´74 Olds Delta 88 straight out of hibernation, Q-jet´s fixed, now it´s wheels

I´m helping a friend of my dad´s bringing his barnfresh 74 Olds back to life and I have to admit, these late models are all different from what I´m used to wrench on. Maybe you guys can clue me in where I´m lost. So the story is, my Dad´s friend bought a property from an old lady whose husband had passed away in 2006. His old car was still parked in the garage and had not been started since. She wasn´t able to sell the car, so my Dad´s friend offered to buy it with the property. It´s an 74 Olds Delta 88, 350/ TH400 , that car was assembled in Switzerland and looks like it´s been taken care of quite well. Thing is, it wouldn´t start or run. All vacuum lines were brittle, the carb had severe vacuum leaks, points were burnt, condenser shot, I replaced everything from points to wires, rebuilt the carb, the cars starts right up and the choke opens perfectly, but the cars start to run rougher after a short drive and won´t start again when hot ( or hardly start again). Points , spark plug wires, cap, rotor, are new, carbs rebuilt and squirts perfectly, but it just won´t restart hot. I also tested the EGR valve, in it does open when I apply vacuum, but the intake manifold feels very hot. I have no idea if that´s supposed to be so or not, but I can see vapor coming up the venturis when I hit the accelerator pump.
So I guess my question is, is there something that can clog up or overheat the manifold? Any common mistakes I´m making? Ignition is timed at 12° at 1200rpm with vacuum canister disco´d, gap is set at .019". Plugs gapped at .035". Coil is new aswell... I´m runnig out of ideas , so anything that´s crossing your brains: please share it with me.
Thanks in advance!

 

Here´s what I´m working with
The carb had serveral servere vacuum leaks. Now it really runs well, but just won´t restart once it´s hot.

 

Heat riser valve stuck shut?

Flaky new condenser?

Did you take that fuel inlet fitting out of the front of the carb, and replace the filter that's in it?

 

You said it getting fuel when hot, but Did you check for spark when it’s hot? Some of the aftermarket parts these days are junk, and not necessarily good just because they’re new.

When I was in high school and got my license, my mom had a ‘73 Delta 88 with the 350. I pretty much inherited that till I bought my ‘66 GTO. Not an exciting car, but it sure was comfortable!

 

You didn't mention anything about the coil. Was it replaced?

 

Yes, the coil has indeed been replaced, along with the points and the condenser, but as Jim and Drake already stated, that condenser may be bad out of the box. I‘ll will change them out and see what happens, starting with the condenser. The egr valve on the driver‘s side of the Manifold does move if vaccum is applied, but I don‘t know if any internals may be plugged or stuck. What is a good way to check that? I did notice that the heat crossover is getting very hot, to the point I‘d say it‘s getting way hotter than on a typical GM car up to the mid 60s, but my other cars all do not have EGR. I‘ve also noticed the muffler is blown up and there‘s a bad exhaust manifold leak on the pass side head. Could a collapsed and partly clogged muffler build enough backpressure to overheat the intake manifold?
Thank you so much for your ideas, guys!

 

Do you know what a heat riser valve is? it's a device on one exhaust manifold that restricts the exhaust flow, making it go through the intake manifold to the other side, while the engine is cold. If this valve is not opening, it might be causing problems.

 

Does the choke gradually open as the engine warms up?

 

Yes olds intakes get very hot. They have exhaust gasses running through them. Your blown up muffler gives me a clue though that some critter may have gotten in there and made a home plugging things up. Also do like squirrel said and check the heat riser valve on the end of the exhaust manifold.

 

Jim, I did check for a valve on either side of the exhaust manifold , but there´s none, so I was thinking you meant the EGR valve up on the intake. Maybe I need to check again, but last time I was under the car I didn´t see a heat riser valve.

Yes it does now, since I rebuilt the Quadrajet. I starts right up and runs perfectly on coldstarts,and the choke fully opens. It´s a quite a low mile car and the carb´s not been messed with before , it was just old and had dried out gaskets.

I´ll try the following when I´m coming home from work tonight:
1. Look for the heat riser valve again and make sure it opens
2. Change the condensor
3. Poke into the muffler to see if it´s plugged...

Now that we are talking about it, I noticed it has pretty good torque at lower speed but falls on it´s face if I stomp it at lets say 60 mph. I hear the secondaries open and the transmission kicks down, but it hardly builds any power.....
Thanks, these are all great ideas!
I´ll keep you updated

 

If you have a dwell meter I would hook it up and check the point setting , 30 degrees is where I set them. This has nothing to do with your no start problem but is relative to a Olds motor with a egr valve. As you have seen the intake is super hot in the middle. The center push rods over time will get the oil cooked in them and become plugged no longer oiling the rockers. The rockers are held down by an aluminum bridge ( 1 bridge for 2 rockers ) the bridge gets chewed up from not getting oil and you will have rocker arm/lifter noise. It is a easy fix as there is no adjustment , just change the needed parts and tighten the bridge down. Just a thought for future reference. And that is a nice looking Olds !

 

Make sure the carbon button in the center of the cap is in good shape and the metal on the rotor button is rust free. The cap looks to have some age on it in the photo.

 

Odd , you say it has points. Any GM '74 and later I've owned had electronic ignition. Could be a euro thing?

 

HEI was first used in 1975 on most GM vehicles. A few got it earlier.

 

here‘s a short update cause I suck at typing on the phone . Plugs are looking great, spark is good, muffler is not plugged, but I could not find a heat riser valve either. There seems to be a boss where the exhaust manifold could have been drilled for one, but it‘s not , and no rod or nor spring are sticking out, so I´d say, it does nor have a heat riser valve.

 

Tonight it started right up and ran flawlessly , I drove it again until it was hot, no start again. Checked for fuel and spark , both were there. After a while I pumped the bejeesus out of the accelerator pump until I thought I must have flooded the engine badly. But it just coughed and started. Float Level is on spot . I feel like the fuel is evaporating from the hot manifold …

 

You can actually tell where exactly the manifold is getting really hot, as the paint is pretty much burnt up . This is the driver´s side manifold that has the heat riser boss cast to it, but I can´t find where the rod and spring would be.

 

the muffler looks suspicious, eh?

I agree it looks like no heat riser valve.

 

dwell is set at 30°. Thanks a lot for the heads up concerning the rocker issue. I´ll check into this once I get it running and restarting properly. My dad´s friend Rudi, who is eager to cruise this thing , wants it to be dead reliable. So that´s some very valuable information.

I was also surprised as I would have expected to see a HEI unit under the hood. But the car looks pretty unmolested, I think the distributor is the original one

 

Jim, yes it does. I removed it and poked a piece of hose through it, and there´s no "pluggation" going on as far as I can tell. It may even be pretty new. Rudi told me I wasn´t the first guy trying to get it running right, maybe someone before me flooded the engine and exhaust system and once the enginge hit , the muffler went BOOOOOM. It´s a pretty solid piece, not like today´s chinese made tin foil mufflers. There were a lot of Mockey Mouse fixes to get the car running, as carb base smeared down with bathroom silicone in an attempt to fix vacuum leaks and many more.

 

I'm highly suspicious of a plugged muffler. It looks-and acts...well, like it sure could be. And a '74 Olds with points is normal. Have a helper stand behind the car while you floor the throttle. It should blast his hand HARD. If not, it's restricted.

 

Here in the states, after 73 got cat converters between the manifolds and the muffler. They can plug up also and would make the car run worse the longer it runs. After they sit, they do OK until they run so long again.

The hot spot on the intake is because there is an exhaust passage that runs through the intake, The hot exhaust is what is burning the paint off the intake. The EGR valve allows exhaust from that passage to pass into the intake when the EGR valve opens. Its not uncommon for those valves to go bad and allow the exhaust into the intake when its not suppose to be there. The EGR valve can also cause an intermittent vacuum leak.

I believe I would just replace all the rubber hoses in the fuel line, from the tank to the carburetor. Have you checked the fuel pump pressure and the fuel volume it delivers? Could be a fuel line or pump issue as well.

The rocker arm issue is a real problem with the 350 Olds motors of that era. If there is any lifter noise in the motor, pull the covers and check the rockers and rocker stands. My aunt had several Oldsmobiles of that time frame. Every one of them ate the rockers and rocker stands (I had to change the stands every time I had to change the rockers, and it was usually 2-3 pairs of rockers & stands at a wack. They 350 Olds motors didn't do well with long time frame oil changes. I started replacing the rockers on her cars before they reached 50,000 miles. She insisted a 4,000 mile oil change was enough, and didn't car how long it took to get to that 4,000 mile oil change. The defective rockers (and stands) was not allowing the valves to open far enough, and her performance dropped off pretty bad when the lifters started to rattle.

 

After 1974....right?

 

Try pulling vacuum hose to EGR and plugging it.
Might rule that out anyway.
I had a similar problem with my later model 350Olds. They use a stamped metal intake manifold.
After sitting for years it somehow lost its seal and would leak when hot.
When you get it warmed up good and still running take a small spray bottle or squirt bottle of water and wet down the intake to head area. Listen and watch.
Mine ran a bit better and also was able to see the water being sucked in.
Those intakes are not light. Will take 3 men and a boy to swap. Especially that far into the engine bay.

 

In my mind if pumping the accelerator gets it to start either it’s set up very lean or there’s no fuel in the idle circuit.

Does it not start straight after tiring it off or is it that it doesn’t start 10 mins after turing it off?

 

The steel intake gasket does tend to corrode away over the years. Usually just makes it leak coolant, but you could look if you want to do some more work.

 

Just a couple of thoughts: obviously what you have is fuel getting too hot and percolating in the carb/fuel pipe. From what I see in the pics, the carb sits more or less directly on the manifold. Might be worth it to get a 1"-1.5" phenol insulation plate between the manifold and the carb. You can also get an insulation sleeve (Ärmel) to fit on the pipe from fuel pump to carb. Secondly I'd take the muffler off and run it like that to see what happens (yes I know, it's Germany but if you're living hinter 7 Bergen people will probably give you some slack). Last but not least, there's a way to plug this stupid exhaust gas transfer port. Unless I'm totally wrong this device is supposed to help running in winter and is utterly useless in summer (and we're having a 30°c plus summer now). I doubt it's relevant for any emission test (if you have them for the TÜV for Oldtimers. Us in Austria have them for our §57 inspection but that's MY problem lol). Edited to add: See below a link to how it's done.

Parts are indeed a pain these days, yes. I just got a set of new plugs, wires, points and condenser and hope they're good...

 

Taking some readings with a vacuum gauge may help. Brittle vacuum lines indicate a possible leak. Does it idle rough?

 

Beginning with the 73 model year. I worked at a gas station then and our station was the 1st in town with the unleaded fuel.