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Engine Specific Info and Questions => IDI Engine => Topic started by: 8v-of-fury on May 24, 2011, 07:36:52 am
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And from an frequent member even!
Now, I consider myself to be above average on the knowledge of how and what these diesels need to run.. And I'm pretty sure my IP is on its way out..
Go outside today to do a final torque on my head bolts.. so i was gonna drive it around as they call for a warm torque. Get inside, fires up as normal, immediately begins to run rough (like 400rpm). does this for a couple seconds.. dies. hit the gp's again and attempt another try crank crank crank crank crank starts to run, then rough again but not for a couple seconds this time, immediately dies. crank crank crank crank with the peddle down, starts and revs up like normal for the first rev on the way down the rev it stalls out. Lots of smoke while this is happening also!
So I pop the hood, and look around. rig up some wiring to control the pump solenoid, starter, and glowplugs from the engine bay so i can diagnose.
solenoid is clicking fine
the glowplugs are fine
I pulled the lines off the filter and blew and sucked on both, and there doesn't seem to be any restrictions in either.. At this point I figure I have a plugged up fuel filter or something right, even though i haven't noticed any performance issues. pull it out, and while im at it i run the car off a jerry can of older diesel.. couple of weeks old (stuff in my tank is Friday, and I've already put 300km on it so thats not the problem), and what do you know.. it draws from the jerry can and takes off no problem. Starts up runs rough as it works the air out, and then perfectly normal.. revs up and everything.. So i figure HMM! Musta been the fuel filter since i could blow each line with no issues.. I just happen to have a spare full of diesel sitting in the garage. Put it in, starts up on the fuel still in the pump from jerry can, and then runs the exact same way as before.. #@$%.
I have had this problem before.. on an older pump that sat for years.. the shaft bushing went bad and it wouldn't pull from the tank, ran rough and had no idle. YET it would still rev up if you gave it peddle and held it. it had a pretty bad leak on the bushing yet still ran.. it was so bad it was flinging off the belt while running and it even had a hole in the clear fuel line from the filter to the pump! This engine has tight fittings everywhere.. and no visible leaks belt side of the pump.. yet wont run for more than a second..
This is quite the bummer! it was running perfectly fine up until now.. what a time for this to happen i'm set to drive to New Brunswick (4000km total trip) in this car next Tuesday...
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Another thing, on the start where i can get it to rev up i can physically see it trying to pull fuel up to the filter from the hard lines. Turning the starter over doesnt seem to pull fuel up from the tank though...
I have clear lines from hard line to filter, filter to pump, pump back to filter, and filter back to hard line. I see all!
ANY IDEAS!?
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fuel starvation could be caused by bad fuel lines, a cracked water separator, bad connection to the fuel tank, messed up sending unit. I'm guessing here, but I'd look at the fuel lines and water separator, then the sending unit. You can also test the vacuum on the pump by running an intake line into a jerry can, which if you weren't so frustrated would have done already. Double check your timing if you are getting fuel but no combustion. Take a deep breath and relax you'll fix it quickly.
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The breathe has been taken.
No water separator, fuel lines seem fine in the engine bay, they are metal hard lines back to near the tank where small rubber ones go on to the tank. The one from tank to feed line is new, installed that when i swapped this car to diesel in Jan. Its an mk1 btw ;). what could go wrong on the sending unit? telling me i gots fuel when i really don't? Hmm it says 1/4 tank ive got about 275 out of the $20 i put in at $1.20/L all highway.. so assuming I pumped in 24L, and it wasn't empty I should have somewhere around 11-12L or 1/4 tank like the guage says.. Me thinks it checks out, for a rough test.
ALSO I did the "run it from a jerry can" test, fired right up and ran perfectly fine. Combustion and timing are spot on, It ran flawlessly (as if there were no problems) off the jerry can.
Injection Pump Is D.O.A isn't it :(
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Another thing, on the start where i can get it to rev up i can physically see it trying to pull fuel up to the filter from the hard lines. Turning the starter over doesnt seem to pull fuel up from the tank though...
I have clear lines from hard line to filter, filter to pump, pump back to filter, and filter back to hard line. I see all!
ANY IDEAS!?
Can the pump draw fuel from a jerry can thats on the floor? Pull fuel up the same head as from the tank?
If it can/can't then that should say something about the condition of the pump and your fuel lines?
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if you are running an IDI and it fires from the jerry can, it means everything from the pump to the tank should be suspect. The pump works if it pulls fuel from the can. The filter could be crap, the fuel lines could be compromised with air leaks, the sending unit could be partially plugged with floating debris. Like I said, start cheap, replace the filter, then the soft lines, then the sending unit to check for debris floating in the fuel. I've seen guys put a kim towel in company trucks fuel tanks to cause "ghost" problems.
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If this is a Mk. I fuel filter set-up, change the copper washers at the top where the fuel line enters/exits.
Also the washers on the pump banjo. Better yet, buy some of the Zexel brand rubberized washers and employ those instead.
I was so happy the day I sold my last mk. I....never looked back.
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Yes she be a 91 ME N/A hydro motor in a 84. I currently have a mk3 filter setup with the fuel running to and from the filter on each trip. No leaks there.
I guess I gotta pull the backseat and look down in the tank...
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put a lift pump in upstream, and wait for a leak to show.
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check your fuel lines and filters for pine needles, they have a way of causing headaches on VWs..
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Could you have an issue back at the fuel filler cap area? EG blocked cap vent, blocked crudded up fuel vent etc.... All would disappear from a Jerry can ???
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Perhaps than use Jerry can try only one original line and another one to jerry
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Because this car was gasoline not to long ago it doesn't have a venting gas cap, it has a third line that follows the hardlines back to the tank that I have snipped off in the engine bay. Pine needles? How does one get pine needles in on ones gas tank? Lol kev I think you had vandles! Ill pull the back seat and check the sender and look in the tank.. Can you physically see the fuel in the tank by looking through the tanks top on an mk1 jetta?
Also what I was thinking is a small helper pump with a low psi of 3-5 inline would work great.. So like any fuel pump for a carb application should work out fine for me eh? If it is ok to pump gas.. Can it pump diesel too??
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Can you physically see the fuel in the tank by looking through the tanks top on an mk1 jetta?
Also what I was thinking is a small helper pump with a low psi of 3-5 inline would work great.. So like any fuel pump for a carb application should work out fine for me eh? If it is ok to pump gas.. Can it pump diesel too??
1. yes you can see if there is crud in the tank, all you need is a light
2. not all fuel pumps will work. some will disolve internals with diesel. Make sure it is disel compatible.
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The tank has a screen inside it. Pull the sending unit and you'll be able to see it. It's probably gummed up with rust. If it is, I would pull the screen, clean it out, and then force out all of the gas through the OUT line, with the rubber hose disconnected. You may have a tank full of scaling rust (it was a gasser after all: they tend to rust the worst). Use the exhaust of a vacuum cleaner, or an air hose with the return hose and vent hose pinched. Put it into the filler neck with a rag wrapped around it. It will force out that fuel in a hurry.
If it's NOT clogged, then my guess would be a clogged return line or vent hose which is causing cavitation in the tank.
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Was this originally a gas car? With a fuel pump in the tank? Just converted a mk2 car, had to hotwire the pump in the tank and have it running(or remove the pump and change the sending unit), or I ran out of fuel with about 3/8 of a tank left.... Just a thought.
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Guys thank you so much for the replies, I am still at work! Thus the replies via cellular device ;)
I will pull the seat then for sure after work and check out that screen, hopefully its plugged up :)
Yes on an mk2 diesel swap it is necessary to remove or utilize the in tank fuel pump.. On the mk1 (mine being a CIS car) there was no in tank pump, there was a high pressured pump just outside the tank that supplies the CIS fuel distributor with just under 80psi.. This fuel pump has been removed and a rubber hose connected from hardline to tank outlet. Not to mention the car has been through countless tanks since February.. It is %100 fuel related tho.
Anyone know of any good inexpensive pumps that are diesel compatible?? That I can get here fast!!??
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I'm using a Faset brand prime pump. Its been on my truck for three years now, no probs.
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I had this same issue on my TDI. Intermittent power loss and finally a no start. It was a clogged fuel inlet screen in the sending unit. A drill bit took care of that little issue, lol. Stupid check valves! >:(
If you're looking for a lift pump that's stock, we're in the process of converting our 87 Cabriolet to diesel. It has an in tank lift pump, 5-7 psi. There are a few people using them on the Tex with no issues. I dunno how it will hold up when I start running high concentrations of biodiesel though, time will tell.
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Go to Autozone and get the Mr Diesel fuel pump. 12psi is fine for the VE. I pushed 20+ psi in my Dodge truck. Truck had better top end and got me 2mpg more.
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a Mr Gasket diesel fuel pump? 100-micron inline filter and 35gph at 5psi.. $60 not bad
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I've used a bunch of random ones form the junkyard. Sometimes veg oil will gum them up, and you have to beat on em a bit, but any will work fine for testing at least.
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So there is no restrictions in the lines, the fuel tank looks as clean as brand new, and it will pull fuel from a Jerry can on the floor..
What is going on here, no tell tale sounds of a pump failure.. as it runs just fine and dandy off the jerry can.. When blowing air down the return line I can here it bubbling in the tank through the vent line on the other side of the engine bay.. and then fuel shoots out the feed. When blowing air down the feed it bubbles, starts to push fuel through the pump and then squirts out the return.. DUNNO WHAT IS GOING ON!
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IF I RUN A LIFT PUMP IS 9psi TOO MUCH!?!?
I have heard someone run 15psi?
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Might you have a weak spot in a line someplace that is collapsing from the vacuum but not restricting because you are testing with pressure? I use a big syringe on the line going to the IP to pull fuel through or to the filter. You might try the same kind of arrangement. Mine is one of those plastic ones that is marked off for ounces and meant for mixing 2 stroke oil. It also works great on the OUT banjo of the IP to fill the pump after I break it apart to work on it. Thank goodness that nonsense is over with.
It has to be something!
A plug of something in the line getting caught on a turn or bend?
Totally baffling.
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When blowing air down the return line I can here it bubbling in the tank through the vent line on the other side of the engine bay.. and then fuel shoots out the feed. When blowing air down the feed it bubbles, starts to push fuel through the pump and then squirts out the return.. DUNNO WHAT IS GOING ON!
Does it do that with the fillercap on or off ? If blowing is building pressure inside the tank, there vill be vacum when ip is connected. Maby a blocked capvent or venthose in tank.
But, If you have an open filler neck and it does like you say.... Then I don't have a clue.. ???
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Because this car was gasoline not to long ago it doesn't have a venting gas cap, it has a third line that follows the hardlines back to the tank that I have snipped off in the engine bay. Pine needles? How does one get pine needles in on ones gas tank? Lol kev I think you had vandles! Ill pull the back seat and check the sender and look in the tank.. Can you physically see the fuel in the tank by looking through the tanks top on an mk1 jetta?
Also what I was thinking is a small helper pump with a low psi of 3-5 inline would work great.. So like any fuel pump for a carb application should work out fine for me eh? If it is ok to pump gas.. Can it pump diesel too??
no dude, the car had that problem when i got it. those needles were already there. and im not the only one its happened to either believe it or not.. there were a couple other users on here who have had pine needles in the fuel filter inlet banjo bolt.. i had a lift pump rigged up in my other rabbit too, because of those damn needles.. lol. anyways, fixed the pine needle problem, and left my lift pump there, but its purpose changed to primer pump.. you could be completely out of fuel, dump a gallon in the tank, turn the key on, wait for the fuel to start trickling back into the tank, then fire it up. i had a beer keg for a fuel tank, so you could hear the fuel returning to the tank.