Printable Version of Topic

Click here to view this topic in its original format

914World.com _ 914World Garage _ Should I keep the fuel injection?

Posted by: skeates Jan 30 2006, 09:11 PM

My car has a 2056cc engine in it, but with the stock L-Jet fuel injection. And when I was modifying the engine I went ahead and put in a slightly more radical cam. I was wondering if I shoulf keep the L-jet and try to "tweak" it to privide enough fuel, or if I should switch over to Webbers?

BTW, does anyone out there have information on the diferences between the fuel injectors on the 1.8L vs. the 2.0L (mainly flow rates).

Posted by: r_towle Jan 30 2006, 09:14 PM

Describe what you mean by a slightly modified cam...

Exact details will get a better answer...

The overlap etc will effect how the car runs...

It all depends on the cam.

Flow rates are on pbanders site on rennlist.

Rich

Posted by: skeates Jan 30 2006, 09:15 PM

Unfortunatley I don't have figures on lift or durration with me. All I can say is that the cam is only slightly more radical than stock... In the mean time I'll try and get those figures

Posted by: r_towle Jan 30 2006, 09:29 PM

Do some searching here...

The cam on ljet has been discussed with regards to how it affects the ljet FI system..

Basically the reverse air pulses created by a cam with alot of overlap can close the flapper..

So, you need those cam numbers to make a choice.

Rich

Posted by: skeates Jan 30 2006, 09:47 PM

Is there anyone as knowlegable on the L-jet system as pbanders is on the D-jet? I'm wondering if swapping out the 1.8L injectors for the 2.0L injectors and then ajusting the tension on the Air flow meter (for fine tuning) would allow the Fuel Injection to keep up with the extra displacement...assuming of course that the cam overlap isn't forcing the flap closed... thoughts

Posted by: r_towle Jan 30 2006, 09:53 PM

http://manuals.type4.org/ljet/

Posted by: bd1308 Jan 30 2006, 09:57 PM

porsche did just that. they took the 1.8 systems left over from 75 and made the 912E and used up the extra 914 engines....or so the story goes.

it can be done. I dont know how to do it yet.

It has something to do with that gear thing at the bottom of the electrical portion of the afm...

b

Posted by: Mueller Jan 31 2006, 12:51 AM

what you need to invest in is a good Wide band 02 reader such as one from Innovate Motorsports (if you have a laptop computer you can get the cheaper $200 model)

this way you are not guessing and have a less chance of screwing up your engine....do not start swapping parts from one version to another....

here is another L-Jet guide, it's for the 912E, but has some good info worth reading

http://www.texas912.org/912E%20Tech%20Data/912E%20FI%20Technical%20Manual.pdf

With the WB02 sensor, you can see what you motor is doing and possibly adjust the fuel pressure to compensate if you need more fuel (to a point)

Does the car run now? If so, then chances are your cam is not too aggressive......

I cannot find my notes for the 1.8 injector flow rates, but they are less than the 1.7 and way less than the 2.0, but don't let that fool you, the 1.8 injectors are good for over 160-180hp if my memory is vaguely correct and you are well under that limit I'm sure....

Posted by: skeates Jan 31 2006, 12:10 PM

Yes, the car runs - and I thought that I had it diled in fairly well. But when I'm having issues with the oil temps getting too high if I drive the car for much longer than 15 min.

I thought that I had solved this problem after ajusting the fuel injection a bit because it ran very well for a little while. I ran it hard for a good 30-45min and the oil temps never went above 210 F, and then when I parked the car back in the garage I let it idle for about 10 min abd the temps dropped down to 180 F like one would expect.

Now, even if I let it sit at idle, the temps will continue to rise above 210 and I'm sure beyond 220-230 if I let them. My idea right now is that the fuel injection can't support the engines increased displacement and it is therefore running too lean (which would cause it to run hotter correct?)

Posted by: ClayPerrine Jan 31 2006, 12:15 PM

Use a wideband O2 sensor or a CO meter to properly adjust the mixture.

I ran a L-Jet on a 2.0 for almost a year with no problems.

Posted by: skeates Jan 31 2006, 12:22 PM

What modifications did you do to the L-Jet (if any) in order to get proper mixture on a 2.0L?

Posted by: ClayPerrine Jan 31 2006, 12:24 PM

QUOTE (skeates @ Jan 31 2006, 12:22 PM)
What modifications did you do to the L-Jet (if any) in order to get proper mixture on a 2.0L?

Nothing.

The extra air pulled by the 2.0 made the AFM flap open farther. That made the mixture correct for the 2.0.

I ran 3% CO and the car ran great!

Posted by: skeates Feb 10 2006, 12:21 AM

Ok, so it has taken a little bit of time but I think that I have located some specs on the cam in my engine. I know that the brand is Engle, but when I did some research on their website I descovered that they don't in fact make cams specifically for the type-4 engines. I ordered the cam through a VW mechanic. Does the type III or II have the same cam design as the type IV or am I going to need to replace the cam altogether?

Aside from that here are the specs of the cam I believe are in the engine now...

Valve Lift: .420"
Advertised Duration: 276 Degrees
Cam Lift: .383"
Duration @ .050: 236 Degrees

From my research on the web cams this seems to be a mild carbureted cam grind. Has anyone else out there used the engle cams? I'm wondering if this might be contributing to my overheating...though I'm also pretty sure now that a major part of the overheating is that I don't have any of the engine bay seals

Posted by: Mark Henry Feb 10 2006, 08:15 AM

Engle only makes Type1 (type 2 & 3 are type 1) cams as far as I know. Are you sure it's not an Eagle cam made by CB performance?

QUOTE
though I'm also pretty sure now that a major part of the overheating is that I don't have any of the engine bay seals

Ummm yep...that's part of your problem.

Without a wide band meter you're just pissing in the wind.

The L-jet injectors are not very flexable but are the ones you should use on an L-jet.

I'd get the wide band and go with aftermarket FI before switching to webers.

Posted by: Mark Henry Feb 10 2006, 08:23 AM

BTW anyone that wants to tell me that a type 2 engine is a type 4, do your homework first....don't make me pimp slap you.

Posted by: r_towle Feb 10 2006, 04:17 PM

I come wearing armor...

I thought the type 2 bus of the 70's (bay window)and the early vanagon was a type 4 motor...

Slap away...

Rich

Posted by: type47 Feb 10 2006, 05:14 PM

QUOTE (ClayPerrine @ Jan 31 2006, 10:24 AM)

QUOTE (skeates @ Jan 31 2006, 12:22 PM)
What modifications did you do to the L-Jet (if any) in order to get proper mixture on a 2.0L?

Nothing.

The extra air pulled by the 2.0 made the AFM flap open farther. That made the mixture correct for the 2.0.

I ran 3% CO and the car ran great!

do you have anyway to compare performance of a stock 2.0 D-jet and a stocke 2.0 w/L-jet? or any comments on the comparison?

Posted by: type47 Feb 10 2006, 05:17 PM

QUOTE (r_towle @ Feb 10 2006, 02:17 PM)

I thought the type 2 bus of the 70's (bay window)and the early vanagon was a type 4 motor...

would that be "body style"? bus is a type 2 body with a type IV motor?

Posted by: Mark Henry Feb 11 2006, 09:39 AM

About right, Type 2 up to 1971 had a type 2 engine and that was just a Type 1 engine with very minor differences.

From 1972 till 1982 1/2 the Type 2 got the type 4 engine.

I still get guys telling me I'm wrong, insisting the type 2 and type 4 engine are the same thing.