wheeljo2

I have a 2007 Vert 6psd manual with 45K miles, just recently installed LS hot cam, new timing chain, power bond balancer and ARP balancer bolt along with PCMforless tune. HP in the 450 range I suspect.

Car has been running perfect until this evening I noticed the engine was breaking down at over 50% throttle and RPM over 3500 felt like a fuel delivery or ignition issue and in my opinion the former not the latter as the engine runs perfect at idle and part-throttle cruise through the gears. No check engine light and no DTC codes.

What do you think maybe a weak fuel pump? How can I check for this other than strap a fuel pressure gauge to the windshield and monitor the pressure when the hiccup occurs.

I plan to pull out the plugs as well to inspect, recently installed new NGK TR55s.

irok

reinstall new GM plugs,preferably iridium.ngk have been known to cause electrical issues with alternator on some of these cars.make sure no. 1 spark plug wire is not resting on alternator

Dano523

Pull your cam sensor, and look for wear on the end of it.

Hence if you did not loctite the cam sprocket bolts, they may be backing out, and this is going to cause problems with sensor giving eradicate readings.

Hell, have you data logged in the first place, since this will tell you right where the problem is to begin with, hence timing or fuel problem.

wheeljo2

Yes I used loctite and ARP cam sprocket bolts. Can you pull the cam sensor without pulling the rack and balancer? If not, I will just get is data logged to diagnose if the spark plugs do not correct my issue thanks. Any way to test my fuel pump voltage etc.?

Dano523

Schrader valve on the rail that you can connect an anolag gauge to check for pressure amounts, and if you data log, watch your injector cycle percentage rates to make sure you not maxing them out with the injectors too small.

As for voltage problem, could be the relay in the fuse block, or could be the connector point in the fuse block for the relay, or even on the bottom of the upper fuse block that connects to the lower block.


If you installed a higher output fuel pump (over say that of the OEM LS9 in tank pump) and you used the oem wire from the fuse block back to the pump with either a external pump or added in a BAP to spin the oem pump faster, bank that its your problem, and you have burnt up the OEM wires from the fuse block to the fuel pump.

wheeljo2

Thanks I will check the fuel pump relay and connection points but my fuel system is stock. Also, I plan to replace the fuel filter as I just recently purchased this Corvette and even though it is low miles at 45K could be the original and being 11 years old could be contaminated.

3X2

You will need to drop the left fuel tank to replace the filter. It may only be available with a fuel pump module.

wheeljo2

Good to know just saw that probably hold off on the tank removal and just get it diagnosed with a scanner if needed after inspecting and changing the plugs.

Dano523

Don't forget to give the MAF a good douching with Maf spray cleaner as well.

wheeljo2

Ok back with an update and positive report... I pulled out my NGK platinum TR55's with 500 miles since the cam swap and re-tune and they looked perfect. However, they come gapped at .055" and my stock AC Delco Iridiums 41-110's are .040" so I dropped the gap to .040" on my NGK's and reinstalled them and went for a drive and it ran perfect all night under all conditions. So either I fixed my issue or it is intermittent and did not occur last night. When it did occur the other night I could pretty much repeat it anytime I wanted at the same spot running through the gears are moderate throttle.