aklim

Mine never did and definitely not after I changed the fuel pump so not sure. There is a sump and if it is gone, maybe.

ch@0s

I replaced my pump with a 255 because of starvation issues.

aDigitalPhantom

If you need a fuel pump I would get an EP381. While looking for a better pump then the factory part for my project I found that is supposed to flow 50-60gph at 80-90psi.

aklim

Racetronix has a nice kit. If you bought the EP381, wouldn't you have to buy the pump and go get your own parts? You definitely would want to get new bolts and a gasket and fuel line unless you insist (for some unknown reason) on reusing the pulsator. So what is the reason for getting the EP381? Is it that much better for his application?

cumbercr

These graphs don't help. You need to data log. Export the log to an Excel file. Then sort the file by TPS Voltage. Now look at the O2 voltage where you have WOT (4.5V TPS). Come back and report what you find.

DanielRicany

Here is another spread sheet with the O2 voltage this time. I'm not really sure how much O2 voltage variation makes a significant difference, but maybe you can tell me.

Thanks.

cumbercr

At WOT your O2 voltage should be in the upper 800's. Yours is higher which indicates you are running a little rich. It does not look to me like the engine is leaning out.

DanielRicany

Well I did another 2 data logs in 3rd gear. Here are the results. Looks like MAF gms/sec is not dropping off.

aDigitalPhantom

If you cant accept my opinion why do you need to reply?

I prefer to buy local, and racetronix is not local. My local parts stores had everything needed on the shelf. Unless the gasket for the sending unit is in bad shape or leaks there is no reason to replace it. Also many here for some reason (unknown to me) would prefer to keep their car all Gm and only use AC Delco parts the EP381 is an AC Delco fuel pump.

The fuel pump has a new piece of hose and clamps to attach it to the sending unit in the box. There is no need for new bolts unless they are damaged, and even then the bolts are easy to find. If you want metal clamps instead of the plastic clamps that are in the box grab a set of FI clamps.

aklim

I'm trying to understand your reply. Hence the questions.

I usually don't reuse gaskets when they are that old. I prefer to get new gaskets instead of hoping the old one holds. Been bit too often.

They are easy to find but if a kit is there, why not use it? OTOH, if the GM product is superior, I would go with that. If I was restoring a car, I would get OEM and the right part that it came with stock.

Kinda why I asked. I want to see if it is a performance gain or better product or just personal preferences. When I buy parts that are for performance, I buy for performance and price is also considered. If restoring sure

aDigitalPhantom

Sorry about my last reply I had a bad first half of my day yesterday.

If the gasket were the o-ring there is no way I would consider reusing it. On my car at least the gasket for the sending unit was not cracked or dry, and was is good shape. I don't know if the PO ever replaced the gasket, but I doubt it. The EP381 was not used in Corvettes, it was a 96-97 truck pump. It is also normally (from my looking) about 30$ cheaper. I don't know what pump the L98 cars used, but the LT1 cars used an EP376.

I cant say if it is a better product then some of the other options. I do know that the factory pump I was hoping to use, because I had already replaced it not long ago did not work for my car. For me at WOT the fuel pressure would drop about 20+ PSI and keep dropping unless I stopped trying to accelerate. No I don't have the LT1 anymore, and I don't know how much power the engine has. I will know that after I get more miles on the rebuilt engine, and fix a few suspension issues.