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> BIG L-Jet problems, Comments welcome
srthompson01
post Apr 23 2007, 11:16 PM
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My fuel injection problem is complicated.

Bought the car ( 75 1.8L L-jet) not running. PO said air-flow sensor needed replacement and probably more.

Tried to start car and it refused to fire.

New plugs, wires, points.

I inspected the car top to bottom and found the oil reeked of gas, so I changed the oil.

I obtained all the manuals and tech articles I could find and checked the following systems. And then some.

Airflow sensor - Textbook perfect according to manual ( infinite resistance @ closed, 0 @ slight open etc…)

Fuel Pressure - 35psi ( manual recommends 35psi)

Temp sensor - 3Kohms @ 56 degrees ( pretty close relative to Bosch manual)

No noticeable air leaks.

Every 10 or so attempts to start the oil became fuel contaminated and required changing.

While disassembling the system I was able to get the engine to start with the cold start valve removed, functionally bypassing the airflow meter and running VERY rich and no throttle control.

While checking the injectors, they all functioned but were putting out HUGE squirts of fuel while the airflow meter was being bypassed and should not have been putting out ANY fuel.

I was unable to find any troubleshooting guide that fit my circumstances.

I have been over and over it in my head and I want to point my finger at a faulty ECU, however, all I hear is “ It’s never the ECU. Check this first….”

I put a carb on my beloved 914 and she runs well, but I want the fuel injection.

Any ideas????
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r_towle
post Apr 23 2007, 11:22 PM
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http://www.914world.com/specs/links.php
There is a link there for L-jet

This is the best L-jet site I have found for diagnostics.

You may start looking at the realy pack that is under the battery, it is what provides power to the injectors...if it is stuck in the wrong position, the injectors may stay running even though the AFM is not sending that signal.

It seems to be a common issue, the realy pack.

Rich
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Rockaria
post Apr 24 2007, 11:08 AM
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My Old L-Jet system came with two injectors stuck open. My local FLAPS had some rebuilt ones for not too much. They went in real easy and fixed the rich problem. I also took the Cold Start valve out of the system.

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QUOTE(r_towle @ Apr 23 2007, 11:22 PM) *

http://www.914world.com/specs/links.php
There is a link there for L-jet

This is the best L-jet site I have found for diagnostics.

You may start looking at the realy pack that is under the battery, it is what provides power to the injectors...if it is stuck in the wrong position, the injectors may stay running even though the AFM is not sending that signal.

It seems to be a common issue, the realy pack.

Rich
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dr914@autoatlanta.com
post Apr 24 2007, 02:52 PM
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check the air flow meter for a sticking flap and then check to see if the first three wires coming from the control unit (they are in a bundle together) are not grounded. (some 1.8s have an altitude compensator wiring loom coming from the control unit, and some owners ground these wires causing very rich running.
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srthompson01
post Apr 24 2007, 07:11 PM
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I tried to be as thorough as possible. I want to try the FI again, but the carb does work better than I expected from what my fellow club members report about them.

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jim_hoyland
post Apr 24 2007, 09:34 PM
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As a long time 1.8 L-jet'r, I agree with all of the above. Don't underestimate the potential for air leaks on hoses and fitting that look ok.

I've installed a vacumn gauge to the plenum to monitor any loss of pressure--leaks.
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alpha434
post Apr 24 2007, 09:48 PM
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Hehehe....

Broken rings.

Compression test.
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srthompson01
post Apr 24 2007, 11:20 PM
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compression is good, car cruises easily at 100mph. and still gets 30 mpg.

I just figure if I am going to pull the carb and spend at least a day trying to get the FI to work I need the experts opinions before I put it under the wrench.

Nothing is going to tick me off more than all that time, effort and $$$ to put the FI back together and have it still not work, when the carb did.

Adding to the frustration, I live in a very rural area and if I need any parts I have to order them, usually online, usually about a week.
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ClayPerrine
post Apr 25 2007, 02:07 PM
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Plan a road trip to Ft. Worth one day this summer. Load the parts up in the car, and I will help you get it working again.
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srthompson01
post Apr 27 2007, 01:20 PM
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Thanks Clay I'll do that this summer.

I don't feel so bad since so few others had any ideas.

I'm ready to lose the carb, but not not at the cost of losing my best toy.

Stephen
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TheCabinetmaker
post Apr 27 2007, 04:21 PM
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Road trip? Did I hear road trip? (IMG:style_emoticons/default/driving.gif)


Hey, this is my 3000th post!!!!!!!!!!!!
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ClayPerrine
post Apr 28 2007, 08:23 AM
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QUOTE(vsg914 @ Apr 27 2007, 05:21 PM) *

Road trip? Did I hear road trip? (IMG:style_emoticons/default/driving.gif)


Hey, this is my 3000th post!!!!!!!!!!!!



Hey Woody!

Can you build this and bring it with you?? Make it in some wood that I can stain with a nice cherry stain to match the rest of my house.

Attached Image

Yea, I know the drawing is a crappy scanned copy. It is the only one we have. And Yes, it is in Spanish. The hispanic "carpenter" that the builder had tried to build this 4 times, and failed miserably, even after I paid to have the blueprint translated to spanish. Seems he couldn't read a blueprint. This is the only copy we were able to get back, and we salvaged that from the trash.


Oh.. and how much to build it???


(IMG:style_emoticons/default/hijacked.gif)
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TheCabinetmaker
post Apr 28 2007, 06:35 PM
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QUOTE(ClayPerrine @ Apr 28 2007, 09:23 AM) *

QUOTE(vsg914 @ Apr 27 2007, 05:21 PM) *

Road trip? Did I hear road trip? (IMG:style_emoticons/default/driving.gif)


Hey, this is my 3000th post!!!!!!!!!!!!



Hey Woody!

Can you build this and bring it with you?? Make it in some wood that I can stain with a nice cherry stain to match the rest of my house.

Attached Image

Yea, I know the drawing is a crappy scanned copy. It is the only one we have. And Yes, it is in Spanish. The hispanic "carpenter" that the builder had tried to build this 4 times, and failed miserably, even after I paid to have the blueprint translated to spanish. Seems he couldn't read a blueprint. This is the only copy we were able to get back, and we salvaged that from the trash.


Oh.. and how much to build it???


(IMG:style_emoticons/default/hijacked.gif)



Can I build it? But of course. Can i bring it with me? not in a 914!!!!!!!!!!!!!
I'll work on a new drawing and get it to ya. Then you can take a red pencil and draw all over it, and send it back to me.
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