from your distributor anymore, a vital link to running the car correctly under computer control.

 

Can I pick your guys brain? We are swapping 305 tbi to a 375 hp carbed 350, auto. we are keeping the 700r4 and would like to use the stock gauges tach, speedo etc. Can we use this distributor and coil or is the timing controled by the ecm? Will not having all the sensors hooked up give bad readings to the ecm and make it not run right? What about the tranny lockup will it work? Hmm i didnt see a vaccuum port on the distributor this must mean ecm comtrols advance, Maybe I answered one of my questions but clarification would be great, thanks

 

It runs like crap with the esc pluged in and runs good with it unpluged I know that sounds backwards

 

You're going to have a tough time of it, keeping the stock distributor that is. You're correct there is no vaccum advance. The ECM will control it with the ESC if your car has one. We don't know what you're driving. The computer will also control the tranny with signals from the brake switch, the TCC, the VSS and various other sensors you need to keep on the new engine in order to get it working correctly.