I have a 69 camaro with a lt4 in it and seems like it is hitting a rev limiter above 5100 rpm it has a new alternator, new msd coil, newer msd opti, new plugs and wires. here are the specs on the engine

12:1 compression
Eagle h beam Rods
Eagle crank
Srp pistons
Tea stage 3 LT4 heads with port matched LT4 intake
Arp head studs
Arp main studs and rod bolts
comp 987 dual springs
titanium retainers
custom ground cam fro TEA 236/246 610intake
618exhaust 114LSA
30lb injectors
Hardened pushrods
high volume oil pump
MSD opitspark
New GM waterpump
Holley 58MM throttle body
PCM with motor tune in it
total seal rings
4 bolt main
clevite bearings
0 decked
balnced and blue printed

The tuner also said that alternator voltage was reading 14.1 but at the coil it was reading 12.6 then it drops to 11.6 to 11.4 in the upper rpms. He also said that the actual igintion timing that the scan tool is showing does not match the targeted spark in the wideopen spark table.

thanks guys for your help the tuner didnt seem to be much

 

What kind of tranny? Are you running a OBDI or II pcm?

 

turbo 350 and obdII and it has 2002 zo6 maf 02s are tuned out.

 

sounds like a nice setup! Are you going lean at all? how's fuel pressure? mine and my buddys timing both show about + 2 to 3 degrees difference with a scan tool from what the wot table is set at, don't know why.

 

no its runnin a little on the fat side fuel pressure is up around 48 psi i beleave.

 

where is your voltage drop at the coil power feed? if so what about running a heavy wire straight from the battery over to the coil to make sure it has a good feed. What about an ignition box? are you running one? somebody didn't stick a 5k pill in it did they? If you aren't running a box you probably should be.

 

i put a digital 6 on it rev limiter is set up at 6800 rpm and the voltage drop is at the coil. Is it normal to have that much drop at the coil?

thanks for your help

 

I honestly don't know about Voltage drop to coil. Do you still have the coil mounted on the front of the head? It should have a body ground strap going to that stud in the head that the coil assembly mounts to as well. Is it just going flat at 5100 or actually studdering like a mis? Are you sure the opti , cap and rotor are good? also check those plugs for the opti for corrosion, both ends( electrical wires not plug wires). Is the car strong to 5100 like it should be?

 

Try running without the ignition box hooked up to rule it out as well.

 

i put the ignition box on after the problem to try to solve it.. how do you tell if the opti is bad? i pulled it out and it looks fine rotor screws are tight nothing funny looking in there.

 

You really can't test the opti you pretty much have to just try a different one to rule it out. The wiring to them is known to corrode and is very sensitive, make sure its good.

 

the coil is mounted to the head. I dont have a ground strap hooked up to that stud its grounded elsewere but i will put a ground to it for *****. It runs pretty damn strong up to 5100 its making 385 to the wheels at around 5000.

 

any more suggestions on this?

 

up up and away