Mach 1 Club

Arggh [img]core/images/smilies/mad.png[/img]
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 [img]core/images/smilies/frown.png[/img] !! 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! [img]core/images/smilies/biggrin.png[/img]

Ok I'll take a stab at it. After setting so long, there is quite often a lot of sediment, crud, and varnish from old fuel in the gas tank. When you bring one back from the dead, it's not uncommon for the fresh fuel and "Sea Foam" to loosen all the crud in the tank, and it Immediately heads for the fuel filter, which plugs up almost instantly, especially if you have the filter that screws into the front of the carb. It's possible some of the crud got past the filter, and has plugged the Idle circuits in the carb, as noted by needing full choke to keep running. The main circuits are larger, and less prone to plugging. The 15 / 40 oil shouldn't be an issue. 

I think I would pull the filler neck out of the tank this can be done in the trunk. Take a "flashlight" No Open Flame! and a mirror, and look into the tank, and see how clean it is or isn't??? Pull the carb, and clean it. You may even need to sonic clean the carb, as I'm told this does an amazing job on carbs. Blow out all the fuel lines, and see if you get a bunch of crud? After everything is clean. I'd put a clear see through fuel filter in the line to the carb, you can buy a fitting at the parts store to replace the stock fuel filter. Then give it a go and see what you get.    Hope it helps. 


JTS

Thanks for the reply, really detailed, but, I've been thinking, and could I have put a can of diesel in........it was late and I was looking forward to getting home after a long day?

Good advice from JTS. Diesel could be the problem. You should be able to smell the difference from petrol and diesel at the gas filler. Good luck.

Yes, Diesel would definitely do what you are describing. I worked for A John Deere dealer with 2 Identical Chevy service trucks. One Gas, and One Diesel, and several times I had to drain the diesel out of the Gas one, and the gas out of the diesel one. We had our own fuel pumps, and both nozzles were the same size. We put a DIESEL sticker on the side of the diesel truck near the fuel door which helped. But it still happened occasionally. Sounds like you're on to something. Let us know how it goes. 

JTS

Yeah, what an ass I feel!!! Never done that before in 42 years of driving!! Feel free to ridicule me
Smelt and felt like diesel, so 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!

(05-02-2022, 09:30 PM)mach71 Wrote: [ -> ]Yeah, what an ass I feel!!! Never done that before in 42 years of driving!! Feel free to ridicule me
Smelt and felt like diesel, so 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!

Don't feel too bad, it happens. I did something similar to my boat. The gas filler and the fresh water filler screw-on caps look identical unless you look at the small symbol on the cap. Although they are on opposite sides of the boat, I absent mindedly added fuel stabilizer to the fresh water tank! Fortunately I realized it before I turned on the 4 different water faucets/showers and toilet on the boat and did a lot of flushing through the faucet near the tank.

Don't panic the diesel will not hurt a thing, in fact it will lube the top end of the engine, and clean the entire fuel system one end to the other. It will also clean all the carbon off the valves pistons etc. You have to get most of it out, and fill with fresh gas for it to run correctly again, but the little bit left over will be beneficial to the engine in the long run. I'd Drain what I can, fill with gas, change the fuel filter, and drive it. You'll probably find it runs better then it did before.    LOL!

Jack

PS we used to put a quart of diesel in the tank occasionally back in the old days especially if we had one that was carboned up real bad. So believe me it's all good. Except maybe you're bruised ego.