Upgrading to mpfi should i do the lower intake gasket?!

[L31MaxExpress]

At least in a van you have some access to the back of the engine once the doghouse is off. Had a company van years ago ( the older style unibody van though) and that's how it was. The express model is the same way?

Yes it is

 

[97K1500Silverado]

Should I even bother with MPFI upgrade? 5.7 with 215k runs great. Any benefit to mpfi when the old spider is working fine? I’ve read some reviews where the mpfi caused issues when a injector stopped working.

What’s the best price / place to order? Delphi or AC Delco?

My truck had intake manifold gaskets done 80k ago and all seems well.

 

[1997]

Should I even bother with MPFI upgrade? 5.7 with 215k runs great. Any benefit to mpfi when the old spider is working fine? I’ve read some reviews where the mpfi caused issues when a injector stopped working.

What’s the best price / place to order? Delphi or AC Delco?

My truck had intake manifold gaskets done 80k ago and all seems well.

imo, no point, i did my 97 cause the spider crapped out (and intake gaskets), performance increase, um no.

 

[df2x4]

FWIW, both of my '97s (around 150K miles on each) are running 100% factory original fuel injection parts with no issues.

 

[Pinger]

If it aint broke - why fix it?

 

[97K1500Silverado]

If it aint broke - why fix it?

Some reviews - it runs so much better, more responsive, etc. Guessing something was wrong with original Spider injection. I’ll keep running the ol poppet mechanical injectors [emoji106]

 

[TXStepside]

i upgraded to mpfi when i did my lower intake 97 5.7 152k. truck was much more responsive. might as well knock out the intake and clean it out while youre in there

 

[GirchyGirchy]

I changed mine. I was losing coolant and oil and there were signs of antifreeze in the oil (analysis). My truck was on 45,000 miles so pretty certain they were the originals. They were and needed changing.

If you (or anyone else) decides to do this job and doesn't have a scan tool - this worked for me.

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That's a good idea. When I did mine (traces of coolant in oil), I just took a ton of pictures and measurements.

As long as the engine doesn't rotate during the job, the distributor should just mesh right back in the same way. However - MAKE SURE the oil pump engages and the distributor is all the way in! Somehow my oil pump rotated slightly while I had my intake out, so when I put the distributor back into the right spot, it wouldn't seat. If I got the oil pump drive to seat, the distributor was off by one tooth. So I had to use a long screwdriver to slightly turn the oil pump down in the engine.

I planned to replace my injectors but found that had already been done...but they hadn't used the upgraded IM gaskets, so it had a slight leak.

 

[Coveman]

I did the whole kit-n-kaboodle at once, at 20 years n 140k. not sure what the age and milage of your rig is. I have a 99 and was watching for signs of lower gasket failure, sure nuff after a 16 hour trip I smelled coolant. I did rad, heater core, water pump, hoses and that quick connect all together.

Also, for you folks that have an oem cali set up you probably already have mpfi from the factory. My truck’s spider was a leaky mess, on the scanner it showed fuel trim was -40 so, yeah it was a good time to swap that too.

 

[Steve A]

Here's some good reading about stabbing the distributor in a Vortec small block.

https://www.gmt400.com/threads/installing-and-correctly-setting-a-vortec-distributor.6884/