RetroRanger

For simplicity you can leave the DVCS bypassed and connect the distributor connected to manifold vac only.

i would def rebuild the carb replacing all gaskets and make sure there is no leak at the inlet.

either set the points or replace w a kit like jaunty linked to

set the timing

jaunty75

Thank you. Counting my mother, this is now two people in the world who think this.

Olds64

Shawn, to set the choke depress the gas pedal to the floor once with the engine cold as Jaunty said. When you look at the carburetor the choke valve should be nearly closed. If not, loosen the three screws holding the black choke housing on the side of the carburetor and rotate the black cover. The choke will open or close depending on which way you rotate the black cover. There is a measurement given in carburetor rebuild kits which is the distance between the choke valve and the airhorn (carburetor body).

I suggest rebuilding the Qjet too. Just make sure you schedule an entire Saturday to do it. You don't want to leave the parts sitting out for a couple of days; or 18 months like I did when I rebuilt an Autolite 2100 once, because you can easily loose your place.

Shawnk111

Okay, time to show my inexperience with carburetors again lol. So, I spent the day cleaning and rebuilding the carb. Really wasn't very dirty inside... Used the kit, so replaced all gaskets and the needle seat and the needle...

I adjusted the float so that it was 1/4in from the top of the float to the edge of the bowl when the needle was seated.

I reinstalled the carb and gave it a go... I figured it would need to turn for a min to get gas in it again... Well after a while I started getting gas coming out the top vents on air horn.. I searched onlinebfira reason why, and people were saying tye needle is sticking on the seat? Guessing I have the float adjusted wrong? Any advise for this part? Planning to get back at it again tomorrow, but I'm done for the night and hopefully you guys can give me a tip or two lol. Not a hard job, but still not one I want to do 10 times. Thanks in advance!


Also... Worth mentioning, I lost the bracket for the choke. The one that attaches to the choke on the inside of the carb body... A rod runs from that up to the main butterfly... Couldn't find the part of a similar replacement anywhere, so I made a little bracket for It... Seemed to work okay .. doesn't seem to cause any interference, but hell I'm not sure the choke is working the way it's suposupp to. It's a little warmer than usual but once I press the gas choke flies wide open.

Olds64

Can you provide a pic of the choke bracket you made? Sounds like something isn't right if the choke opens when you depress the gas pedal. You should be able to adjust the choke with the engine cold to close the choke when you depress the gas pedal.

You definitely need to make sure the needle sits on the seat properly. Double check the way the needle hangs off of the back of the float. This is easy to get backwards. There should be a diagram in the carburetor rebuild kit that will show you how it all fits together.

Good luck!

Shawnk111

Olds64 thanks for the reply.

I took the carb back off this morning, and I re adjusted the float height. Made sure the needle was sitting right. Put it back together and put it back on the car. No overflowing issues this time. Last time it cranked and gas started spitting out the top and pooling around the accelerator pump shaft. This time it was fine, it cranked, no fuel came around vent holes or accelerator pump, but still no start.

Cranked and cranked and a buddy sprayed some starting fluid in and still no go... Almost seems like it's a spark issue now... I had it running the other day (poorly) before I removed the carb... I had just replaced the points, the condenser, the rotor, the cap, and the coil. I replaced the plugs and wires a week or so ago...

Maybe the timing is wrong? I've never had to adjust timing. I understand the procedure, and I do have an old timing light I bought years ago for a time like this... But on my main crank pulley, there is no nut or anywhere to put a socket or a wrench to try to turn it... And I don't see any markings for the timing... So how the heck do I set the time, I'd I can't get it set to tdc and there's no marks for degrees? I've been googling this a lot and haven't found any info. Thanks you all

Olds64

Shawn, there should be a timing tab on your engine here:



You might have to get some engine degreaser and spray the timing cover to find it under 48 years of grime.

I suggest you do the following:

1) Have your buddy crank the engine while you hold the #1 spark plug wire against the frame, you should see it arcing. This will confirm whether or not you have spark.
2) Have your buddy crank the engine while you rotate the distributor clockwise (as viewed from the top). This will advance your timing. If you rotate it counter-clockwise you will retard the timing.

Shawnk111

Olds64 that is a pretty engine.

I did find that tab.

So I pulled the#1 plug wire, stuck a plug in it... It was long enough that I could look at it while I cranked the enfine... No spark at all.... I did replace the coil a few days ago... I tried putting the old coil back on but no change. Gonna do some more research and see what else could make it to where I get zero spark... My understanding is that there should be spark even if the timing is off right? If I understand correctly, then there is spark but it's just not sparking at the correct time... So I suppose the timing wouldn't be the issue for no spark

Fun71

Check to make sure you put the points in correctly, then check the dwell. Sometimes it's a little thing, like forgetting to tighten the points mounting screw and the points close completely.

Shawnk111

Well hard to say what the initial problem was... I changed back to the original coil... I put the old points back in... Went to crank it and nothing... Then I realized that I forgot to put the rotor back on... Hahahaha.... Well it fired right up... Was not running right . I turned the adjuster screw to the left about half a turn and it smoothed out... Purring like a kitten now...

Went to go for a drive to see if it drove okay under load, but no sooner than I pulled out of the alley did my temp light kick on... Great.. so I parked her again... I thought I had a leak in the radiator. There's a good radiator repair shop here and supposably the guy has been here for years and takes it apart and acid dips it and solders any leaks. So I'll give him a call tomorrow and see what that's gonna cost me. I figured that's way better than buying a crappy AutoZone radiator.... Probably be a few days before it's done but I will give you guys a heads up once it's done

Olds64

Glad you got it running. Let us know when you get the radiator back.

BTW, the engine isn't mine, it's just a pic of an Olds small block I found on the internet.

Shawnk111

Radiator is okay. Thermostat was broken. Replaced thermostat, rad cap, and fan clutch. No more overheating.

Still stalling under load. Idles fine. Revs fine... Drives up the street okay, but if I get on the gas it just wants to cut out. Trying to go up a hill it stalls 2 or 3 times.

I knew there was a small slit in the accelerator pump diaphram/rubber plunger... My carb is a 4mc. Only replacement plunger I could find was for a 4mv. A bit shorter but thicker. It fit okay but there was no change in drivability.

I was still thinking fuel pressure... I stripped the fuel filter housing on the carb, so I removed that filter and epoxied it closed. I now have an inline filter before the fuel pump. I noticed it is always full of bubbles. So I thought maybe the pump was bad... Installed new pump this morning. It defijdefinhelped because the fuel filter is now full of fuel and no air bubbles... So I thought that probably fixed it... Went for a ride and it still stalls like crazy. Can't make it up the smallest of inclines...

My timing is not correct. I've been kind if winging it on the timing... Started with the points... I just adjusted them with the engine running until it sounded the best ... Then I adjusted the actual distributor untill it smoothed out. Just tried to find the sweet spot.. got it to purr and go for a drive. Starts okay, and then starts to stall under load...

My DVCS is broken. The connectors on the top we're broken off. I was going to attempt to repair it, but the rest of the plastic crumbled away and there is nothing there to work with... Currently, I have the transmission vacuum line going to the manifold, and I have the distributor advance line going to the ported vacuum on the front of the carb.

I thought maybe I had the timing off and when I'm getting to higher rpms the advance was too much and made it stall... Just a thought, but it struggles at low rpms under load and stalls...

Also it could just be my imagination, but it seems to run okay even if I get on the gas, for about 5min... Then I can barely touch the gas without killing it... Or it could be that the first part of my drive is flat then I get to the hills later and start having issues.

I'm gonna keep working on the timing and whatever else I can think of, but any advice or info from you all would be appreciated. Starting to get kind of stumped

Olds64

Did you use a timing light to set the timing and a dwell meter to set the dwell?

Shawnk111

I bought a timing light a long time ago just in case I ever had a car that needed one... With that said, no I have not used it. I honestly don't even know how to use it hahahaha... But I just need to Google how to use it. I know u hold the light at the tab on the crank pulley...

I can't find a dwell meter anywhere in town... And again it's not a tool I've ever heard of let alone know how to use... Another thing I'd need to Google once I actually find a dwell meter...

I've just been adjusting it until it smooths out and sounds good. Nothing has made much of a difference no matter how I have it set accept that it idles smoother... I'm working on getting some help but gang the timing adjusted correctly

Also, one thing I did was to replace the plug wires a while back. The ones I got we're the ones where you make your own ends for them. I never cared much for those kind and maybe I messed one up. I'm considering putting the old plug wires back on just to take it for a test drive and see what happens

Olds64

This is what you need to do a tune up. Use a timing light, vacuum gauge, dwell/tachometer and a set of feeler gauges.

1) Take your distributor cap off and set your point gap with the feeler gauges.
2) Reinstall the cap and start the car to set the dwell.
3) Use the timing light to set your timing.
4) Adjust your fast idle with the dwell/tachometer.
5) Use your vacuum gauges and set your idle mixture screws to maximum vacuum.
6) Reset your fast idle since it might be a bit off after adjusting your idle mixture screws.

Here's a dwell/tachometer. Surprisingly, I couldn't find an analog ones ( I guess they don't sell them anymore).


Here's a well reviewed set of feeler gauges:


Here's a vacuum gauge:


You can check the auto parts store to see if they have any of these for rent, but I don't think they have them anymore.

Let us know when you have the tools and are set to do the tune up.

Shawnk111

Thanks olds. Im definitely still going to do all of that stuff to get the timing right.

Today I hooked up a 1gallon gas can direct to the fuel pump. I drove around with that under the hood and it ran flawlessly. So apparently my problem Is in the fuel lines or further back. Should I be looking to drop the tank and clean it? If I remember correctly, the service manual had a pic of the inside of the tank and it didn't look like it would be as simple as just scrubbing it out... Plan to replace fuel lines as well? Anything else?

1967Supreeeme

Did you drain that stale nasty fuel? I also like to pull the tank sending unit and make sure the pre filter "sock" aka strainer is not plugged up with varnish, or missing.

Shawnk111

Pulled tank today. Sending unit appears to be destroyed by rust, and the tank is completely full of rust also. Im going to buy a new tank, but I can't find a sending unit anywhere.

jaunty75

Go to rockauto.com and search under 1971 Delta 88. They show availability of a sending unit. I think the 88s and 98s used the same sending unit. It's just that rockauto and other parts places don't always have their parts properly catalogued.

That sending unit is like the one that was in my '67 Delta 88. It's got a round rubber float that moves up and down with the level of the fuel on a shaft. No one makes new ones. I had to put a sending unit like the one shown at rockauto into my '67. It works well enough.

The rockauto sending unit doesn't look like yours. But it should be a drop-in replacement. Note also that rockauto shows availability of a fuel tank for the '71 Delta 88, but it's only for station wagons, which is weird. You'd think there'd be a lot more demand for tanks for the full-sized non-wagons rather than the wagons, but who knows.

Shawnk111

Thanks jaunty. I have to wonder how important they canister or housing around the float is... I cut the rest of the rusted canister off. The bottom plate is still there and that keeps the float from sliding off the bottom of the pick up tube.. I've got it cleaned up pretty nice and it seems to work okay... Just wondering if I can use it like this. I was considering using some flashing and epoxy to make a new canister, but it almost seems like it's just not necessary. But I figured I'd run it by you guys first since you know more about it than I do.

jaunty75

The purpose of the canister is to dampen the effect on the float of the sloshing of the fuel around in the tank to prevent the gauge needle from bouncing around as you drive over bumps and around corners and stop and start moving at stop signs and signal lights. The gas tanks did not have baffles. With the replacement sending unit, there is no dampening as the replacement is designed for use in a tank with baffles. But having the fuel gauge needle wave around at you a bit is a small price to pay, in my opinion, if the alternative is no fuel gauge at all. I've had the replacement sending unit in my '67 for 10 years now, and I've much appreciated actually having a functioning fuel gauge.

Shawnk111

Thanks jaunty that makes a lot of sense. I do believe my tank is baffled. It appears to be divided into 3 sections by "walls" inside the tank. I think for now, I'll try my sending unit and see what happens. Best case scenario my gauge bounces around some. Worst case, I have to buy a new one. Thanks again. I'll update you all once the tank is taken care of

Shawnk111

New tank installed, running pretty well. Going to a shop that has a dwell meter in a few days to get the timing all done right.

Couldn't find a replacement gas tank so I ended up getting one for a 71 GTO.. of course my sending unit didn't fit so I got one for the gto also...

I'm wondering if there is a difference on the signal from the old sending unit. I put 13.5 gallons in and it's a 20 gallon tank, but the gauge reads a bit below 1/2... Gonna just fill it up and see where the gauge is at...

Shawnk111

Even with a full tank it does not go past the 1/2 mark

Olds64

GM fuel sending units should be 0-90 ohms. Remove the fuel tank and leave the fuel sending unit hooked up. Have a buddy swing the arm from full to empty and check the fuel gauge for proper functionality.

Why did you replace the fuel tank? The original fuel sending unit was pretty rotten but from the pic the original tank just had a coating of surface rust inside. Pics can be deceiving, but I would consider your original fuel tank a candidate for repair instead of replacement.

Shawnk111

Well the tank was baffled. So I couldn't really get in there to clean it. I did my best with chemicals and water to flush the tank out. Even drilled a huge hole to drain it (later plugged the hole)... Ended up with a pile of rust chips as big as a basketball... Reinstalled tank and it ran great for a day.... The next day it died every couple minutes when I was taking my step daughter to school. Ended up having to walk her the rest of the way there so I just ended up getting the new one. The new unit seems to work, just doesn't go past 1/2 tank. I'll drop the tank again soon and have another look

Olds64

Shawn, it may be too late but apparently you can get tanks specifically for our cars. At least, ones that were the same as the ones used in our cars:

https://www.rockauto.com/en/catalog/...fuel+tank,6268

I knew the 71-76 Custom Cruiser tank was available but according to RockAuto they carry the tank for the 71-76 Delta 88/98. The picture is even accurate. Maybe someone else can confirm if the Spectra GM40K is a direct replacement.

Shawnk111

Haha yeah I guess it's a little late. I had a Spectra gm34m . In the future I will probably end up putting the correct tank in it . This one was close but not quite a perfect fit.