1990 Chevy Pick-up MPFI

[duchacm]

I recently upgraded my 275k mile 350 with an Edlebrok performance upgrade to include performance heads, chip, cam, MPFI (from TBI)w/manifold, headers, roller cams etc.

Question:
A: Other than timing adjustments, are there any other adjustments necessary to maximize the power curve?

B: Is it beneficial to tune it on a dyno?

[dougbfresh]

The ECM was calibrated for the setup it came off of (not sure what year you pulled the FI setup off of), a new fuel curve will probably be needed for all your changes. You should get an aftermarket TUNABLE FI system since the older ECM were not field programmable like the new ones are (a whole chip was swapped out in the early systems). And yes, a dyno is the best way to do this.

[m1k3sthemannn]

I believe what he is saying is that he went from the 1990 TBI to Edelbrock Fuel Injection (MPFI) so it is either tuneable as is, or he sends some info to Edelbrock and they burn him one.

Yes, Dyno is the best way for you to get a correct calibration if it is not capable of being tuned by the user. Sending engine info to a company to *guess* or get "close enough" for it to work is nowhere near as accurate as actually watching the engine perform and adjusting tune to match best overall performance, regardless of what Edelbrock may say.

As to timing, correct timing has a lot to do with power, of course, and more timing doesn't equal more power, especially with efficient (read modern) heads.

[dougbfresh]

If it's all Edelbrock, I'm sure they have an opinion too.

[justen]

I would get it on a dyno and see where you sit at, Then you can see where you need adjustments for a custom chip. Edelbrock used to sell custom chips that they programmed right in their store.

[olddog]

Agree dyno, but make sure they use that wide band sniffer thingy on the exhaust. Without that reading you are not going to know for sure that the fuel is right. I expect most dyno shops have them, but I would not assume that to be the case.

[FieroSpeeder]

Originally Posted by olddog

Agree dyno, but make sure they use that wide band sniffer thingy on the exhaust. Without that reading you are not going to know for sure that the fuel is right. I expect most dyno shops have them, but I would not assume that to be the case.

That would be exhaust analyzers. And a majority of repair shops have them, that deal with emission failures.