Thanks for everyone's input! :icon_biggrin: Just to answer your questions, I did line timing gears up dot-to-dot. Took pushrods out and put them in cardboard I made to keep them in order.  I checked wires and they are right, however they may not be on the exact tower on the coils.  Changed plug gap to 28. However did use aftermarket coils and IM. but that was done 6 months ago and car seemed to run great up till the time the came failed. Upon initially completing the upgrades mentioned, I did not change the rocker studs and just bottomed out the nuts to spec as if it still had the 1:5 rockers. Someone suggested as you did that maybe the valves weren't closing all the way. Just put in the studs and adjusted valves starting at zero lash plus 1 1/2 turns. Still doing the same thing. Car ran pretty good before the teardown and upgrade, just a slight miss on #5. Very frustrated and have run out of Satudays and patience to work on it. Will hook up a scan tool and try to read the data and see what the computer/sensors are doing. Thanks again yall!!!

Help anyone. I did all of the recommended mods to my engine while I had to replace the camshaft for worn lobes.  Put in an H260 comp cams cam, 1:6 steel rockers, LS1 valve springs, locks and shims, older style rocker studs and manually adjusted valves, new timing chain and 22# fuel injectors. Car runs like crap.  :icon_evil:Will idle smooth but anything above idle on acceleration and it makes a pop-pop-pop-pop noise like it is backfiring through the intake or out the exhaust. Spits and sputters horribly. I am out of options. :damnit1: Have not had the chip done yet because others have said you would be able to drive it and it run pretty smooth without changing the chip.  I do not want to spend money for a chip if there is something else wrong. It seems as if it is spark knocking badly and the retarding the timing. To be quite honest, I am fed up with this car and see no good reason to not crush it! If nothing else for the joy of knowing my troubles are over. If any one has any suggestions as to what may be wrong, please let me know. I have spent over 3,000 dollars in parts trying to make this car run and it seems to be all for nought. Please help!!

You have been very helpful both on the phone and the forums. Thanks, I greatly appreciate it! :icon_biggrin:

Thanks, man! ;)

Are my posts going to the forums? Usually I get a response but on my last few posts I have gotten nothing back. Hope I wasn't blackballed! :icon_confused: If someone will respond to this post I will feel better. :icon_wink:

ANYBODY HAVE ANY OF THE 82 MODEL 2.8 LITER STUDS AND NUTS? tHE GM DEALER IS RIDICULOUS!! :icon_evil:

Thanks, will definitely check into it if I can get it running right and dont torch it first!

Checked the plugs and wires.They are in the right order and good. I am thinking valve issue also. When I was installing the valvesprings, the cylinders held pressure as I used compressed air to remove the valve keepers without removing the heads. However with the cam and the 1:6 rockers, maybe the valves are'nt closing all the way under load.  I wonder if the valves can be manually adjusted using the current rocker studs and if it is even required to manually adjust them. Most people on the forums seem to have installed them and it was a turnkey modification. Thanks for your input. :twitch:

Hey All! Just recently got the upgrades done to the TGP.  I put in a Comp Cams H260 cam, new lifters, timing chain and gears. Also put in 1:6 steel rockers, LS1 valve springs, and 22# injectors. Also put in a 180 degree thermostat. However, car runs horrible. It ran better with a skip on #5 cylinder and the cam lobes worn down. :damnit1: Have not had a chip made for it yet as I am not sure if there is a mechanical problem. Car seems to idle slightly rougher than before but actually sounds pretty good with a little more thump coming from the cam. When you accelerate from a stop the car seems to have half the power it had before and when you floor it it starts bucking and it sounds like it is backfiring through the turbo. Rapid bucking and misfiring and no power! :icon_evil: Is it possible that with the 1:6 rockers that new rocker studs are needed to enable valve adjustment or do you just torque the valves down till they bottom out as before? I have read posts on this before and all seem to say you torque the rocker arms down as if they were the original 1:5's. If it doesnt matter which rocker arm you have in terms of rocker torque/adjustment, if you change the cam to a bigger cam, would this require manual valve adjustment?  Also, car shows check fuel on the DIC. Checked fuel pressure and it was good. Please help as I am ready to set it on fire and be done with it!

Inside the showroom. Dealer was a family friend and was ecstatic to get one. Had 3000 miles on it when we got it but it was actually was a factory show car when he got it. Still have the original paperwork in
dash where it was shipped to different facilities.

$23,500 in 1989! :icon_biggrin:

Dropped the engine out of the body with the trans annd cradle attached. Removed the camshaft and sure enough #10 lobe was half the height of the other exhaust lobes. Problem found. Installed new H260 cam, LS1 springs, shims and retainers, lifters and am installing the 1:6 rockers. Is it required to modify the guideplates? Some say yes and some here say no. Also installed the 23# injectors into my rail. Hope she runs good when I get it back in! :icon_biggrin:

Northstar!!!!!!

What a bunch of idiots! :gr_mad: Pathetic!! A good a.. kicking may resolve their problem! :icon_cool:

I feel your pain about everytime you turn around these cars need something. My wife can't understand (and just being honest i can't either) why we feel compelled to keep these things together! :icon_confused:  Must be the challenge, because I can't help it! It think it must be the exhilaration we get when they actually run like they are capable of or in some cases when we remember back to days when they ran like they should. To quote a line from the bug that went to the light in A Bug's Life, "I just can't help it, it's so beautiful!!" Keep the faith. I keep telling my wife this everytime I discuss my plans on how to upgrade or fix another problem. All of the guys on this forum are great!! ;)