Small update. Alternator did come in but was the wrong one. I have (hopefully) the correct one showing up today, so after work that will be going in and I can finish wiring up my fuel pump jumper switch. Maybe the vette runs tonight? I will test for fuel pressure first before hooking the fpr fuel feed back up of course.

 

Hi, congrats on the 84... just a couple of things, if you don't mind answering:

1 - Fuel Pump: You said he replaced this... the factory fuel pump for the 84 flows 14-PSI. Have you measured the fuel pressure?

2 - Fuel Filter: I see posts above about the fuel filter, that video is correct. You should ideally replace both rubber lines going to and from the filter, as well as the filter, and I would also make sure to check that the lines going to and from the fuel pump have also been replaced.

3 - General Fuel Questions: couple things... it didn't make total sense so I want to make sure I understand. Are you using the factory fuel pump on the Holley carb? It might be too much, normally they want 6-PSI. Another question... if you have a pusher pump somewhere in-line, and you're SUCKING fuel from the tank... as opposed to using the in-tank pusher pump... then it's possible you could be sucking air in from your lines. I've had this a couple of times over the years... first example is a 1973 VW Bus that I bought (still have it). We installed an inline 6-PSI pusher pump before the carb in place of what would have otherwise been a mechanical pump. Neither before or after, could I get the VW Bus to get over 30 miles an hour... I just assumed it was because the Bus was slow as ****, turns out, the rubber lines going from the tank to the fuel pump were so old, that I was actually sucking air through the lines along with the fuel. At no point did I ever have a fuel leak, but I was literally sucking air with the fuel... it was crazy. I replaced the rubber lines... immediately I could get up to the break-neck speeds of 70 miles an hour in 4th gear. These carbs also usually have a filter built in (at least I know the older Rochesters would) that was almost like a piece of pummice sometimes, like a washable stone filter.. but that was really just to prevent things that made it past the normal filter.

4 - Distributor: Another thing you want to consider... I know you have the carb running on there... but what about ignition. I saw that you said you changed the wires and plugs... is this still the HEI Computer Controlled distributor? Without an ECM, or all the things connected to it, you're not going to get any ignition timing, and the car will probably drive horribly, if at all. Your distributor (unless you said you swapped it out) has an ignition control module that the ECM would use to control the spark and ignition timing. You can STILL technically use this with a distributor, but generally, you'd also need other inputs like VSS, MAP, tach, etc... and without that, it doesn't know what's going on. So I would recommend you convert to a vacuum-advance distributor if this is something you're looking to do. Even if it has an MSD box on it, that's just going to give you multiple spark discharge, but it's not going to give you a timing advance. So let me know if that's already resolved.

5 - Finally, what is your ultimate goal for it? There are a few aftermarket kits out there that can give you back computer control and fuel injection. One such example is the FAST EZ-EFI 2.0 system which gives you ignition timing, and will control a 4-bore TBI unit that fits a carburetor intake. Realistically, this will probably give you way more performance than you might get from the CFI. But if you decide to switch back to CFI, we can help with that too. You can probably get some decent money for your TBI units on eBay as well. Something to think about.

 

Hi- don't mind at all. Going to copy and paste your entry so that I have a little easier time answering, as well as matching my responses to your questions.


1 - Fuel Pump: You said he replaced this... the factory fuel pump for the 84 flows 14-PSI. Have you measured the fuel pressure? No, I have never had fuel pressure to even measure to do that.

2 - Fuel Filter: I see posts above about the fuel filter, that video is correct. You should ideally replace both rubber lines going to and from the filter, as well as the filter, and I would also make sure to check that the lines going to and from the fuel pump have also been replaced. - Noted, thank you.

3 - General Fuel Questions: couple things... it didn't make total sense so I want to make sure I understand. Are you using the factory fuel pump on the Holley carb? Yes, but it is a Edelbrock carb actually. It might be too much, normally they want 6-PSI. Another question... if you have a pusher pump somewhere in-line, and you're SUCKING fuel from the tank... as opposed to using the in-tank pusher pump... then it's possible you could be sucking air in from your lines. I've had this a couple of times over the years... first example is a 1973 VW Bus that I bought (still have it). We installed an inline 6-PSI pusher pump before the carb in place of what would have otherwise been a mechanical pump. Neither before or after, could I get the VW Bus to get over 30 miles an hour... I just assumed it was because the Bus was slow as ****, turns out, the rubber lines going from the tank to the fuel pump were so old, that I was actually sucking air through the lines along with the fuel. At no point did I ever have a fuel leak, but I was literally sucking air with the fuel... it was crazy. I replaced the rubber lines... immediately I could get up to the break-neck speeds of 70 miles an hour in 4th gear. These carbs also usually have a filter built in (at least I know the older Rochesters would) that was almost like a piece of pummice sometimes, like a washable stone filter.. but that was really just to prevent things that made it past the normal filter.

4 - Distributor: Another thing you want to consider... I know you have the carb running on there... but what about ignition. I saw that you said you changed the wires and plugs Plugs no, but I did move the plug wires to the correct points on the distributor, as every one of them were wrong. Doing this allowed for the the first time the car to fire up with the carburetor swap, something the PO never achieved... is this still the HEI Computer Controlled distributor? No.. it's a mechanical one Without an ECM, or all the things connected to it, you're not going to get any ignition timing, and the car will probably drive horribly, if at all. Your distributor (unless you said you swapped it out) has an ignition control module that the ECM would use to control the spark and ignition timing. You can STILL technically use this with a distributor, but generally, you'd also need other inputs like VSS, MAP, tach, etc... and without that, it doesn't know what's going on. So I would recommend you convert to a vacuum-advance distributor if this is something you're looking to do. Even if it has an MSD box on it, that's just going to give you multiple spark discharge, but it's not going to give you a timing advance. So let me know if that's already resolved.

5 - Finally, what is your ultimate goal for it? There are a few aftermarket kits out there that can give you back computer control and fuel injection. One such example is the FAST EZ-EFI 2.0 system which gives you ignition timing, and will control a 4-bore TBI unit that fits a carburetor intake. Realistically, this will probably give you way more performance than you might get from the CFI. But if you decide to switch back to CFI, we can help with that too. You can probably get some decent money for your TBI units on eBay as well. Something to think about. Ultimate goal is get the car restored to OEM or near OEM and be a weekend cruiser with the wife/date night car. We both love the older Chevy's, with me its the Vette and she had a 79 Camaro back in the day.(if I end up keeping the carb swap) with maybe some brake upgrades and possibly power upgrades. LT1 or 4 or even LS3 swaps have crossed my mind. A nice sound system and wife want me to paint it House of Kolor Wild Cherry Candy. The interior plan for now is to restore the light gray OEM interior with new or nice, used pieces. Carpet, seats, center console, etc.

 

Ok, I'll focus on this. If you hear the pump running and priming, but you get absolutely no fuel pressure at all... then I would focus on that first. There's any number of things that could have happened... but I'd also question whether or not the fuel pump is even installed correctly. Does the fuel pump look like this:



Or does the outside still look like this?



Reason I'm asking is because if he just changed the pump, he may have reused a lot of other things, and the whole pickup assembly should be changed when a car has been sitting for such a long time like this. It's like one of the easiest things to do in a Corvette, so I would recommend it.

My suspicion is that there's something messed up in the pickup... but just to be sure, check fuel pressure at all the points. If you haven't already... check fuel pressure actually at the pump... hook up a longer fuel line tube directly to the pressure line from the pump, and check the fuel pressure. If you only have a Schrader-valve style fuel pressure gauge, they have ones from Harbor Freight or eBay that you can get which have adapters: https://www.ebay.com/itm/167238351027

Again, with the factory 84 Corvette fuel pump, you should be getting 14 PSI.

If it's good at the pump's pressure line, then check it at the fuel filter... and if it's good there, then check it further on. But again, if the pickup / fuel filler area looks 100 years old, then he didn't change the pickup, and honestly, if you're not getting fuel just get the whole kit.

$50 for a brand new 1984 Pickup: $38 for a new 14psi 1984 Pump:

BUT... and there's a BUT in there... if you don't think you'll ever go back to the 84 Cross Fire Injection system (and are missing all of that stuff anyway), then it's probably not worth trying to now... just being honest. My 84 Corvette came with it all there, and just badly needs things replaced, but it's a solid car. If the engine harness was hacked up, and it was missing the CFI intake / plenum, and TBIs... I don't think I'd even bother. At this point, I'd be thinking about what my long-term goal would be. There's a lot of aftermarket fuel injection systems that you can go to... anyway, I mention that because if you plan to go to one of those, you might as well NOT go with an 84 fuel pump, and instead, go with a fuel pump from a 1985 and newer (which is rated at ~45 PSI). That way you don't have to do the job over again.

There's a lot of different kits out there. Personally, I'm more partial to the FAST EZ-EFI 2.0 system because it uses all the old GM connectors and sensors, and keeps it "kinda" GM looking to an extent, but a lot of these systems (complete with everything) are usually around $1,500 bucks. Sometimes you can get lucky... like this Holley Projection 4D system for $550 - https://www.ebay.com/itm/335921132877

Anyway... if you did decide to go back to Cross Fire Injection, you can probably find a lot of the parts if you want it...

 

You keep mentioning that the 84 pump puts out 14 psi. I'd love to know what brand pump that is.

I've tried AC Delco, wix, Airworx, and a slew of others I can't even remember the brands of and never got over 13psi from any of them. Most were in the 11 to 12 range. So I went with an '85 pump to feed my 383.

After about 2007 or so I've had to throw a new pump in every 3 to 6 months due to that ethanol crap in everything. Even when I finally got a 100% gas option finally in town i still have to toss a new pump in every year or so, or at least replace that 2" long rubber hose (pump pulsation dampener) off the pump to the metal tubing of the pickup assembly when it turns to jelly and splits.

I'd estimate I've been thru at least a good dozen pumps of different brands since ethanol blends became the norm. Like you said tho, luckily it's about the easiest part of a C4 to replace. I can have a pump swapped in 12 to 15 minutes now days and I always carry a spare, with a sock and pulsation tube

 

Haha... it's SUPPOSED to put out 14 PSI. Originally the range was 12-13, but from what I read in a TSB, the regulator was changed to 14 PSI to eliminate some instances of stumbling above 4,000 rpms.

For the fuel line, I purchased several feet of NBR, which has high resistance to the acidic nature of ethanol. I never really use what comes in the fuel pump kits, because you don't ever really know... but I always end up putting together kind of a hodge podge of whatever came with the pickup tube, the fuel pump, sock, etc. and my own stuff. I also use a lot of RTV sealant (specifically the kind with fuel resistance), and of course, I use my own fuel line.

One thing worth mentioning... this little guy...



... you don't really need this anymore. This was designed (as you know) to dampen the pulses of the fuel pump... which could be very noticeable and extremely annoying. The older design of most fuel pumps in the 1980s absolutely required these, as you would get pulsating (which this device solved). The newer pumps are completely different in their design (pretty much anything made after the late 90s), and they don't require these anymore at all. You can still use them of course... but it's unnecessary for most of the newer fuel pumps.

If I'm being honest though... if I had a car that I was keeping totally pristine and original, I'd probably still install one... hahaha.

 

I have actually never heard the fuel pump prime, much less run. That is why I am installing a jumper switch to the fuel pump relay. Is there a better way to power the fuel pump for those of you with a carb swap? I still need to inventory all the parts he pulled off, but everything is supposedly there for the crossfire, minus the engine harness that is now useless.

Not sure if the whole pickup was swapped out or not, but I will check tonight after work. My plan was to install the jumper switch and then go back and check the pins on the harness for power, unless of course I hear it kick on. I probably need to sit down with the service manual and figure out which wires I can use for the ignition and fuel pump. So far all I know is to jump pin G2 to 12v switched for the fuel relay.

 

Hi, to answer the question, I just responded to this in another thread... easiest thing is to jump the ALDL connector lead with a simple wire directly from the battery. Easy to do... my response covers that here:

New C4 owner issues - CorvetteForum - Chevrolet Corvette Forum Discussion

My daughter also covers this here in a different car (but exact same thing) @4:12 in this video:



But sort of a bigger thing to talk about... what are your ultimate plans for this car? I ask because my personal opinion is that you should try to figure this out first. The way I see it... you're kind of stuck with someone else's problem. I know you were helping a guy out, and that really sucks what happened to him, but you don't want to go down the path of hodge-podging a car unless you have to. My advice is to absolutely decide first what you want to do with your car...

1 - Finish converting it to a carbureted motor.
2 - Convert it back to Cross Fire Injection.

My personal advice is to decide that first... before you start fiddling with the car. Without any kind of direction, you're wasting a lot of time, and likely to get really frustrated. Regardless... if the car has been sitting a long time, you really want to check out if he even changed out the pickup. The pickups are cheap enough that if you're going to change the fuel pump, change the pickup too. I'd personally recommend repairing or getting a good used replacement wiring harness for the Corvette. There's plenty of people who have done conversions and don't need the harness anymore. Just my advice...

 

Yes, I already have plans to jump the ALDL to see if I can get fuel pressure, -.after work, which is only a few hours away. Actually watching the clock here being impatient.

Ultimate plans for the car is to restore it to a solid driver. As for finishing the carb swap or converting back I am not sure. Right now I am more in line to see if it will run with the carb, because despite my efforts thus far, I have been unable to source an engine harness, so I couldn't use the crossfire parts right now anyway. I am just working with what I have for right now. Later on once carb is sorted I plan to inventory all the crossfire parts, (and all the other parts) clean them up and either sell them to go towards an LT/LS swap, or if I don't think I will get enough $$ from them I will direct the funds into resto items like new carpet and seats.I plan to repaint the car myself ( I can't wait for that part)

 

Oh and to answer your question about the fuel pump assembly/pickup, I checked while I was on lunch break. The entire assembly has been changed, so it looks like the top picture.

 

Ok, good... then next step is testing via the ALDL.

And if you plan to swap the engine anyway... then I wouldn't put any effort into re-sourcing CFI stuff... because it would be wasted effort.

The motor should run just fine with 6-psi of fuel pressure, your Edelbrock carb, and a vacuum advance mechanical distributor with ignition coil. Just need to eliminate everything else in the engine bay that has nothing to do with any of it... otherwise it'll just confuse you.

 

I am pretty sure she will run, now driving is another story. It has an aftermarket shifter in it from B&M that my wife hates, not to mention looks completely out of place, and I am not even sure the kickdown to the carb is hooked up. I don't think it is now that I think about it but the PO said something about the tranny blowing up if I try to drive it - because something wasn't together with a cable that he could not figure out. I will worry about that later, right now I just want to hear her run. I am wondering with the carb swap and harness cut if I get fuel tank reading, speedometer, tach etc on the instrument cluster?

Some side questions:
Best oil to use?
Best coolant?
Braker rotor part#
Brake pad part#

 

If you don't mind me asking... how much did you spend on the car? The car would have come with a 700R4 automatic transmission, which has an output shaft that's unique to the Corvette. They aren't hard to rebuild, and don't cost a whole ton, but a shop will probably charge you around $2k, if you bring it to them in your arms (yeah, they're heavy). But if you need them to remove the transmission, that's a whole other thing you're going to have to worry about too... do you have an engine hoist, do you have the space / room to pull the transmission? Some things to think about.

Anyway, the reason I ask all this stuff is... if the car is really, really, really shot... then I would personally just get the engine running, and sell it on eBay. Because, these C4s are selling for rock-bottom prices right now. I saw a 100% factory original 1984 Corvette with 7,400 miles... and it was pristine... factory showroom condition, needed nothing, was just serviced and had new tires. It sold for $8,000 bucks. And please don't be offended by me asking any of these questions. I ask because I'm 47 years old now. I can afford to buy a total piece of **** and drop $20k in restoration parts and not lose my shirt. But through most of my late teens and early 20s, I was always buying really turd cars... like my 1982 Pontiac TransAm, and then doing stupid stuff like buying Hooker Headers for it when it had 150k miles on it, and barely ran. So just really plan out and know what you want to do with this car.

In my line of work... (which used to be computer programming, now I sit in meetings all the time), there's a common theme among a lot of the nerds I work with. They tend the marry the very first girl that gives them the time of day. Usually, that's some really aggressive woman that's very demanding, and bosses them around for the next decade of their lives, and then they eventually get a divorce, and it's a mess. Getting a project car... even a "free" project car, can often be like that. Don't let your emotions from those clean C4 Corvette lines trap you into spending the next 10 years of your life savings on something that is a complete piece of ****. There's lots of C4s out there... find the one that attracts you, don't wed yourself to the first C4 that gives you the time of day.

I assume you already have a clear title in your name? Because if not, that's another big no-no... you never want to spend money on a car that you don't physically already own... that's a disaster waiting to happen.

 

Yes I am familiar with the 700R4, my 85 Caprice had it and it went to **** one day. I pulled it myself and did a rebuild on it. I hear ya on just getting it running and unloading it, and I may do that. I saw one on cars & bids that was turn key pristine go for around 8k as well, and yet another one here local that was pretty solid for 5k. As I do with any car, I like to learn the car so I can do stuff with it. Ideally yes I would love to have a nice condition C4 but that will have to wait until I have more garage space. I got this one cheap enough and enough parts to go with it that if I can get it running and driving, and flip it and sell the other parts, then it would indeed be a way into a nicer C4, preferably an LT1 or dare say LT4 car. I could also just give it to the wife lol.

I have a clean title on the way ( I went yesterday to DMV).

 

So working on the car, the ALDL is nowhere to be found. There is a connecter under there that has lettering on it, so maybe that is it? I have already pulled the radio out too, looking everywhere under the dash for it. I have a jumper wire ready to go from the battery and the new alternator is in, with the fun exception of the pully wheel is too small. So the belt is barely on there. I tried to change the pulley wheel but I can't get the one that is on there off.

 

Here is the only connector I see that looks like anything.

 

Read through most of this, not sure if it was covered but can you hear the fuel pump prime when key is turned on? Is there power going to the fuel pump relay on both ends?

 

No fuel pump prime, but me and my daughters boyfriend just put a voltmeter on the harness at the back where the plug is and we get 12 volts on the left side of the plug, blue wire. Car does fire immediately with ether.

 

ALDL should be mounted right there on the knee bolster above the right knee like 3 inches from trans tunnel. Should be able to scrape your knee on it while driving if a deer jumps in front of you. Or be able to bend down slightly and look down and see it while driving

If not Bubba has moved it back under the dash somewhere

 

yea.. he definitely moved it...