SCPI to MFI

[lwcools]

One of the biggest problems that I have found with factory Hoes is the fuel injection. I have done all the standard tune up procedures and still catch the random misfire codes, system too rich, etc. codes via obd2. I have come to the conclusion that after 255k miles, its probably time to make the swap from the SCPI to MFI. The problem is, I'm lazy, cheap and only want to have to do this once during the course of my ownership of my hoe. That being stated, I don't mind loosening my grip on my wallet for the right part with the best reputation. So, for those of you who have made the conversion happen in your hoes, what brand MFI conversion injectors did you use and what have your results been? Satisfied? Any further issues related to the injectors?

Right now, I'm looking at AC Delco or Delphi. My plans for the truck are keep it simple and near stock for the next year, after that, the future of the powerplant is a complete build or possibly crate swap to the Chevrolet performance HT383E that Jegs offers. The crate engine is blue printed to run on factory injectors. Any help/ advice will be greatly appreciated.

 

[lwcools]

Update on the above...

I went with AC delco, and opted to do a complete intake gasket set instead of the upper only kit that comes with the new injectors. I scheduled some time at my buddy's shop for last week to get the swap done after hours. Sadly, about 36 hours before I was going to get in to the shop, the lower intake gasket failed and I lost about 2 gallons of coolant in the oil pan. My $400 fix jumped now to a $2400 fix. I've decided that since Vortecs really hate water in the oil pan, I would go ahead and do a preventative refresh (new bearings, rings, cam bearings, etc...). While its torn down I'm going to throw a mild cam and some headers at it.

So, a new question is posed (maybe I'll get a response this time...lol) Does anyone have any suggestions on a mild street cam that I can run without changing lifters, valve springs and having the computer reprogrammed right away? My budget wont allow for a new tune on the computer for a couple of months, so if I need a reprogram but can wait, I'm ok with going that route.

 

[lwcools]

In yet another twisted turn of events, the heads are shot and the block needs to be bored. Looks like I'm doing a full out build, sooner than planned. I'm going with a set of new casting vortec heads that have been worked out to have the same specs as the Dart Iron Eagle ss heads. Cam will be comp cams xtreme energy 480/488 lift and the headers are decidedly the summit budget shorty truck headers. I'll be bored .0020 over and swap from traditional dished vortec pistons to full valve relief flat tops. The blueprint on my setup shows an expected 308 hp/459 tq at the flywheel.

 

[keep_Tahoe_Blue]

Whats up man, The replies here can be hit or miss iv noticed. Ad thanks for doing leg work with a cam.. iv been lurking around trying to find one that will drop in without doing anything crazy also. Well please include a lot of pis of this build as I'm at 190,xxx and plan on pulling it out at the end of summer... could us all the help i can get lol

 

[lwcools]

@keep_tahoe_blue I agree on the replies, I guess it comes with the territory on the whole forum thing... Lol. With respects to the cam, I went to Comp Cams and did a chat with their tech advisors. For my setup (replacing the heads etc) I was able to go with a Little bigger lift than what factory vortec heads will allow. That being said, they did give part numbers for the hardware needed to make the bigger cam work with factory heads. If your interested, I can post them here when I make it back home from work. You can also go to the cam quest software and put in all the details of your ride and they will help you choose the right can for your rig.

 

[keep_Tahoe_Blue]

That would be awesome man! I def want to throw a cam in there... not looking to do anything crazy just a cam that would work with the heads not being modified.

 

[lwcools]

The cam part no 08-500-8 from Comp. To make it work in stock heads, the tech said I need these part numbers too:
New valve springs 26918-16
Retainers 787-16
Valve locks 648-16.

After tons of research I've found that the max lift on factory everything is .470. The lobe separation angle (LSA) will need to be 111-112 to keep from modding the computer. The rest becomes semantics. For what it's worth, I would be fully prepared to replace heads. Factory vortec heads really like to crack, for no good reason...

I went with the "small Kit" from Comp, that has the cam, lifters, and timing chain/sprocket kit. the part no is sk08-500-8, priced out at just $559 from compcams website

 

[lwcools]

A couple other parts/part numbers that are going into this build adding prices for my own notes but you might find the info useful:

Summit Shorty Truck headers SUM-G9016 (199.97 Summit.com)
ACDelco SCPI->MFI conversion injectors 217-3029 (262.78 Amazon.com)
High Flow Throttle blade from CFM-tech.com (39.95 CFM-tech.com)
Black Bear Tune (240+50 core from Black bear performance.com)

 

[lwcools]

One more update before I go for the first start up...

All of the engine work is done and its waiting to go in the truck next week. The crank ended up being ground 10/10 and was salvageable, as were all the rods. We ended up doing a .020 over bore and using speed pro power forged pistons (sorry no part numbers or price on those yet). The final blueprint on the engine using factory air intake is 310/460 (a skosh higher than pre build) at the flywheel. The BBtune isn't factored in to those number either. I'll be sending the computer to black bear next month, and I'll be adding a CAI and dual exhaust with cherry bomb vortex in the upcoming months. Last thing, Ill be posting some pics of the damage in later today or sometime this week.

 

[lwcools]

Here's some pics of the damage...

 

[lwcools]

Here's the new heads and the links to some of the other new parts..

http://www.summitracing.com/parts/sum-g9016/overview/year/1996/make/chevrolet/model/tahoe

http://www.summitracing.com/parts/cca-sk08-500-8

http://www.summitracing.com/parts/slp-h345dcp20/overview/make/chevrolet

http://www.amazon.com/ACDelco-217-3...1616&sr=8-2&keywords=fuel+injector+conversion

 

[lwcools]

I guess I forgot to update this previously, but, I got the truck back about 6-7 weeks ago. It runs like a dream on the highway, but until I get my tune done, I wont be feeling any of the power she makes. Right now the factory PCM has it feeling a lot like stock with more umph on the highway. Once I get my tune, I'll be visiting a dyno locally and getting a couple of pulls in to see what's actually hitting the ground.

 

[pikeucf]

Under going a very similar operation at the moment myself. I was intending on doing a rebuild. But when I dropped off the heads to have cleaned they found I had 3 cracks. The cracks are exactly in the same spot yours are cracked. Long story short, I bought a crate engine. Who knows what else would have been cracked the further I crept down this rebuild path.

Although my injectors were doing just fine, I also decided to update to the new spider injector after reading everyones take on the subject. Everything slowly adds up.

Best of luck... let me know if I can help in anyway, I've been submerging my brain on this crap for a few weeks.

New Engine...Now what?

 

[lwcools]

Sounds like your in the same boat I was a few months ago. I read your thread and I think your doing all the right things. My baby is running again, like a champ, all the factory stuff seems to have mated well with the upgrades for me. Unfortunately, my build was done on a paycheck to paycheck budget so I'm still adding little bits and pieces as I go. The best part is that the end is near for my journey.... I only have two more components to address: the EGR valve and computer tune. My Trans seems to be holding well despite added hp/tq but it will be getting a rebuild and new torque converter next year.

 

[lwcools]

For anyone reading or up on my build, or following the thread, I got my Blackbear Tuned PCM today. Like a kid on Christmas morning I ripped into the box and immediately started playing with my new toy. The PCM they delivered was obviously used and was still pretty dirty. Also in the box was the complimentary BBP decal (optional at time of order). I kept my old PCM and paid the core as just in case kind of move. After swapping the computer out, which took all of 5 minutes, I fired up the ol' hoe and she roared to life like never before. First fire was impressive, and the lag that was present before was gone. After a few minutes of idling while I loaded my kids in their seats, I hopped in and took her for about 25 mile test drive. Immediately I noticed the pep that I had been missing, and as the drive went on I noticed that there was more than I had expected. The shifts were firmer and passing now a breeze. Before, I had a surge in idle and at very light throttle, both of which are now gone. Bottom line: My first impression of the BBP tuned PCM is that it is everything I had hoped for and more. If anyone is on the fence about using them, or leery about doing a mail order tune, these folks are top notch. Jarrad in customer service/sales has been my point of contact and tremendously helpful in the process. I'm tempted to yank the chip out of my T/A and see BBP can do anything with that!!

 

[lesterl]

NICE!!!!!!!!!!!!!!!!! Me Loves toyz....