VWDiesel.net The IDI, TDI, and mTDI source.
Engine Specific Info and Questions => IDI Engine => Topic started by: BRimpossible on April 23, 2016, 10:17:45 pm
-
Hello I have a Vw rabbit 81 pickup with 1.6 hydraulic engine that I just barely swapped from a tired 1.5. 5 speed as well. It runs well and did a lot of switching with new parts such as new fuel injectors and lines. Right now the problem is that when I drive it and reaches the max rpm it would hesitate little bit like slowing down for a sec or 2 then back to normal. Happens quite often. I checked the IP and seems fine no changes after adjusting it. Dirty fuel perhaps? I haven't really checked the fuel tank and thinking might need to replace the fuel filter there. New fuel filter under the hood so that's checked off the list.
-
Oh also the top speed is about 60-70mph. Some days it drives well other days it would drive weak like it couldn't reach 60 mph but then I live by lots of hills. Those hills aren't steep and yet my truck would struggle sometimes. Sorry for lots of questions not a lot of Vw rabbit owners around here where I live.
-
Did you put a new fuel filter on it? It almost sounds to me like you are developing a lack of fuel at the high end. Maybe it is developing a vacuum and pulling air between the filter and the IP? You may find that backing the fuel screw in just a bit might give you more even speed at the top.
-
Yes new fuel filter by the engine but not the fuel tank. It was sitting for a yr with 1/4 tank of fuel. Any ways thought I'll give a update of what o have noticed. When it sits for few hours and I drive it in city it would drive great but once I get to highway it will buck then get worse the farther I drive it. So it does indeed sound like fuel starvation
-
1/4 full tank for a few yrs sounds like the problem to me. Pull the gauge sender on top and start cleaning. Or pull the lower hose and clean. Either way you are not doing well with whatever is in there and no sense adding new gas to a bad tank situation.
-
Thanks I was afraid of that. I'll have it cleaned up and use air compressor to clean up the lines as well from tank to filter.
-
I'd test by bottle feeding first... clear lines in and out of a clean container of fuel to/from the IP.
Don't guess. Test.
-
Check that all pump mounting bolts are tight.
-
Thanks guys. Tyler ill for sure do that test first.
The ip pump bolts were plenty tight but I'll double check. They were tight before and after and still remain the same issue.
-
To be clear, the bolt of concern would be the fourth one under the metal lines.
-
Did the test from a clear bottle filled with diesel and clear vinyl lines for temporary testing. Drove it and it had plenty of power and no more bucking. Time to switch out all the rubber lines and fuel filter along with gas tank cleaning. I'll adjust the IP again because it smoked white at the first start up in the morning.
-
Oh also when I started the test, fuel was foaming from the return lines and took a while to clear up. The fuel going in the ip wasn't bubbling which is good.
-
YES it is normal for an IP that has air in it to take awhile to clear it out. It really needs to get revved up for a bit to make that happen. Just a lot of places in there that harbor air for some reason. Sounds like you nailed it. I thought about the bottle feed long after I posted. Glad others caught that. It is so simple to do and isolate the problem to the IP or the two lines connected to it by using that method.
-
Should I go ahead and drain the fuel or just drive until tank is empty? I have like 1/2 tank full still. If I have to, I'll reroute the line to 5 gal gas tank for temporary until I can get the gas tank clean out.
-
Personally I'd drain it - I know disposal is a bit of a ***.
If the fuel is contaminated then you're not doing yourself any favours running it through your pump. Remember the pump circulates something like 90% of the fuel that goes in the inlet out the outlet again back to the tank so if the fuel in the tank is full of gunk it's going to pass through the IP hundreds of times before you actually use it all up. The factory fuel filter is something like 30-50 micron, it isn't particularly good at filtering so don't rely on it alone to keep the rest of your fuel system safe.
-
Thanks I decided to hook up to 5 gal tank and put it on the bed.
-
Yes better, much better to go with known clean fuel than route that dirty gunk around a bunch of times or pump it to another storage area. Like it was said most fuel gets pumped through and is not used. That is so the pump stays cool as it does its job.
-
Unhooked the gas tank and used the 5 gal tank on the bed for temporary but found out that the hard lines or rubber lines before the fuel filter is clogged. Basically the ip is getting foam fuel so I'll need to reroute the fuel line again front of the hard lines before the fuel filter to see if that works better. Just struggling to see how I can make this work for temporary. I use this pickup everyday and I don't have much free time to clean up the whole fuel system.
-
Sounds like your fuel lines may be your actual issue then... Not sure about the Caddy, the Mk2 had a water separator near the rear axle that caused a lot of similar problems...
You CAN "polish" the fuel in your tank if you can get your hands on a transfer pump and a good fine filter with a proper water separator - something like a Racor or whatever. Set up the pump to suck out the tank feed, route through the filter and return it to the tank, leave it running overnight for a few nights. I'd feel pretty confident to use the fuel at that point provided you don't have any signs of algae in the tank.
-
Well took off the inlet fitting that goes to the fuel filter, it was clogged with dirt. Cleaned it up and now I have pure fuel coming to IP from the 5 gal tank. I still think I'm gonna clean up the gas tank and blow air in the hard lines to prevent that from happening again. Thanks everyone for your help. I can drive the caddy and actually enjoy it again.
-
Did you clean mash in tank?
-
OK for now you are mobile and you know that there is crud in the tank that needs to come out. I think I read that you are now using the original line for feeding the fuel filter. That line is blown out clean and hooked to a temp 5 galloner? That will get you by for ever if you don't mind the fuel risk of running out of fuel early, no gauge and potential for contamination.
Find some time and pull the tank or pump it out and clean the inside with filtered fuel. That gob of dirt in the inlet line is all the evidence you need to show you have a dirty tank.
-
Took the gas tank out, drained the fuel. Inside is very dirty and black on the bottom. Fuel sender unit has hard dirt built up on it even though it worked well. I'll buy a restoration kit for the tank so it will be clean again. Filter is black as well
-
Great.
-
Did you clean mash in tank?
Good point
how does the intank screen look?
-
By reading on forum I remove first time on deal with tank,many years ago.
Never see point for our motor,it`s more eazy to change fuel filter.
Just mesh crimped on metal pick up tube 8mm in case of my Fiat
-
It's not uncommon for algae to grow in the tank. It makes a black slime that will easily block the pickup screen which is why folks recommend checking it out. Mk2+ have an access hatch to get at the pickup making it simple enough. Not sure about Mk1.
Sent from my XT1097 using Tapatalk
-
On the MK1 you just pull up the rear seat and then undo some screws and tap the sending unit to release it from the tabs. Then you wiggle out the sending unit and you have a clear view and about a 3 inch hole to work in. Just don't do it with more than a half a tank of fuel as it may be up on the sender end if not level. Besides you want to be low on fuel to get the most gunk out you can. Filter with some of those 10 micron socks inside a PVC tube it works for veg oil.
-
When you swapped engines, what did you do with the exhaust system?