I've been trying to figure this problem out for months and months now. My engine doesn't give off any check engine lights anymore (finally got that resolved). Basically what happens is when I do anymore than 1/2 throttle, the engine completely misses...it almost sounds like it's hitting a rev limiter. There's NO power at around 3,00 RPM. Heck...I can't even spin the tires anymore...and I could easier before the cam/header swap.

Here's the parts I've replaced:

-Ignition Module
-Ignition Coil
-EST
-Coolant Temp Sensor
-Disabled Knock Sensor with 3.5k bypass resistor
-Spark plug wires/plugs
-Fuel Pump (255)
-Fuel Filter
-Removed Cat

I've probably replaced some other things but I can't think of anything as of right now. I put in a custom chip from Harris Performance to help with the new cam/header swap.

Timing is about 10-12 degrees.

NO CLUE ON WHAT IT COULD BE?!?!?

 

Does the timing advance when you rev it?
Whats the fuel pressure? Is it adjustable?

 

When I rev it, the timing advances...hard to tell how much. I would guess high 20's or so. I also have the fuel pressure set to 48 psi right now. I converted the fuel pressure regulator so you can adjust it. I've tried a bunch of ranges for fuel pressure. As low as 42 PSI all the way up to 54 psi. No Luck.

 

I will just throw this out there for you to ponder on. Could it possibly be weak valve springs.

 

That's another thing I did replace haha I bought some little more heavy duty ones because of the mild cam.

http://www.summitracing.com/parts/SUM-174000/

I've went through the timing about a half dozen times so I think valve floating is out of the question.

Thanks for the suggestion though.

 

I'm starting to think I didn't install the cam in correctly. I thought I lined everything up just fine. Could not breaking it in long enough cause some of the lobes to go flat and cause this issue?

I just ordered a ALDL usb connector so I can diagnose it a little better with my laptop.

 

The newer cams do not require the 30min at or above 1500rpm's I put one in a while ago and I really can't remember what the break in period was if there was one. I am sure this forum has the answer. Maybe your a tooth off but I wouldn't bet on that. Nice looking car!

 

I'm assuming it's something electronic I'm sure. The scanner should help tell me a lot.

 

Well let us know what you find out.

 

If you have a "custom" chip your timing should be set to stock. 6*
I would put your stock chip in and see if that changes anything.

Did the problem just start or has it been this way 4 awhile?

What heads are they? sparkplug brand and gap? Is the MAF good or could it have gone bad? Whats your fuel PSI??

 

I have the stock LB9 heads...I believe I have AC Delco spark plugs gapped at .45. The MAF seems to be fine. The engine code doesnt come up and the engine runs like crap if I unplug it.

I'll try putting in the stock chip and seeing if that does anything. It's always been acting like this since I installed the new cam.

Here's a screenshot of some data from WinALDL. Sorry I dont have more info but I dont really know how to use it well.

 

I ordered a new cam and timing chain. I think the cam I installed wasn't the right one. The duration was 230 i believe and a 110 LSA.

The new one (Lunati 60101) Has lower duration 213/219 with 112 LSA. I also got a single chain timing chain. The first one I installed was a double and I believe it meant for a roller cam engine (87+)

Think this will fix the issue?

 

I was runin a way bigger cam than that. I think mine was .292 or .244@ .50 My cam was so big It idle was at 1000 rpms. and ran so rich it hurt your eyes if you stood near it it. but it was carberated.

What happens if you turn the distributor while its running?

OH, i just read your description again. YOUR RUNNING FI- ok, You do have to check the cam specs. FI- will only run up to a .238(or something like that) I went threw this with summit racing. I ended up removing my FI and running carb because my cam was tooo big for the FI.

Did you double check by bringing it up to number 1 cylinder and checking the lifters to see if its in the correct position?

Call Summit tech line and check the specs on the cam. It doesnt sound like the cam you have is too radical but Sumit Tech told me these only so big you can go with FI.

If its running ok at idle then sounds like timing isssue.