Well I got the check engine light out, I plugged the vac solenoid in and the light is off..I ran the car down the road tonight w the scan tool hooked up and it was retarding the timing up to 7 deg. So I'm gonna get the lt4 knock module and get some actual exhaust hookd up and see what she does. I also learned tht the car has the awesome 2.73 gears and I'm used to an m6 w 4.10's.

 

I have a new LT4 km for sale $45 shipped in lower 48 states if you're interested let me know aero.coupe@hotmail.com

 

I wish I had a $1 for every one that eventually found they had crossed plug wires. I highly advise you check them 2 or 3 more times.

ignition wiring

You say you ran it down the road and saw KR. But you are complaining about a bad shake at idle. Don't see how KR going down the road could cause a bad idle. But crossed wires could do both.

I don't see why you have to throw parts and money at a problem BEFORE you do testing. Is it easier for you find a module than it is racing fuel?

One other thing. If the programmer supposedly removed the EGR but obviously hasn't. What else did he screw up? Or is it a misunderstanding?

 

wish i woulda known a little sooner man, i ordered one the other night from summit for $65..thanks anyways

 

i dont see it as throwing parts on a vehicle..its pretty much a necessity for an lt1 with a hot cam kit anyways, so i look at it as an upgrade or a need down the road

 

For testing purposes only(You need to find to true cause of knock) a .25 watt/4K resistor(radio shack,less than a dollar) will allow you to bypass the knock sensor. When I put the rr's on my car before it was tuned it was pulling max timing out at wot before I tried the resistor trick, but , my car idled fine and wot felt life I was pulling a bus. The last time I crossed the wires it ran just like you are describing. Check the wires one more time. LF

 

i guess ill check the wires one more time. if that isnt the case, then i will wait for the lt4 knock module to get here and try that along with some actual exhaust. also, when under heavy acceleration, and you let off the throttle, the car will backfire every now and again

 

I don't think the LT4 knock module is going to solve your problem. I do think you need it running roller rockers, but I don't think that is your core problem.

That cam should run "okay" on the stock tune. I don't know if the problem is the new tune or not, but at this point to eliminate some variables, I would put the tune back to stock and see if you still have the problem. If so, then you need to look for vacuum leaks, timing issues, plug issues, or goofed up rocker adjustments.

 

Has anyone checked for a possible fuel issue? I am having a weird injector problem on my 99 that is making my car bog down and idle funny. Check the ohm reading on your injectors and see if one died, running higher lift and different tuning will increase the duty cycle on those little injectors and they will fail quickly if you're pushing over 85% duty.

 

Try this, let different eyes check that the wires are correctly connected. Sometimes we (me included) can continue to look right at a problem and not see it. Have someone else verify that all the plug wires are correctly installed.

Best advice is to have the diagram of how they should be connected to the OPTI right in front of him/her when they're checked. Then have H/H run H/H hands all along the plug wire from where it's connected at the OPTI all the way to where it connects to the spark plug. Sometimes a wire(s) will cross over or twist around other wires causing H/H to lose the routing. That can lead to thinking the wire is correcting routed when, in fact, it isn't.

Each individual plug wire should be physically checked that way; one wire at a time. It's not too hard to mis-route a plug wire due to the way the Opti is mounted and the way the wires are routed.

I've mis-routed two wires too, even when I JUST KNEW I'd routed them correctly. When starting the engine and it back-fired I learned the truth.

If, after doing that, and you continue to have the same problem, I'd next suspect at least one exhaust lifter's preload is set too tightly. If that's the case, the exhaust valve won't fully seat and cause a rough idle and back-firing through the exhaust.

Seems like something simple; just a matter of finding the cause.

Hope this helps.

Jake

West Point ROCKS! Nation's TOP COLLEGE per Forbes Magazine!! Graduation Day Parade 20 May 2010!!!

 

i checked my wires today and had a friend of mine check them as well, all are going to their desired location..i re-read the valve adjustment procedure on shoebox's site again, and noticed that with engine running it is only 1/4 turn preload...i did a 1/2 turn...would that do it or is an extra 1/4 turn not gonna cause a tight valve adjustment? i think im gonna re-run my adjustment today and try 1/4 turn instead

 

You can make as much as one full turn of lifter preload without any problem. In fact, that's probably what your Factory Service Manual calls for; my 96 FSM does.

Since you're now SURE your wires are routed correctly, next step is your lifter preload adjustment since you still seem unsure about the settings being correct. If you're doing it with the engine idling, tell us precisely how you're going about it.

Jake

West Point ROCKS! Nation's TOP COLLEGE per Forbes Magazine!! Graduation Day Parade 20 May 2010!!!

 

i let the engine warm up to temp, then at idle, i loosened the poly lock with my allen head while holding the nut with a wrench, loosen the allen screw out all the way, loosen the nut til i could hear audible clicking...left it click for 3 or 4 clicks to make sure lifters were pumped up, tightened the nut till the clicking was gone, then an additional 1/2 turn..holding the nut with my wrench, i tightend the poly lock down w/ my allen key..i started on left bank going down the row then the same on the right bank...

 

well, i have been messing with this car off and on over the winter hear but we got hit with a blizzard over January..anyways car still isnt running right..got exhaust on it,plug wires are confirmed to their correct positions, put new intake gaskets on and totally resealed the intake(EGR block offs, TB, etc.) adjusted the RR's. does anyone think that a non-tuned pcm would cause this situation with a Hot cam kit, slightly thinner headgasket and shorty headers with egr delete? i basically just look at the car and say...FML

 

Have you put a stock programmed PCM back in it? In your first post you stated it had been reprogrammed.

Is it still shaking bad at idle? If so, something is still very wrong. As I stated before, a stock PCM will run "okay" with no idle issues or rough running issues with a LT4 hotcam. True that I have a CC503 instead of the LT4 hotcam, but the cams are very close in specs.

I have two PCM's and the LT1 Jet programming software for my 1996 Z28. I have one of them setup with PCMforless's CC503 program and the other one is stock(except I did program it for 30# injectors instead of 24#.....fuel, spark, MAF tables are stock on this one.). My CC503 idles just fine with the "stock" PCM.

What kind of vacuum reading do you have at idle?