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I thought the engine was simply dieing out of the blue. Are you saying that a warm engine (just before otterstat opening) idles OK, but dies when you open the throttle plates? If so, that just sounds like your choke plate isn't opening.Quote:
Originally Posted by Farrar
Bill Robertson
#5939
Cold engine idles fine. You can punch the gas and it revs up and settles down into idle fine.
As engine warms up (approaching the first line on the temp gauge), it starts stumbling and the idle speed drops lower and lower. Try to compensate by giving it gas, and the engine quits and will not re-start until the engine is cold again.
Farrar
This sounds like a choke plate that isn't opening.Quote:
Originally Posted by Farrar
This doesn't sound like a choke plate problem.Quote:
Originally Posted by Farrar
Did you pop the top off the carb to look inside? You have to be careful not to put the tab that connects the choke plate to the activation lever on backwards when the choke spring is fully expanded. It's real easy to do when putting a warm carb back together. If you put that tab on backwards, the engine won't even restart -- the choke plate will be in a totally closed bind.Quote:
Originally Posted by Farrar
Bill Robertson
#5939
Look at your choke plate.Quote:
Originally Posted by Farrar
You just did a bunch of wiring work in your engine compartment -- make sure you didn't disable the 12v line to your choke spring.
Bill Robertson
#5939
I couldn't post here for a few minutes. Blame the Internet.
Bill, I checked the choke heater when the engine died -- it was hot, so it has voltage. The choke plate was wide open when the engine died.
New development: starter will engage from the engine compartment, but not from the key, after engine has died.
Electrical issue?
Farrar
As the pork chops sizzle in their pan, I have a quick question to ask:
Could it be a bad impulse coil in the distributor? How would I check that?
Farrar
Here's what I did today.
I bypassed the fuel pump (or "RPM" in DeLorean terms) relay by bridging switched power to the fuel pump. The fuel pump is now energized when the key is in ON and START.
I took advantage of the now-only-partially-used RPM Relay Socket for a source of unswitched, fuse-protected power to the cooling fan temperature switch (or "otterstat" in DeLorean terms), so that my cooling fans will now run after the engine has switched off, until the temperature drops below 195°F and the otterstat breaks the connection to the cooling fan relay.
I removed the air cleaner housing so that I could observe the action of the choke plate.
I checked the PCV valve: it rattles when shaken.
Having now eliminated the RPM Relay from the potential causes of what I have the urge to call Sudden Engine Death Syndrome but probably shouldn't owing to those of a sensitive nature, I checked the fluids, double-checked my recently-made electrical connections (including inserting a jumper to make the cooling fans run), and started the engine.
It started on the first turn of the key without hesitation.
The choke plates moved as they should -- opening just a touch when I started the engine, and then within a couple of minutes of idling becoming wide open.
After the choke plates had opened, I pressed the throttle to disengage the fast-idle cam, then released the throttle.
The engine settled into its prescribed idle speed of 950 RPM and idled beautifully.
The voltmeter read approximately 13.5 to 13.8 volts.
As the temperature gauge neared the first line from the bottom, the engine started to burble, but the idle remained at about 950 RPM.
Slowly, the burble became a stumble.
I was standing back by the engine as this was happening, seeing if I could observe any changes. I saw nothing. Suddenly, the idle dropped -- it sounded to me like it went down to 700 or 650 RPM. By the time I had walked forward and stuck my head inside the car to look at the gauges, the engine had quit running. It will not start again right now.
Next?
Farrar
Just because I thought it might be diagnostically useful, this time I took a video. When I observed the end of it, I heard the fuel pump NOT SPINNING. So I opened up the carburetor bowl and saw a tiny bit of fuel. When I hooked up the fuel pump again, it ran for a second and then died.
I am sick of these damned Made In Mexico fuel pumps. Someone please make me a recommendation for another low pressure fuel pump with a 1/8" NPT fitting on the end.
Farrar
Apologies for the delayed response -- I have been driving my crappy carbureted DeLorean to DC (via Virginia Beach -- spent last night at the sleaziest motel in Norfolk, yet none of my windows were broken this morning!).
Autozone now sells Made in China pumps under the same part number (E8012S). They will fit inside your carrier (they are smaller than the Airtex units), but the top barb is built-in 5/16".
I put a Mr Gasket (Prestolite) pump on one of my church's school buses. It only puts out 3-4 PSI. I had to augment it with an Airtex pump by the tank, for a total of 12 PSI.
Advance still sells Airtex pumps.
A mechanical pump wouldn't really be any better -- gasohol causes the diaphragm to split.
See now why farmers strap a tank to the roof and just gravity feed the carb....
Bill Robertson
#5939
It's all right, Bill -- it's too hot outside for me to do much of anything, anyway.
At least this fuel pump failed in a creative way. The last one simply had me driving down the road and then poof -- the engine died. No chance of re-starting that one. This one was stealthy. In fact, I bet if I went outside right now and tried it, it would run for another five minutes and then quit.
AutoZone's Made In China fuel pumps don't give me much confidence if they're meant to replace the Made In Mexico units that fail after one year's occasional service.
There's an O'Reilly near to me which stocks Airtex E8090 fuel pumps. That unit is a 12V, 5-9 PSI, 30 GPH pump that comes without pickup screen but otherwise looks the same as the Airtex units I have been burning through every summer. Its retail price is $63.99. "Contact store for warranty details." Oh, boy. Perhaps I should buy a more expensive failure-prone unit. At least it will fit inside the fuel pump carrier, or so it appears from the photo.
http://images.oreillyauto.com/parts/...ix/e8090-1.jpg
Or...
Also in stock is a Mr. Gasket 12S fuel pump. That's a 12V, 4-7 PSI, 35 GPH unit which is listed as "micro electric" and I am pretty sure will not fit inside the Bill Robertson Fuel Pump Carrier®. Retail price: $44.99. "90-day limited warranty."
http://images.oreillyauto.com/parts/...um/mrg/12s.jpg
I guess if I used the Mr. Gasket 12S, I would have to mount it somewhere outside the fuel pump carrier/boot and run a hose from the bottom of the fuel pump carrier (read: from the pickup screen) to the fuel pump, wherever it happens to be. Question is, where? I don't want to drill holes in the fuel tank for the pump mounting brackets, and I don't want to run a long hose subjecting myself to vapor lock, or having to install a check valve of some sort -- another part to fail down the road.
Although -- I wonder if "micro electric" would be more reliable than the "solenoid" units I have been using. Thoughts?
Farrar
As stated, my church's school bus is using both a Mr Gasket (made by Prestolite) pump under the hood, and an Airtex pump next to the tank. The Mr Gasket unit produces very little fuel pressure.
Bill Robertson
#5939
So yours is also a 12S? Hmm. I was hoping it would produce 5 PSI which I think would keep the 2100 happy.Quote:
Originally Posted by content22207
Well, I suppose it's off to O'Reilly for an Airtex E8090.
(AutoZone does not sell this unit -- they sell an E8887 which is 10-14 PSI, and everything else is either too low fuel pressure or too high fuel pressure for my carburetor.)
If the Airtex E8090 works, and fits, I guess I will buy a spare and keep it in the car with me along with my jumpers, fuses, belts, and relays!
Farrar
Sequence of events Re school bus:
1) Started suffering what may be fuel delivery issues (I was not driving the bus -- just getting negative reports second hand, which had to be filtered through the prism that no one likes this particular bus -- complaints could have been mere griping from a driver who also drives like a Bat out of Hell, which this bus simply never will do by original design)
2) Installed a dash mounted fuel pressure gauge, which was a total waste of my time because the above mentioned driver doesn't monitor dash gauges -- hence the other dead school bus she did eventually manage to kill.
3) School bus dies on the side of the road, I restart it and drive it gently back to the church, but fuel pressure isn't even reading on the gauge. Suspecting a failing mechanical pump, I installed the Mr. Gasket unit, which does produce 4 PSI when the needle valve is closed, but drops to zero when the engine is running wide open (renders the fuel pressure gauge useless, but as stated above that doesn't really matter when the Steering Wheel Wiggler, AKA bus driver, doesn't even bother to glance at the damn thing).
4) Bus dies again on the side of the road, this time going uphill. I restart it again and barely limp it over the hill, at which time fuel pressure comes back. I begin to suspect a problem pulling from the tank, confirmed when I floor the bus and it runs wide open and dies shortly thereafter, at which time I pull the the top off the carb and find the bowl dry, yet the pump makes normal noises and refills it sitting still. I gently drive the bus back to the church, install a pickup from the bottom of the tank, and the second fuel pump.
I have since successfully driven the bus myself to/from Fayetteville at 55 MPH and Maxton at 60 MPH (the poor thing screams on the highway -- it's got a big Allison automatic that shifts into 3rd gear around 25 MPH). With both pumps running, fuel pressure reads 12 PSI at idle, dropping to 4-6 PSI at full throttle.
Negotiations are under way to fire the Bus Killer and hire me to drive the buses.
Bill Robertson
#5939