Injuneer

The MSD Opti is know for many faults. MSD can rebuild it for you. But last month I helped a guy on another site track down the cause of the weird surges in engine RPM at idle. We were able to track it down to an erratic pulse signal from the optical cam position sensor in his MSD Opti. Interestingly, he had just had the Opti rebuilt by MSD and reinstalled it on his engine, after which the crazy idle surges started. He junked the MSD and bought a new AC Delco - problem solved.

Dynaspark Opti used to be the best. But the company changed hands several years ago and they started having major problems, with units being defective right out of the box. Check posts by "popo8" (owner of LTXTech.com).... he had the out of the box failure problems, and defended Dynaspark because they willingly sent him replacements without even waiting for him to send the old one back. In the end, he realized the Dynaspark was not the way to go any more, and he now recommends AC Delco.

To run the Bailey Engineering LTCC, you need an Opti with a healthy cam position sensor. It feeds the LTCC "black box", which drives the 8 coils, You need to buy the coils and other parts. He tells you what you need to buy on the website:

Bailey LTCC setup

I have a system that functions just like the LTCC, but uses different hardware. Here is my coil mounting setup:

anmar A

that is an awesome setup injuneer.
so i had the new AC delco opti installed and the car runs flawlessly now. lets hope it will stay that way until next year when i will do the LTCC conversion. now i can start collecting data from my data log and take a look at my fuel injectors and fuel pressure just to make sure i am not running lean. any advice on what to look for?

Injuneer

You can check the fuel pressure first.... tape the gauge to the windshield, take the car out on the road, and take it up to max load - WOT, over 5,000 RPM. The fuel pressure should never drop below 40psi.

If you are OK there, chances are the fuel system can supply the required fuel. Next step would be to look at the O2 sensor readings at WOT/5,000+ RPM. While the stock narrow-band sensors aren't very accurate at the 12.8 - 13.2:1 that usually produces best HP/torque, they can be used as a rough indication of fuel supply/injector adequacy. If you see the O2 sensor readings start to fall off as engine load increases, particularly dropping toward mid-800's, it may indicate a problem. If you are using DataMaster, be careful if looking at the injector "duty cycle" numbers... it isn't unusual to see them approach, or even exceed 100% (which is not possible) with no fuel delivery problems showing up in the engine operation.

Running lean will typically be accompanied by knock retard, so look there as well.

Absolute best way to check the adequacy of the fuel system is to get it on a chassis dyno, equipped with wide-band A/F logging, and look at the resulting curve of A/F ratio vs. RPM.

anmar A

so should i hook up a fuel gauge to the fuel rail? which brand would you recommend and how hard is it to install? is it just a bolt on?

Injuneer

You buy (or borrow) a fuel pressure test gauge. It will have an -AN connector that fits on the Schrader valve. You unscrew the black plastic cap from the valve, and screw the test connector on. Done. The connector has a small pin inside that depresses the valve core in the Schrader valve, so the gauge can read the pressure.

The test gauge should have a hose on it that allows you to pull the gauge between the cowl and the hood and tape it on the windshield.

Remember - this is checking the capacity of the fuel system, not the adequacy of the injectors.

I'm losing track of this thread... what mod's do you have on the engine? Are they significant enough to make you feel the current injectors aren't large enough?

PLEASE READ THE "STICKY" TOPIC - "YOU NEED A SIGNATURE"

https://www.camaroz28.com/forums/lt1...nature-879835/