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Good evening all, finally got my 75 Delta 88 out the backyard and on the road. Made an 8 mile maiden voyage around the city to see what she'd do; did well initially but started to stall and finally die out when coming to a stop. Will start right back up, but high revs and some pedal assistance is needed to get the ol girl going. Once she's rolling, it rides like a dream.
Anyone have an issue like this or suggestions? It almost feels fuel starved, just wanna gather as many scenarios as possible.
Thanks in advance!!
First, how old is the fuel, and how long has the car been sitting unused? Carb rebuild or tuneup may be in order.
Next, check idle speed and vacuum hoses.
so far on my end, new AC Delco plugs/wires (gapped at .035) new distributor cap/ignition coil, new EGR, new PCV, cut new vacuum lines to carb (still need to replace brake booster lines, I believe the PCV line to the left of the fuel filter) adjusted mixture screws on carb 3 turns CC, tightened up secondary doors on carb, adjusted idle speed screw, just had motor/transmission mounts replaced Monday.
Gentleman I purchased car from installed a new gas tank and it was pretty much empty upon arrival.. so far only using conventional gas (87 non-ethanol) while I work out the kinks.
I personally wanna do my own carb rebuild, as this is a learning process project, but finding one is proving to be interesting.
Do the one on the car. If you have mechanical skills, armed with a 75 factory shop book and a good carb kit there's no reason you can't do it. Worst part will be finding a bucket of carb cleaner big enough to soak all the carb parts.
Try this on a long shot. Even though EGR is new, disconnect and plug its vacuum line and see if anything changes.
Will def give that a try. It's time to cover it up for the winter anyway, so now is the perfect time to tear into it..I have my hefty service manual in hand. Don't know how guys maneuver around these cars without it.
Thanks for the input, can't wait to see yours put together and some rolling shots
X2 on fixing an original carb, they are factory set-up/designed for the engine, transmission and options on that car. A generic rebuild will never work as well. If you haven't done a Quadrajet, read about, understand and be careful with the fuel inlet. The fuel inlet nut/carb threads are about the most you can destroy.
Get a manual, high quality kit, float and choke pull-off if needed.
I agree with sugar bear about rebuilding your original carb. Also could be float level too high which could cause flooding, or some other cause of flooding.
You didn't mention replacing the fuel filter. I have a 75 that would run on the road then just die like it ran out of gas. I replaced the fuel filter and that cured the problem. Just another possibility. Just curious, why did you gap the plugs at what you did? The decal on my fan shroud says gap at .080.
Just curious, why did you gap the plugs at what you did? The decal on my fan shroud says gap at .080.
Midway thru 75 model year Olds issued a tech bulletin to gap HEI plugs at .060. The .080 gap was more than HEI in daily service could handle especially after plugs had a few thousand miles on them.
OP, you can open your gap to anywhere between. 045 and .060 and get a little more benefit from your HEI.
Remote possibility of an HEI module breaking down but that usually shows up as poor high speed performance or the engine won't start at all.
Last edited by rocketraider; November 8th, 2021 at 06:34 AM.
You may have opened up the mixture screws too much. Put a tach on it, screw them in until they lightly seat, then turn them both out 1.5 turns. Start the car with the tach connected. Keep turning both of them out 1/2 turn at a time. The idle speed should rise each time. When the idle speed stops rising, turn both of them in 1/4 turn. Then you are done. Reset the idle speed as per factory spec and see what happens.
UPDATE: after many a page turner, many different Quadrajet Power lifesavers 😁 and a steep learning curve on staked screws, my original is back together..almost. In doing the shaft bushings I bent the shaft going back in so the throttle is sticking..I used another base plate just to get my car rolling again and now I'm running into a hard start problem. Its almost fuel starved but it didn't have that problem with the original base plate. If I add fuel to the top of the carb she starts right up and will run forever. When I find time, I will re gap the plugs or get new ones altogether as this may have fouled out during all the cranking and restarting. This has been a fun journey as I've never had a chance to rebuild a carb before and seeing how all the linkages work is fascinating.
Keep turning the wrenches guys and gals and have fun with these classics. Timing chain, water pump and radiator is next on the list
I would attribute difficulty starting to fuel starvation or timing. Especially if pouring fuel into the carburetor gets it to start. Have you tested the fuel pump? You can disconnect the fuel IN to the carburetor and put the hose in an empty can. Cranking the engine should give you a solid stream of fuel.
I would attribute difficulty starting to fuel starvation or timing. Especially if pouring fuel into the carburetor gets it to start. Have you tested the fuel pump? You can disconnect the fuel IN to the carburetor and put the hose in an empty can. Cranking the engine should give you a solid stream of fuel.
Recently changed out fuel pump but as the saying goes, they don't make em like they used to. Im on the same page as you and to be honest I've done so much testing, tuning and swapping it may just simply be low on gas 😂
When I get some time off im gonna play with the timing, check plugs, and put some fuel in her.
thanks for the suggestion
Make sure your egr valve is not stuck open. Sometimes a chunk of carbon will get stuck in the pintle of the egr valve and hold it open. This creates a giant vacuum leak at idle. There are two ways to check either pull the valve and inspect or check the the temp of the valve at idle. If water sizzles off of it at idle it is most likely stuck open. At idle if you haven't driven the car the valve should about the same temp as the intake manifold. Once the valve opens it gets as hot as an exhaust manifold due to the exhaust flow trough the valve. If there is carbon holding it open. The easy fix is the hold the rpm up around 2k and apply manifold vacuum to the valve to open it all the way and allowing the carbon pass. Or the valve could just be mechanically stuck open.
Well that took a turn 😁 couldn't meet my goals with the original 350 so out with "olds" and in with the new. Blueprint 350 mated to a 700r4 and aluminum drive shaft. 4 wheel disk brakes and rear end built with QA1 coilovers front and back next on the list. Still have the original 350 and tranny. They'll be cleaned up and painted original Olds colors and put on display in my shop whenever i get to that point in life. Blueprint 350.. PS/AC/Holley carb
It looks great. I can't argue with your decision- there's a point where you just want it to run well, and it seems like the old 350 would have given you constant trouble.
I wonder what it would take to get a remanufactured 394 for my 1964 Dynamic? You got me thinking about all the work ahead of me, and my realistic chances of success...
November 2nd, 2021, 07:47 PM
