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Is there a good write on converting injector system
I did not see/find a solid write up on converting the fuel injection from the sfi to the mfi type. I did find the links to things like the http://ww2.justanswer.com/uploads/Bl...conversion.pdf article. Helpful yes but kinda lacking for the home do it yourself person. The link for 1 of the replacement kits
while valid seemed pricey and appeared like several other delco brand ones could be just a valid for less money. There is mention of a bracket change but no note if that is included or purchased separately and what that part number would be.
My conversations about the idle issue I have been dealing with and follow up testing lead me to conclude replacing this should correct the problem in several ways and instead of going with the current sfi updating to mfi would benefit my boat hauling too. Can someone point me to a solid write up on what parts I need to purchase in order to complete this. I really hate digging into a project and stopping because I missed a part and need to put job on hold for its arrival.
This is for a 1998 Blazer “w” code vin. I follow this with an additional item. I am considering just doing a rebuild on the whole thing but clueless where to even start as far as finding the correct kit. I attempted to read up on it but apparently GM had 2 plants making these engines with a couple of variations and can hardly figure out how to determine what I need in the first place. Reason for this line of thought, minor oil leak lower front. Checked oil lines to remote filter and look good. Center bottom is a mess tho and really think that front main seal is culprit. Lifter tap at start when cold (typical) and just the age of engine with over 200k on it.
I’ve taken a few pics of underneath chassis. Will keep high resolution so can see details better.
Top quite clean Note oil behind main pulley Closer view angle to catch oil remote lines Oil ends up dripping off bolt- 1-2 drops 2” round per use when I park back home
MPFI conversion involves only replacement of the poppet injector spider with the MPFI spider under the plastic cover of the intake - nothing else, and no different calibration - not one thing - plug and play. I think there are plenty of write-ups with photos on this site on replacing the injection spider, but I'll look for one. Brackets either come with the new spiders (AC Delco), or they tell you that you need to buy them (some others). If you end up with the AC Delco they will give you all that you need including the gaskets.
Yeah, oil lines don't look so bad IMHO.
I see you've been reading the article on the internet on rebuilding 4.3s. IIRC it was dated mid-late 1990's and the early 4.3s were a hodge-podge of parts. Fortunately the later 4.3s are a lot simpler. By 1998 the vin W motors (L35) all used the same metric block and crankshaft and rods and balance shaft. Main differences at the 1998 point would be use of roller rockers vs non roller rockers. Then in 2001 the knock sensor mounting hole size on the block was changed. The L35 was replaced with the LU3 in 2003. It came with the MPFI injectors and no EGR, otherwise virtually identical and uses the same rebuild parts. And that takes us through the end of Blazer production. Below is a good place to buy engine rebuild kits - looks to take the exact same kit from 1996-1998. I have used them quite a few times in the last 25 years.
Thank you! This will help. Injector kit wise I really did not understand why say for example the Delphi was about 100$ more than the Delco which seems to come with the bracket. You did assume correctly on the reading up on 4.3 liter GM engines the blazers and several other GM auto’s use. A couple of those midyear changes must’ve been hell for the mechanics. Just the variations of the same engine almost seems nonsensical. Why have 2 plants make the power 2 different ways, dumb and dumber. Guess by what I’ve read got lucky ending up in a 98 but I picked 98 or better due to 4 wheel disc brakes standard without even knowing about the engine stuff. I feel a bit better that a long time member like yourself could not find a good write up in forums on the injector change over. Saw several threads about it, few links on parts and such but no start to finish type write up I got used to seeing with some great photos and notes to keep a person on track. Guess I can do one here in a bit when I get the parts ordered unless someone snuck one inside a build they did. I attempt that route, no luck and I admit poor “google-foo”.
On that rebuild, you have any clue if doing that type of project is better than say just going with a restored crate type engine- by this I mean my skills, knowledge and tools are lacking but my mind, body and soul are willing. I know doing this basically myself would save me a ton of money I think...if I can do it and not screw it up and make things worse which from some of my reading can happen. Stupid things like even wrong torque on a few bolts can f-it up from what I read. Fear I might bite off more than I can handle or with the internet is it quite doable with decent head on your shoulders and common sense?
Part ordered from Amazon- arrives by Friday 3/29 afternoon. Looked like best deal and correct. Seems to be full kit with bracket and gaskets.
Looked to be best product for price. Full kit? It seems so. Will try to do a full little write up with photos when I install it.
Crossing fingers this is correct. Looks it and seems to have everything needed to do the swap. Guess any missing gaskets or such I will source locally.
Last edited by Trukntigger; 03-27-2019 at 11:30 AM.
Reason: Ordered part- update
That spider is correct and will have all that you need.
LIM gaskets is where you will need to be particularly careful - even with a long block you will need to switch over your intake manifold. I definitely know there are howtos on the LIM gaskets. Pay particular attention to cleaning junk out of blind bolt holes, running a tap through all bolt holes, wire brushing the bolt threads clean, using Teflon head bolt sealer, using only the rubber coated metal Fel Pro gaskets, and torqueing with an actual inch pound torque wrench in steps in sequence to the proper torque - then repeating the torque next day.
I have a Goodwrench rebuilt in mine. Here's the best deal for your 1998. 3 year/100K mile warranty, no core (with Jegs), no shipping, and you get to keep a nice plastic shipping crate for your old engine. Mine came with plastic timing cover and new oil pump/pickup, even though it doesn't indicate that it will. Make sure you replace your radiator and document it (no matter what) if you want the warranty.
I completely rebuilt my original engine (spent $2500+ and an incredible amount of time on it) because it was a 65,000 mile original. In a truly blonde moment I set it up for disaster (several thousand miles later) by thoroughly priming the oil pump/engine with the intake not on yet. Ended up buying the GM engine because I decided it was time to start driving it in the snow that year - instead of having it sit in the garage and work on it. (I had previously burned through two 1-week vacations during Thanksgiving and Christmas). If you're interested in the story, just search for my first post that I started with a kazillion pages and views - it's pretty funny for me to go back and read. I have learned a lot about Blazers since then! I still have the original engine in the shipping crate - just needs disassembly for cleanout and a crank kit, but I've never found a use for it since then and its kind of a bad memory!
Is there a write up this install of the LIM gasket? This the stuff that always bites me in the butt afterwards. I do it but do it wrong and cause worse problems...kinda like your engine rebuild. Man still 2200 for a crate is almost more than I paid for the Blazer and still need the extras. No wonder so many just grab a boneyard engine and use till she blows.
That is a exactly what a guy like me needed. A very big thank you! Now if the parts would arrive, it’s late- typical. Then earlier today my son borrowed my Blazer (to get a part for his broken jeep) and brought it back broken. (Apparently a bolt that retains the front right brake caliper bracket fell out?) So now got to grab my wife’s car early in morn and get the bolt and get back so she can go to work and I can get my so so running Blazer operational to drive to get the rest of the parts..and a few tools. Deep well sockets..grr. Going to be a long few days in the man cave garage, oh well beats painting bedrooms.
You're right about Handymanlyness.com for step by step instructions. Good pics and instructions if you're doing a rebuild or just a partial repair. I used this site as one of my resources when I rebuilt my 4.3 in my 2000 Blazer last year. Kind of funny story now, not so much at the time, but I used his rear oil seal and oil pan instructions as this is a critical step in making sure you avoid leaks. When I installed the flex plate, I used his picture and instructions when I installed mine. In his photo his flex plate shows the counterweight facing out, away from the motor, so I did the same. When I installed the motor the bolts to connect flex plate to torque converter wouldn't reach. Realized I put the flex plate on backwards. Pulled motor and when I turned the flex plate around stamped in bold letters are the words "This Side Out". Another idiot moment in my rebuild. Don't know if the weights are different on some flex plates or not. But had a 50/50 chance to get it right and still messed it up.
You're right about Handymanlyness.com for step by step instructions. Good pics and instructions if you're doing a rebuild or just a partial repair. I used this site as one of my resources when I rebuilt my 4.3 in my 2000 Blazer last year. Kind of funny story now, not so much at the time, but I used his rear oil seal and oil pan instructions as this is a critical step in making sure you avoid leaks. When I installed the flex plate, I used his picture and instructions when I installed mine. In his photo his flex plate shows the counterweight facing out, away from the motor, so I did the same. When I installed the motor the bolts to connect flex plate to torque converter wouldn't reach. Realized I put the flex plate on backwards. Pulled motor and when I turned the flex plate around stamped in bold letters are the words "This Side Out". Another idiot moment in my rebuild. Don't know if the weights are different on some flex plates or not. But had a 50/50 chance to get it right and still messed it up.
Ditto for the Handymanlyness write-up.
Look carefully at the instructions for how to loosen the bracket for the power-steering pump. I wasted a bunch of time on that by not reading the directions carefully.
Got everything gathered up (I think) to finally start this little project which I hope remains just that and not a new headache. Even got my sons friend to loan me a very nice snap-on 1/4” drive in inch lbs torque wrench. He also lent me a Milwaukee cordless with some attachments to clean and prep the surfaces for new gaskets. So popped the radiator cap to find ...green??? Call me surprised, already been converted over to the standard antifreeze and not dexcool. Sweetness by my standards (not a dexcool fan, sorry) but had to go back and swap the dexcool I purchased for the green stuff. Will attempt to take some pics here and there so you all can tease my poor mechanical skills. I’m no blogger type person so don’t get your hopes up too much. Ok, off to give this job my best.
03-26-2019, 12:26 PM
Is there a good write on converting injector system
