RedHot85Vette

My '85 also starts, half a crank, any weather. Idle is a bit sticky and I can't seem to get it smoothe and steady. Take her on the road though, and I feel like she wants to play. At 33, I'm doing some preventive maintenance, updating, upgrading, repairing... I got the car from a nice senior gentleman who took good care of the car, it's very nice and everything works, but there were some odd things going on with the engine that I had to fix (somewhat funny things), but in the way of a complete tune-up and ignition upgrade. I did some mods but nothing abusive. I'm having fun with it and not getting deep involved in performance numbers. I want her to run nice, better than she's running now... and look nice. I can't help but love the ol' skool hot rod thing. But I'm not tearing into the heavy machinery to achieve my goals.

I have a ton of data about these cars. Dealer stuff. Articles. Test data that would really make you feel very proud to own one of these cars. History. Engineering. The Why's and Why nots. Great stuff that might answer a lot of questions about these cars that some may have. I have some great books as well.

Just out of the box, without doing a thing to them, they were just simply amazing. 150 miles per hour! The '85 in particular has some blow your mind test data. These early cars 85 thru 88/89 sent the Euro trash home with their tailpipes between their legs. They just couldn't beat the C4's by long shots, and that's dressed in dealer stock fashion, no mods. And even the other American cars couldn't beat them either. They were and still are, 33 years later, amazing machines without doing anything to them. Lingenfelter said they were the best platform to do anything with. So to said Callaway and a number of collectors. One collector standing in front of an '84, who had like about a hundred cars, a bunch of Corvettes, said in an interview that the white '84 behind him was his favorite car to drive. Just about everyone said something about how much Fun they were to drive. These cars have a Lot of Fun engineered into them. jeeze, I could go on and on and support my stuff with verifiable Fun data.

Ok, I'm driving off topic. How bout those injectors? Apparently I'll have to get the fuel pressure right. I'm right there with you and just have a brand new ready to be used fuel pressure test kit, and I'll be getting an adjustable fuel pressure regulator to ensure things are right, whatever "right" really is. By the way, what's a BLM? I'd like to know, will 22 pounders be Ok? They seem to be popular and most available for the '85. I'm thinking that was maybe the stock original poundage for these things. Does anybody know? And again, are 22 pounders Okay or Safe to use on the '85. Seems to me so far that the Pounds thing isn't exactly a critical number that could get one in trouble. John

Joe C

on the smooth and steady idle thing, a couple years ago, I replaced every stinkin bit of vacuum tubing as well as all fuel emissions rubber tubing. I can say, I had a noticeable improvement in idle quality - smooth like a new car. at the same time, I did a valve job, new injectors (bosch3's - 24#), new fuel filter, NOS, old school, delco, FPR, all the tune up stuff - plugs, wires, cap and rotor, egr valve, the works. everything came together and she runs as strong today with 160K miles as she did some 23 years ago with 33K miles. as far as 22# injectors, I'm guessing you'll need to bump the fuel pressure up a bit, but can't say for sure. you may need to look at the numbers. question, why not just get stock equivalent 24# bosch3's. Jon at FIC can fix you up with replacements. here's some good reading on the corvette TPI system and BLM numbers - http://www.jimsperformance.com/portinj.html

KyleF

22#ers are fine for a L98 if you are keeping stock H/C/I. If there is a chance you will go with a different set up in the future, you might want to consider that when purchasing injectors. You can always have the constant changed in the bin file and use a bigger injector.

Fuel pressure, like timing, will be a little different for each engine to get optimized. So, that all depends on where you want to go and how much dialing in you want to do. This is why guys running drag cars are constantly tweaking and checking their mph/ET. If all you care about is if it will run well, the later L98s ran 22# injectors at 43.5psi fuel pressure (make sure you take the vacuum line off to set it). This is where I would start anyway.

Now, you can get an ALDL cable online that plugs into a XP laptop and run a scanning software like WINALDL, or TunerPRO and see all your sensors in real time. You could also install a wideband 02 sensor. Eitherway, you just want to get things set so BLM's are in check and your narrow band 02 sensor sees cross counts. The beauty of Fuel Injection is, after that the computer will keep it in check.

I still encourage you to do some reading and gain some understanding before doing the install. Then if there are problems, you will be better prepared to address them. It will also give you a larger body of knowledge on the TPI for when (Not If) your next problem arises. There are links here that should be a really good starting point. As I said above, I think the Bosch IIIs will be a good choice for you.

Z51BOB

aklim

I think the issue isn't so much corrosion as how the Multecs are fuel cooled. IIRC, there is a TSB warning you not to use stuff that could damage the injectors that were fuel cooled. If the ethanol eats away at the winding insulation, it could cause a short. Additives are not free so you are having to dump a can every fill up. Would it be cheaper in the long run to just change them to ethanol resistant ones and not have to find pure gas every time?

RedHot85Vette

hmmm... Good Point! Who wants to carry around a 12 pack of additives when a 12 pack of beer is more desirable and less expensive. Be nice to just not worry and gas and go. But how do you know if an injector is ethanol resistant. Is that something that would/should be indicated in the specs? I'm thinking that my original injectors must be somewhat ethanol resistant for them being 33 years old and still ticking. I believe there's more ethanol in the gas these days than ever before and my poor ol' spitters are probably rotting as we speak.

I just bought a book, just got it, haven't turned a page yet (just moved into a new home, panic, chaos), but I'm looking forward to winter time studies. It's called "Corvette Fuel Injection & Electronic Engine Management". I also picked up an Air/Fuel Ratio Gauge and a Knock Sensor Gauge. I think they ought to be fun to play around with. The software talked about in this thread sounds extremely interesting too. Although I'm thinking the cost may not be too interesting.

I love learning about the car and it's innermost workings. Even if I'm only using it to take my dogs for a ride to the park. For several reasons I wasn't able to drive the car very much the past few years, but when I did, I swear that car was talking to me, saying, "I want to Play", because every time I did drive it, in my mind, out of nowhere, I'd get this thought, "this car wants to play". For a winter project, I've collected up some choice clean stock parts to build the whole upper part of the engine, from the intake up. Did you ever build models of cars when you were a kid. I did. Dozens of them. They were real popular in the 60s and 70s.I want to learn about, and get my fingers dirty on every piece of it. Slowly. Methodically. And with a good amount of fun in mind.There are other things I want to do as well. This car, my car, is going to be the last one I ever buy. And I intend on having a Lot of Fun with it, Piece by piece, bolt by bolt.

Damn that Ethanol!

John

KyleF

I got my scan tool set up for $140. Cable + Used laptop... and I can not only use it as a scan tool but I can save files on it to pull it up in the garage or use Google.
$140 is cheap to see everything real time.

ctmccloskey

The air fuel ratio gauge is not really needed in a C4 as the fuel system is pretty reliable and consistent. I have the AEM version of the air/Fuel Ratio gauge for setting up the various carburetors I own and use on my 500+ hp 427 Big Block in my 1968 C3. There it is very helpful as it shows you what is happening with the mixture at different engine speeds.

The suggestion to replace the vacuum lines is a good one as when I bought my C4 the lives had two breaks in it. It is a simple fix that makes a difference in your idle big time.

I know it is not popular to use somebody other than FIC for replacement injectors. I bought my set of Bosch injectors for less than what FIC charged at the time. The optional place is called "South Bay Injectors" and they are in the NYC area. Their phone number is 516-442-4707 and they have a web site as well. I looked them up and they list the new set of Eight-30 lb Bosch D3 injectors for your Corvette for $180. I have used these guys for a long time and have never had any kind of bad experience. The injectors they sold me work just great, just an option for you. Jon at FIC is a nice guy and a wealth of information and I have never said anything against them. The guys at SB have had lower prices on the same parts so I bought from them, their quality service and shipping has always kept me a happy Customer.

If I were financially concerned I would send one of these shops the injector set you have and have them analyzed and if needed fixed or replaced, this might save a few bucks.
Good Luck with your Corvette and have a Very Merry Christmas!

KyleF

A wideband O2 sensor is a big help when diagnosing overall engine health. I think it is very important to have one or the ability to read your narrowband. They make hand held wideband readers to plug to a sensor so you don't have to install it and can use it on multiple cars. A wideband is much more accurate.

To say a TPI is reliable, I would error on the side of WAS reliable. I have grown up with TPI and between the thirdgen Fbody boards and C4 boards, it is now becoming common to have injector and fuel rail issues at this age.

aklim

Check out the picture. I don't know if they can add more than the spec. So if the label says E10, it should be NO MORE THAN 10% or there could be issues when the customer comes back. Now if you put E85 in, it is on you. Thing is the injectors were designed to be fuel resistant but at the time, ethanol was not in gas. So the injectors were fine and will be as long as the gas has no ethanol to eat away at the coil insulation. If you use additives they might accelerate the eating of your coil insulation. Might as well change them and know they are not crudded up. There is definitely build up after a few years since I see the "before and after" test results. How much it will build up and how tolerant you are is another story. Never had any use for additives since I have yet to see an independent laboratory test with the methodology published Most of what they rely on is testimony based on the butt dyno.



I built model cars and airplanes with motors and gas engines but I failed at imagination so the car doesn't talk to me. I never believed in fairy tales of inanimate objects talking.

RedHot85Vette

Yes! Especially over the not so long term. You can save a lot of time and cash diagnosing your own junk and diagnosing it correctly. You must know how that goes. And the Fun you can have looking up all sorts of sff I bet. I just got today "1984-1988 Chevrolet "Y" Parts and Illustration Catalog". The real deal. Fantastic! I Love this sort of stuff and have quite a bit of it, some rare documentation too.

I wonder though if there's software for OBD I. 1985 was the last year for OBD I. I can read and translate the codes OK, and read voltages at the devices or within the harness with my DVM, but not get deep and dirty with anything else. And not so easy and intuitive as a computer that gives you instantaneous results and a whole pile of interesting data along with it.I made my own test ports for, so far, the TPS and the IAC. Pretty ingenious form and function if I do say so myself. Don't have to do anything but plug your meter in.

Sounds like you got a nice rig. I have a spare laptop. What's the product called? Where'd you spend your money at? Any other Special add-ons? hook-ups? hardware (memory?)? Any How-To Tips?

John

KyleF

I bought an ALDL cable from Moates.net and a used XP lapt top off Craigslist for $60. WINALDL was downloaded for free. I had to download a driver for the ALDL to USB converter. After that, set the right Baud rate for my 88's computer... and I was reading everything the computer could see in real time.

Not sure where the comment about OBDI ending in 85. OBDII functionality wasn't legally required until 96.

RedHot85Vette

Just got this book, and have been looking at data from multiple sources, including of course, this forum.

"Corvette Fuel Injection & Electronic Engine Management"

John

RedHot85Vette

I guess I meant 1995, but my car is definitely OBD I. I'm going to see what I can find that will interface my car with my computer. It would be great to see what's going on in real time.

RedHot85Vette

Just checked out moates.net ...wow! I say again... wow!

it's gonna kill my credit card!

Dreckerlin

Check other post: 85 injectors vs 86 injectors

aklim

But wouldn't they also be problematic from the standpoint that you cannot have ethanol? That means you have to trust that the station telling you that his tank has no ethanol really is true. Also you are now chained to those places so if you take a cruise, well, how to fuel up?

RedHot85Vette

I have an '85. I've gone over my engine and car with a fine tooth comb. I have disabilities which made a 2 week job for some a 4 month job and I'm not finished. I've done the entire ignition system including an Accel Super Coil and ignition control module, capacitor, distributor cap & rotor, some really awesome wires, no gap plugs (some names escape at the moment, meds I take wreck my memory), entire intake from air filter to throttle body, fuel filter of course and special oil change, every component of the cooling system including a 3 core aluminum radiator and all sensors 195 t-stat, 200 degree fan start, fan relay; Continental Goodyear (Blue) hose kit (every hose), water pump with high flow, I removed the AIR system completely and installed the bypass pulley, I had a prom made to eliminate it from the ECM.

Also I think the prom turns the cooling fan on at 200 so I can eliminate the fan switch. I removed the air conditioning system, installed bypass pulley, next will be the injectors and I'll test the FPR and consider replacing it with an adjustable, not sure about the Elimination of the EGR or the relocation of the MAT just yet, haven't done a valve job but sounds like a good idea for a 33 year old car, "every stinkin bit of vacuum tubing" with silicone or heavy duty (at the booster and cruise servo) , I made my own test ports for the new TPS and IAC making it easy to hook up my DVM, so I have some tuning to do the timing as well, I have a knock sensor gauge and an air/fuel ratio gauge to install, I have new MAF relays to install, I have a new battery, I'm installing a filter on the Bose relay, a new filter for the horn circuit, I installed all new split conduit, a new alternator and Gator belt (the previous owner installed the wrong alternator).

'm going to consider shorty headers cause they look cool, lightweight, better heat dissipation, some better flow, may eliminate the mufflers or custom design my own for fun, if I don't change the stock mufflers I'll get some nice chrome tips for them, new LED lights for the interior (less currrent draw and heat), got rid of the entire spare tire junk (everything!), I have new tires on 1995 rims with new lugs, I have new wipers, Lambo door kit, I'm going to get my power windows moving faster... it already has new brakes frm pvs owner, ice senior gentleman who took very good care of the car... car has beautiful fresh bright red (or flame red, whatever the code is) paint, a perfect comfortable cloth interior, covered the seats with some real sporty best quality seat covers, molded floor mats and US Coast Guard mats on top of them so as not to ruin the... solid targa top what seals perfectly in fact no leaks or rattles anywhere, The outer window seals are rotten so I'm replacing them...

hoa! got carried away, I know not everything is performance but it was fun thinking of everything,,, lighted rear view mirror from my old Lumina, fuzzy dice, HAhaha, Hey this board is for FUN too is it not?!?! ...there's more, headlights better than stock but not blinding to other drivers...Horns... I collected parts over a 3.5 year period while I couldn't drive it because of many (13 unscheduled) surgeries on my spine... in fact, I bught the car $5K, drove it home from the preious owners home about 115 miles, 2 days later started my hospital stay marathon, now I only drove it, supervised, about 75 miles, tops... this coming Spring I intend to be in better shape so as to be able to drive it myself... It's still Fun for me engineering the whole thing like building hot rod models when I was a kid...

believe there'll be a lot of additional horse power and torque when I'm done, I'l have to do the theoretical math and see how my butt hits the seat and then see what my butt dyno data churns out... I think my car will have a boss sound, and have a cool old school, hot rod look in the engine compartment, not perfect, more like a hot rod that's worked on and driven. Over the winter, I've got a very cool project in mind... but I'm not ripping the engine to pieces with new heads, a cam, or anything internal... no way... not my style and not something I can accomplish on my own... even so I have to get help with some things, my right hand is shot, makes holding tools, or being a lefty, very difficult... I even have the original cassette deck to put back in it... I really love this... stuff!

John

PS. whats' a BLM or O2 whatever. I want to get some of that cool software awesome software to see what's going on with my car real time. That's Awesome! Maybe I'll learn what a BLM is, Ha! For the '85 I keep coming up with 22lbs and 43.5 on the FPR, but it doesn't seem to be critical. I've read most of the problems with fuel injectors are install related.I'm not sure about what injectors to buy yet. I still don't know yet what the difference is between the inexpensive versus the expensive. I haven't heard from people who have bought the $69 dollar ones for example. I see a lot of great reviews everywhere for the cheap ones. I see the same specs for everything. Everybody is doing wonderful things, amazing claims, with the new and the refurbs... So... ???

RedHot85Vette

I was asking if the 1986 injectors would work OK on a 1985. Not the oppposite what you have written here. I don't have an '86, I have an '85. I don't understand what you're saying anyway. It's confusing either way. First of all, what did GM ship these things out with, OFFICIALLY? I want to see it in writing at this point, Make/Model, and specs, including specs for the FPR. Whatever the case may be, these cars were kicking azz at the track, dealer stock, and 150 MPH right out of the box, so the NOS really couldn't be half bad injectors. So I believe your suggestion has merit. It would also make things pretty easy. But it's hard to ignore the ratings and reviews and test data and all that stuff that clearly point towards getting, new technology, preferably Bosch III. I'm somewhat suspicious that the Bosch name is thrown around so much... Sometimes, I'm not quite sure if the injectors I'm looking at are Bosch, or Bosch Design.

I read somewhere that the '85 fired the injectors one bank at a time, not individually. I'm not sure if that makes a difference.

I'm not trying to be rude, I think you should check your own data since you got the years mixed up, you may have gotten everything mixed up.

I'm not certain yet, because I haven't seen any verifiable data, but for the '85, I'm leaning towards 22lbs/43.5, sitting still. Now, for what you're saying, I have to be concerned with the numbers about how they RAN!

Honest, it's interesting your suggestion about getting NOS. Why should I get NOS injectors (one hole)when EVERYBODY suggest New/Today's technology (4 hole)?

Why should I buy $169 dollar injectors when $69 dollar injectors will. Why buy New when I can get Refurbs a lot cheaper?

In the Spring I'll be able to test things with an FP Test kit.

John

RedHot85Vette

Hey Dreckerlin, I just found this at Fuel Injection Specialties, but I've seen it elsewhere, and thought you might find it interesting. This is their preamble:

"GENERAL - The following information on GM Port Injection and GM Tuned Port Injection Systems has been compiled from GM published material and as a result of discussions with our technicians who have installed these systems on a variety of vehicles. It is to the best of our knowledge accurate."

Then, about Fuel Injectors:

"Fuel Injectors - There are a number of Fuel Injectors on the market today the following injectors have been furnished on GM OEM systems: Lucas, Bosch, Rochester and Multec. The prices vary considerably and performance differences are hard to detect. Basically they are sized for application. The 5.0L injector is sized to deliver approximately 4.05 milligrams of fuel with a 2.5 millisecond pulse or 18.13 lbs per hr at approximately 36 PSI. The 5.7L injector is sized to deliver approximately 4.83 milligrams of fuel with a 2.5 millisecond pulse or 23.92 lbs per hr at approximately 43.5 PSI. This information is typical for all manufacturers and flow rates will vary slightly even between identical injectors."

Nothing is said about 22Lb injectors. It mentions 19's then jumps to 24's. But if 22's are used, will the ECM adjust itself for them. Thanks for that part Number by the way. I like to get data like that to work with. I'm going to look for that part. I believe Rockauto has a fuel injector refurb service. I think it would be an interesting experiment to try both the new vs the old. I only have a "Butt Dyno", as I've heard other's refer to it in this thread, but that's good enough for me. I want that "seat of the pants thrill" for me and my passengers. I may have to "Gear Up" for that, but that's another story.

Here's a very odd thing... I can access every web site on the planet except for RockAuto.com. I've given the problem to computer geeks everywhere but to no avail. One day, they, RockAuto was just unreachable. Then they came back for a short while, a week or so, then they were gone again. I've done all the common troubleshooting methods over and over... but I still can't access my favorite web site. Crazy!