Alrighty fellas, here is one to wrap your brains around... Ive got a '92 RS that came with the 305 that we all know and hate. sadly(happily) It finally died and forced me(allowed me) to replace it. due to budget constraints I couldnt go with a full on LS swap, all though I would have liked to. so I bought one of these:

http://www.jegs.com/p/Chevrolet-Perf...32025/10002/-1

seemed to be the best bang for my buck...

after getting all the appropriate parts, intake manifold, larger throttle body, bigger injectors, bigger fuel pump, 350 knock sensor and ESC module; I went ahead and also got a few "go faster" parts like aluminum pulleys and water pump, 1.6 ratio full roller rockers and MSD distributor and 6AL-2 box.

obviously all of this was going to need a custom Prom made for it to behave so I found a place, Sinister Performance LLC to make the new chip for me.
they have been really helpful and happy to give advice and suggestions as well as instructions as to what they need from YOU to make a new PROM chip.

now here comes the issues, first off, the ECU insists on running like 30* timing advance at idle (I have already gone throught the appropriate procedure for setting the base timing). which brings up another issue, when I have the base timing set to TDC like its supposed to be, the thing runs like a pig, spits sputters and shoots flames out the intake, not exactly desirable. So to get the thing to run decent the Base timing has to be set to around 10* advance, but no matter what, In park, at idle, it runs it forward to 30+* advance. Furthermore, the thing wont idle at less that 1100 RPM. According to the guys at Sinister, they programed a 750 rpm idle speed.

Occasionally the Rpms will drop that low briefly but when they are down there, it misfires like crazy, shaking the whole car. Ive got a feeling that because I have to have the base timing set so advanced it wont allow the engine to run properly at that low of RPMs.


So, any and all Ideas will be appreciated as to what to check into or what you think might be the cause for my symptoms I will try and provide any further information if you have any questions. And again, in summary my issues are these:

High Idle, wont run smoothly at less than 1100 rpms
Very advanced Idle timing, the ECU commands the timing to run 30* at idle
Advanced Base timing, The base timing must be set to around 10* advance for the engine to operate in a useable fashion

sinister performance claims that it isnt their tune that is making the timing be so advanced. I have no way to check this claim so I have to trust that they are correct.


yes its cheesy but here is a link to the facebook album dedicated to the progress. just so yall can see what all has been going on...


https://www.facebook.com/media/set/?...1&l=23a56f2305

 

Did that engine come w/ a balancer & timing tab?

 

yes, the harmonic balancer came with the long block I purchased. the engine came installed with a little tab on the timing cover with a notch on it, which I can only presume to be indicating TDC when the line on the harmonic balancer lines up

 

i would check for a vac leak around the intake or throttle body

 

check... its tight as a drum

plenty of high temp RTV was abused in the making of this film

 

added a link at the bottom of the original post with pictures of the build... so yall can get an idea about things

 

hows the egr valve did it have one just wondering it,i had similar experience and it was a vac leak

 

the new engine doesnt have the facilities for EGR. i.e. no place in the intake manifold for it to go. All of parts for the original system have been removed.

 

Stock L03 idles at approx 24-27 d SA. 30 is not to far out of norm but on the high side..

 

really? hmm ok, where did you find those specs? I mean I imagine the engine I have is similar to the L03 but not identical

 

L03.bin

 

well, I guess thats one issue semi solved... but it still doesnt explain why I have to have the base timing set to around 10* for it to run smoothly

 

The ECU needs to know exactly the base timing you have set physically at distributor. There is a setting in .bin for that. My base timing is 10 deg. So I need to place 10 in constants in .bin tor intial base timing. Doing so all my timing will be as stated in timing tables. While it may help your idle being at 10dSA with EST unplugged it may be throwing off SA at WOT etc.