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mach1dave

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1971 Mach 1
Arggh
Mad :mad:

After getting the mach1 back on the road after sitting for a good few years, with the occasional start up, every thing was good, running well, idling good, good vacuum. Drove last Saturday to Mill Hill, then on to Borehamwood, then home, no problems. Put £25 petrol in on way home, Sunday morning, tank was empty!! Anyway, saw it was dripping from petrol pump, so ordered a new pump and knowing the oil could be contaminated with fuel new oil and filter. Pump fitted yesterday along with oil/filter change and a can of fresh petrol. Go to take it to the petrol station today to fill up, start it up and I got smoke billowing out of the exhausts
Frown :frown:
!! And I mean billowing!! Also running very rough, kept cutting out, only managed to keep it running with full choke, which it rarely needs usually. Also a mighty backfire at one point! Only difference is I went from using the Valvoline VR1 20w-50 oil to a cheaper 15w-40 oil, and the new Carter fuel pump? What the f*** has happened! Smoke colour is dark, but not black, but not bluey grey either! Doesn't smell too petrolly either. Used some sea foam a few weeks ago, seemed to run slightly better afterwards, so this is purely a problem since the fuel pump/oil change yesterday.
Could the slightly thinner oil be getting in somewhere it shouldn't?
I'm guessing while the petrol pump was leaking, it was not delivering full pressure, so now it is could it be flooding the carb?
Any advice on where to start will be greatly appreciated!
Biggrin :biggrin:
 
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1971 Mustang Mach 1, M code, 4 speed.
This is just my logic thinking here.
First, when you put the new pump in, you made sure the pump arm was under the eccentric cam. I'm sure you did though.
The oil wouldn't be the issue unless something else has given out coincidently at the same time as the pump failing. Talking of oil, I use Castrol 10W30 in my Mach 1.
As Doug says above, it could be too much fuel at the carb floats now the pump has been replaced. With my limited knowledge, I think the carb is most likely the issue now.
Next question, what carb is on your car. Has it been rebuilt lately and since it has sat for a long time, it may need to be done.
Check your plugs for wetness or oil.
The list goes on, but I'd start there. Good luck.
 
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Phoenix
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'73 mustang convt.
My typical first advice when a car starts having issues it mess with the carb last. But in your case I think it's the carb. When replacing a petrol pump it's a good idea to check the float levels. Also, after sitting for so long, even with the occasional startup, the rubber parts of the carb may also have dried up. Mine did. My accelerator pump was hard as a rock and the power valve was leaking.
 
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71 Sportsroof Bright Red.

Pull a couple of plugs and see what they look like. If carboned up, then fuel problem and most likely the floats are off in the carb due to new pump. If oil fouled, then you got either valve seals or ring problems. Also check radiator to see if it's low. May be a head gasket or intake manifold gasket leak. As mentioned above I would also rebuild the carb if it hasn't been done. Ethanol eats the heck out of the older rubbers and seals causing leaks and failures.
 

mach1dave

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Guys, thanks for the replies, but, is it possible I put a can of diesel in..........it was late and I was thinking of getting home after a long day?
 

machattack

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1971 mustang mach 1 351c 4v auto fmx
1968 mustang gt 302 4v 4 speed
Guys, thanks for the replies, but, is it possible I put a can of diesel in..........it was late and I was thinking of getting home after a long day?
Ahhh Man, that would be awful. But it wont really hurt the engine. Drain it out. start with new fuel.
Should be able to just smell the fuel and get that hint of diesel fuel smell. Or feel it to see if its got that oily texture. Most certainly would burn weirdly with grey to black smoke.
I would vote on the side of carb issue, however need to rule out the diesel fuel thought.
 
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73 Grande will undergo three phase build process. Phase 1 is to make roadworthy. Phase 2 is interior/exterior restoration. Phase 3 is ++ performance.
Maybe an off the wall idea; you did say you ran the tank to empty, and it’s been sitting for a long time. Is it possible you’ve pushed a bunch of junk into the carb?
 

mach1dave

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Thanks guys, but pretty convinced now I put diesel in. Smells/feels like diesel.
Just spent the morning draining as much of the system as possible, luckily I had only put 5 litres in, and it still had a little petrol in as well. Will use some sea foam when I refill, hopefully it will help clean the remaining diesel out!
(Fitted new tank 60 miles ago)
 

skerwath

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Texas
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1971 Mach 1 351C 2V
I had a similar situation when I switched from 2bbl to a 4bbl on mine. I messed with it figured I was way smarter the the repair guy that wanted too much to fix my car. Once again, my pride pokes me with the semi-truck in the butt. Cost me some money, but the shop put a smaller cfm carb on my car and a spacer. Runs like a champ now, and I stopped pissing unburnt fuel out the tail pipe on the exhaust stroke. Sound like you are running too rich. Black and blue smoke is oil. Grey and white is inefficient combustion. Just be glad it’s not coolant or you’d be looking for a new block.
 
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My all time favorite vehicle is our 1969 Shelby GT500
I know for a fact that adding diesel fuel to gasoline will cause it to put out a lot of smoke. It will not do any harm to your engine when diluted with enough gasoline. In order to make certain it is being kept as dilute as possible, when the tank is half empty I would refill it. Then drive it enough to get it down to about 1/8 full, or lower if you dare (lower is better). Then fill it up with non-ethanol gasoline.

As for the fuel pump, our 73 Mustang convertible's 302 2v engine had a fuel pump that began to leak externally also. But I also checked the engine il, and smelled gasoline in it. Often when the fuel pump diaphragm begins to leak it will send gasoline into the crankcase also, which will contaminate and thin out the oil. The oil's ability to protect the internal lubricated parts is compromised. In your case adding diesel fuel to the gasoline may have helped prevent a disaster as diesel fuel provides ome degree of lubricating protection.

In any event, I suggest you pull the engine oil dipstick and smell the oil. If you get any indication that there may be a gasoline smell change the oil and filter. Better safe than sorry. And speaking of engine il... If you are still running with a flat tappet cam and lifters (if it is an original engine, or a rebuilt with original style flat tappet lifters and cam, you need to use an engine oil wth Zinc in it to protect the valve train from excessive wear. Zinc will cause the catalytic converters in newer cars to foul, so many oils on the market no longer have Zinc. You will either need to use a Zinc additive, or use only engine oil with Zinc in it. I use AmsOil Z-Rod 10/30 in our engines. There are quite a few oil brands with blends that include Zinc. If it has Zinc in it the label will state so. Without Zinc your cam and lifters will get wiped out very quickly. If the cheaper engine oil you had used lately does not have Zinc in it I suggest you replace it quickly, and to not drive until you have oil with Zinc in it inside your engine.

Back to the diesel in the gasoline.... Long ago I had a service manager at a Buick store tell me they had a lot boy who would steal gasoline from the shop's fuel can for his personal car. Everybody knew he was doing it, and he kept on doing it anyway. One day the service manager filled the fuel can with diesel fuel. The lot boy stole it, and his engine began to smoke badly. He asked the service manager what he thought it may be. He told the kid it could be worn piston rings, but if he had accidentally used diesel fuel instead of gasoline it could do that also, and often the engine needs to be rebuilt afterward due to internal problems caused by burning diesel fuel in a gasoline engine. The kids began to rebuild his engine that following weekend.

Now, I do not condone lying to the kid about damage caused by diesel fuel being burned in a gasoline engine, but it was a funny story. I bet the kid never stole gasoline like that again!

Back to the smoking engine... If you have a Holley carburetor, or an Autolite 2100 or 2150 two barrel carburetor, they have a Power Valve that is prone to leak or rupture, which will cause black smoke from your engine due to excessive fuel consumption. If you keep getting black smoke after burning/using all the diesel fuel in your gas tank you may have that problem.
 
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1971 Mustang Mach 1 M code 351 4 speed
If you are sure you put diesel in it, then there is your problem. If not, what I have seen happen quite often is that when people change fuel pumps, fuel filters, and even when they put a new carburetor on the engine, when they are dealing with the inevitable rubber lines connecting to steel lines and pushing the rubber lines into the steel lines, sometimes a small piece of rubber will get sheared off into the fuel lines and will then travel into the carb, and lodge itself on the needle and seat. The needle and seat then cannot close and you end up with a very rich running condition. The rubber can also pass through the needle and seat and then lodge itself on a main jet, that will also cause a ton of drivability issues as one side of the carb is not getting enough fuel. To see if the needle and seat in your carb is not sealing, just pull the air cleaner off and look down the carburetor while the car is running at idle. If you can see gasoline dripping from the boosters inside the carburetor, your needle and seat is not sealing, probably because you have some dirt on it.
 

machphil

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Illinois
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'71 and '73 Mach 1's.
Arggh
Mad :mad:

After getting the mach1 back on the road after sitting for a good few years, with the occasional start up, every thing was good, running well, idling good, good vacuum. Drove last Saturday to Mill Hill, then on to Borehamwood, then home, no problems. Put £25 petrol in on way home, Sunday morning, tank was empty!! Anyway, saw it was dripping from petrol pump, so ordered a new pump and knowing the oil could be contaminated with fuel new oil and filter. Pump fitted yesterday along with oil/filter change and a can of fresh petrol. Go to take it to the petrol station today to fill up, start it up and I got smoke billowing out of the exhausts
Frown :frown:
!! And I mean billowing!! Also running very rough, kept cutting out, only managed to keep it running with full choke, which it rarely needs usually. Also a mighty backfire at one point! Only difference is I went from using the Valvoline VR1 20w-50 oil to a cheaper 15w-40 oil, and the new Carter fuel pump? What the f*** has happened! Smoke colour is dark, but not black, but not bluey grey either! Doesn't smell too petrolly either. Used some sea foam a few weeks ago, seemed to run slightly better afterwards, so this is purely a problem since the fuel pump/oil change yesterday.
Could the slightly thinner oil be getting in somewhere it shouldn't?
I'm guessing while the petrol pump was leaking, it was not delivering full pressure, so now it is could it be flooding the carb?
Any advice on where to start will be greatly appreciated!
Biggrin :biggrin:
I filled my '77 F150 with diesel once without realizing it and drove it home. I didn't get far. Maybe two blocks. The engine started rattling from detonation. It was a 351M so it was low compression and a two bbl. I siphoned it all out after getting home and refilled it with REAL gasoline. The engine survived. They put green nozzle covers on diesel now. I can't remember about back then as it was in '82 or '83.
 

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