AAZ quit on Gas

[95gltd]

I tell ya things couldn't have gone worse this week, first a death in the family now this.

Mother in law came down to visit and has been driving my 95 AAZ golf. It was down into the red on the guage and she put 15L of regular gas in it. She drove it for about 2-3 km before it finally quit.

On top of it all the injectors were rebuilt along with a pump rebuild from Tin Tin maybe 25,000 km ago.


I was going to try and hook the pump directly to a can of diesel and purge it and then try and start it on the diesel in a can last night. By the time the tow truck came and all it was too late.

The pump is lubed by the diesel fuel, so I'm assuming the pump is fried ?

[53 willys]

you will be fine....drain the tank...change the filter...fill with diesel...and crank her until she starts..
I highly doubt you did any damage.....if you got a gas car at home pump the fuel into it...wont hurt it one bit.
dont ask how I know

[95gltd]

Well thats good to hear.

I'll order up a new filter today and tonight I'll purge the pump, blow the fuel lines out, drain the tank.

I was just thankfull that she didn't have my 12V cummins and gassed it up. I already had the pump in and out of the VW, so worse case scenerio I knew how to go about it.

[87octane]

Can someone give a newbee the quick walk through of what happens in the combustion process during the compression/injection/combustion event that makes gasoline physically damage the diesel head/pistons/rings/bearings/other components?

[53 willys]

Can someone give a newbee the quick walk through of what happens in the combustion process during the compression/injection/combustion event that makes gasoline physically damage the diesel head/pistons/rings/bearings/other components?

Ive never seen or heard of any real physical damage caused from gasoline in a diesel...

[truckinwagen]

long term(if you could get it to run on gas long term) the pump could see wear, as it is lubricated by the fuel and gas is not a lubricant.

[53 willys]

basically gasoline has to low of a flash point to compress enough to lite off in a diesel engine......=cars dies after diesel is purged from fuel lines and straight gas is tried to compress then ignite...drain the tank, refill with diesel, change filter, bleed the system, and you should be good to go

[95gltd]

Thanks again 53 Willys

I have one other question. I've never seen a lift pump on the VW. Does the IP suck the fuel all the way from the tank ?

Reason I ask as my old powerstroke DI had a lift pump and my 12v dodge has a mechanical lift pump too.

I realize they are different beats from the bigger diesels. The 12v p pump cummins engines the bottom half of the pump is lubed by engine oil so running out of feul or pressure isn't so bad. The newer 24v pumps if they so much as lose pressure will fry the pump. This got me thinking the gas in the VW pump would kill it.

[8v-of-fury]

Can someone give a newbee the quick walk through of what happens in the combustion process during the compression/injection/combustion event that makes gasoline physically damage the diesel head/pistons/rings/bearings/other components?

Absolutely Kind Sir,

Running gasoline doesn't really hurt anything but the Injection Pump(IP). I've heard a lot of old timers running as much as %25 gasoline in there tanks to prevent gelling of the Diesel fuel in colder climates, now on these old IDI's that's ok but i don't think you'd want to try that with a newer TDI. The reason Gasoline is bad for the IP is because gasoline has virtually ZERO lubricants (neither does new ULSD.. but we won't get in to that right now) and does not sufficiently lubricate the pump components.

Also a good thing to note is that Diesel and Gasoline ignite at very different Temperatures and Pressures. Have you ever noticed how badly a diesel runs when it has low compression? That is because the Diesel fuel needs that compression in order to ignite. Diesel engines typically run in the 450-500 psi range.. where as it is not uncommon to find Gas engines running around on as low as 100psi (a very very very worn engine). So you can see that when the gasoline that was meant to ignite around 150-180psi is injected in to a very high pressure cylinder it ignites at the improper time.. Not really causing any damage, just grief and poor running of the engine.

basically gasoline has to low of a flash point to compress enough to lite off in a diesel engine......=cars dies after diesel is purged from fuel lines and straight gas is tried to compress then ignite...drain the tank, refill with diesel, change filter, bleed the system, and you should be good to go

The 12v p pump cummins engines the bottom half of the pump is lubed by engine oil so running out of feul or pressure isn't so bad. The newer 24v pumps if they so much as lose pressure will fry the pump. This got me thinking the gas in the VW pump would kill it.

Word of the wise to the OP, Not only do I not lend my car to anyone, i would NEVER lend it to my mother-in-law... lol Lesson Learned the hard way I guess. lol The car should be just fine Gasoline WILL kill the pump if you were able to run the engine that long on pure gasoline.. other than that.. 2-5 kms of driving.. no way. These things were designed to survive a friggan war lol

[burn_your_money]

VW diesels don't have lift pumps (until you get to the newest TDIs). The injection pump on the engine is capable of pulling fuel from the tank.

Diesel is high in cetane and low in octane, gas is high in octane and low in cetane. They are at opposite ends of the scale which is why your car won'r run on gasoline.

[95gltd]

Got her back on the road last night.

After getting all the gas out of the pump and full of diesel, filled the new filter with diesel and once the tank was drained and refilled i pressurized the tank with an air gun and blew the gas out of the lines untill diesel came out. Got in 1 turn of the starter and it fired up and didn't miss a beat.

Thanks for all the help.

[arb]

Got her back on the road last night.

After getting all the gas out of the pump and full of diesel, filled the new filter with diesel and once the tank was drained and refilled i pressurized the tank with an air gun and blew the gas out of the lines untill diesel came out. Got in 1 turn of the starter and it fired up and didn't miss a beat.

Thanks for all the help.

Great news !!  I hope your mother-in-law took you out for a nice dinner as an apology ;-)  My mother-in-law does not drive so I don't have to worry about that.

[catlin_cava]

I don't think mine can drive standard...

[95gltd]

She took care of the bill which was pretty decent compared to what i anticipated.

$60 towing
$55 filter

Could have got the filter online for $22, but was in a pinch and on her dime

She's from Europe where almost everything is standard.

[catlin_cava]

$55 filter

55$?? I paid 14,75$ for my filter in an Auto Parts Store....