Okay,
I tried to make a thread on this before.
Usually when I start the car and drive it, 2 miles down the road the car starts to shudder and hesitate, and throws me a code 33 and 24 (MAF low voltage and VSS)
Turn the car off, turn back on, light goes away and drives fine for the rest of the day.

Tonight, it is starting to happen more and more.

I replaced both MAF relays, I have to assume it is the ECM. Why else would it be okay after you shut off the car and restart it...

I have a 305 prom on my 350.... if you think this would have anything to do with it.

 

I swapped out the ECM... the one I bought made it worse... got another one... and it is back to the original problem..... So now... I am thinking it is the prom...

anyone have a prom laying around?

 

If you are getting the same error codes repeating, the ECM is probably not at fault unless the I/O hardware has failed. If that happened, it probably would remain that way and not "reset" itself after cycling the power.

The fact that you are getting the '33' with a 305 program is not unexpected. The 305 uses a lot less intake air at a given RPM than a 350, let alone the extra few inches created from boring. The ECM thinks that what the 355 is sucking in is too much for a 305, and that is correct, as far as it knows.

The VSS issue is separate unless you have somehow mixed a 2,000 PPM VSS into a vehicle expecting a 4,000 PPM input, or vice-versa.

Getting the correct program (MEMCAL) for your engine and year is going to be a good idea, but important information has been left out. We can read that the car has a 355 TPI, has a manual trans, but don't know if there is air conditioning, two cooling fans, what injectors are installed, whether it has 15" or 16" wheels, and several other factors which would affect the PROM selection.

 

I know we have been Pm'ing but here is another recap.

355 roller block. Aluminum Corvette # 128 heads, w/ angle plugs. L98 corvette cam, with 1.6 RR's AIR system is inop. The TPI is bone stock, with MAF. The injectors are 19 lbs, all checked good with resistance and are not leaking. T/B is 48 mm. However coolant line has been bypassed.
Headers 2055's... which are 1 5/8" primaries with 3" collectors. The Y-pipe is 3"s all the way through. 3" exhaust all the way back... no cat.
Not sure if it matters but the rear end is 3.42's and the tires are 16/245's

I would like to have an adapter so I would not have to solder in and out the eprom. So I could eventually upgrade it, however, it could wait as long as the car is reliable.

I still need a 350 knock sensor and ESM will get that next weekend or if anyone has one chime in

I have a spare 7365 computer if you want it. It does not have the same memcal as the 7165 but I am sure you already knew that. came off of a 2.8 88 computer. But if I am not mistaken could be used for TBI?