SCI/MPI

[Bloke]

I am wondering if anyone has updated the crappy 8 injector nozzles to the actual 8 injectors. If you did was there a better throttle response, better mileage and any HP increase with the new system?

The original stuff still works but thinking of just changing it out for the new type.

I am the original owner and i am still waiting for this to go out. LOL

 

[stutaeng]

What engine?

 

[b454rat]

Assuming the truck in ur sig, so a Vortec. I have personally haven't did the switch, but I've read that it idles smoother, better MPG, better starts, and it might feel like more power, but that could be just a side effect lol. I have a 98 Tahoe I just got, has lil over 200k on it, and PO told me he put one of those in it. If it wasn't for the exhaust leak, couldn't tell it was running. It idles silky smooth. If anything else, knowing that they won't go bad like the stock poppets is worth it IMO.

 

[stutaeng]

Yeah, if you are referring to the infamous "spider injector" upgrade, it is definitely worth it. I changed mine a few months ago because of a lean code and was a huge improvement in idle quality. I used the local parts store BWD brand, but it looks just like the other brands. Has some translucent green plastics were the injectors go in. The engine is almost imperceptible that it's running and I've got Flowmasters or something like that the PO installed. Prior to that I had a little shake at idle, just thought it was normal. Now idles like a new engine.

I can't say power is up or mpg is any better, however, as mine was not running optimally prior to upgrade. Maybe power is "slightly" better, dunno.

 

[east302]

I did it on my 98 Tahoe and K1500, both while doing the lower intake gaskets. On the truck, I thought at the time that it was a noticeable improvement. Smoother throttle response but still lousy mileage and maybe slightly better acceleration.

So I did the Tahoe and noticed no change whatsoever.

My gut says that any improvement I saw in the truck was just by my replacing injectors that were marginal to begin with.

 

[alpinecrick]

I am wondering if anyone has updated the crappy 8 injector nozzles to the actual 8 injectors. If you did was there a better throttle response, better mileage and any HP increase with the new system?

The original stuff still works but thinking of just changing it out for the new type.

I am the original owner and i am still waiting for this to go out. LOL

No. The MPFI is less susceptible to being clogged from dirt than the CSFI. Unless an injector or two is leaking on your CSFI your not going to see a gain in performance.

 

[alpinecrick]

If we changed the fuel filter Often & Frequently there would probably never be a need to change out the original spider. My 96 (259K) has the MPFI,, my 97 (165K) has the original CSFI.

 

[Bloke]

Ya its, 5.7 in my pic. Of course when i bought new and it was stock. I would get about 17/18 hwy and 14 ish city. Now with over sized tires, brush guard and 4.10 gears, superchips reprogramer its about 11 and 12 mpg or 180 miles in town and about 220 is on the highway. Really thinking about going back to a 3.73, doing 75 i am hitting 2200 rpm. I dont have a misfire and idles pretty good. Only have 139k on it.

Well i just ordered the upgrade and got AC Delco sure would have loved Delphi. But in the last 3 years, i have done paint job, major front end work, escalade seats in leather, center console, AC all new etc. Got save some money somewhere. I guess and easy 8k.

Be about the 27 or 28 for the parts to get here so maybe by the 31st it be installed. Only thing left to take care of the steering with that dead zone between 10 and 2 oclock, lower control arms, inner/outer tie rods. Engine and tranny have been untouched sans the usual maintenance.

 

[HotWheelsBurban]

Crappy gas will f up your injection poppets too. On the first 99 5.7 vortec Burb we had, in 07 and 08 when gas got really high, we decided to go to Walmart gas stations because they were cheaper. Those out there who have Burbs understand, when you're having to get 30 or 35 gallons at a time,cost is a consideration.
Truck ran okay at first ( my family was spoiled on what gas to use cause our 90 R2500 Burb 5.7 would run great on just about anything)(TBI motors aren't as picky). As things got worse, the fuel pressure regulator went bad, the poppets clogged, and eventually the cats got ruined. We did the cats ourselves, but the other stuff got done by a shop. Ended up being around 3 grand before it was done.....and yes I also replaced the fuel filter.
Current Burb is less persnickety about its feeding, but I try to stay with Shell. Kroger loyalty rewards points help some on the cost, but of course gas isn't as expensive as it was then.

 

[df2x4]

On that note... I had a similar experience running ethanol free gas from a local supplier. Didn't actually hurt anything mechanical, but my mileage plummeted in both trucks. I switched back to regular 10% ethanol blends from top tier suppliers and everything went back to normal. Now I won't run anything but top tier in my vehicles. If it's not on the "Licensed Brands" section of this web page, I don't want it.

https://www.toptiergas.com