First things first. The DeLorean engine is meant to run on 87 octane rating fuel (US measuring method). Using higher rating gas is just a waste of money and actually does nothing good. 93 is not better than 87. It is different. Use 87 as it has more energy content. The higher the octane rating the less energy the fuel has.
Do not pull the spark plug wires off with the engine running. Apart from a risk of a serious electrical shock you risk flooding the catalytic converter with unburned fuel and actually flooding the cylinders. That in turn washes oil film off of cylinder walls. That mean no lubrication for the piston rings... and that is really bad.
If you need to find out which cylinder is misfiring you can use a spark analyzer or just stop the engine and remove the spark plugs. They tell you a lot about how that particular cylinder is operating.
To help you diagnose your problem we need to know if your frequency valve is working. Do you hear it buzzing? This thing is responsible for fuel pressure and fuel quantity injected.
If you do hear it running then I would recommend checking the cold start valve. Remove the two bolts holding it down and see if it's dripping. If it has been sitting for so long it's possible that this valve was able to open but then jammed and is flooding the engine. Make sure the fuel pump is running when checking the CSV. Do not start the engine.
Next test - with the engine off jump the RPM relay so the fuel pump is running. Go to the engine and depress the air metering plate slowly all the way down. There should be a fair amount of resistance but the plate should go down smoothly without binding or grinding. Then after releasing it should go back up fairly quickly. Do this a few times to make sure all moves smoothly. If you feel any grinding or if the metering plate doesn't come back up quickly then you might have a gummed up fuel distributor.
If everything checks out ok then the most probable cause is the CPR also referred to as the warm-up regulator. It lives on the left valve cover. They do go bad and when they do, they mess up the fuel pressure and fuel delivery.
Let us know what you find and we'll go from there.
Greetings from Poland!
Vin 6149 plus 2418, 3633, 5030, 16473, 17086
Google earth: 52°25'17.66"N, 21° 1'58.40"E
Okay, got one that has me stumped. First, some history.
This car has not run in 8+ years. It was stored inside with ethanol gas in the tank--first big mistake. I pulled the fuel pump, drained the tank, and cleaned the entire inside. I installed a new fuel pump with the John Harvey pickup and return (no more rubber hoses to deterioate). Next I flushed the entire system from the fuel pump to the mixture control using 93 octane gas. I pulled the plugs, cleaned and tested 4.0. I pulled the fuel injectors, cleaned and tested. Good 35 degree spray pattern on all six. I purchased a new battery and was ready to big test.
After several trys, engine caught and ran at ran rough at 2000 rpm. It wouldn't idle and I shut it down after about 10 seconds to check for any leaks. All checked out dry so I tried to start again. Would not start, although it was always right at the verge of starting. I pulled the plugs and injectors and recleaned them. Put it all back together and tried again. Started again, but I had to keep the rpm above 2000 or it would try to die. Had tons of white smoke coming out the exhaust, but that cleared after about 15 seconds. After about 15 more seconds, I shut it down again to check things. Again everything looked good, so another try at restart. No matter what I did could I get it to start and every try produced a strong fuel smell at the exhaust pipes, so I slept on it last night.
This morning, I tried again. After cranking for about 5 seconds, it started but wouldn't run at less that 2000 rpm and had black smoke coming out the exhaust. Let it run for about 10 minutes this time to warm everything up. Car appeared to be missing the whole time. Started pulling plug wires to see if I could isolate misfiring cylinder(s). Pulled #3 first (firing), then #2 (firing), and then #1 (firing) but didn't get it back on quick enough and engine stalled. Would not restart. Pulled all six plugs and all six covered with black soot, indicating very over rich condition.
I know this has been long, but my question is "where do I go from here"? The car won't idle, it appears to be running super rich, and it won't start a second time after running for any period of time.
Mike TPS 1630
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