Lookin for a little help here.
Removed my perfectly good running Ljet to install carbs. That did not work out because of linkage problems. Another story for another thread.

Ljet is back on and fires right up everytime but stalls everytime. Can give it gas but it will stall out when I let it try to idle.

Anyboby with any ideas on what I am missing or what could be a cause of this trouble.

Thanks in advance for replies.
Ken

Check:
1. The AFM connector is attached; this is pretty common. Car starts mometarily off the dual relay, but the AFM signal to the fuel pump fails 'cause it's not connected
2. Vac hose leak, one may have broke open during the uninstall See: http://www.pelicanparts.com/914/technical_...4_18FI_diag.htm for hose diagram
3. Wires ae dual really are snug

4. Others will chime in on this, these are the ones that get me in trouble

Thanks for the ideas, Jim....

1. Hooked up. Ive done this one before also. I went ahead and removed it for fun and it is different acting when I start car. Without AFM it revs to 2000/3000 rpms. Mine it starts normal then runs like a tractor for a few seconds then dies.
2. Checked OK. Only have plenum to fuel regulator vac line. Mallory D so two on TB are plugged. I did have the two on TB connected to each other but now are plugged. That should be the same thing, right?
3. Thought this might be it. Was pushing on FI part of relay and it like snapped into place I thought. Still acts the same.

4. Come on others let me hear your thoughts.

Im wondering about Fuel Regulator?

Gotta get this thing going before Talemena. Hopefully without a tow to my real mechanic!!

Ken

If you're certain the rest of the engine is good (ignition timing, dwell, valve clearances, vacuum fittings, etc.), you might consider turning up the idle speed and playing with the idle mixture screw.

Fuel injection in general and LJet in particular are very vacuum dependent. Check that you didn't crack the rubber in the connection to and from the AFM... Check to see that you have all vacuum hooked up correctly and the lines are not cracked.

Fuel pressure? Carbs use a low pressure pump....didya put the right pump back in?

Correct FP is back on. It acts like it is not getting enough gas after initial startup and that is why I ask about Regulator above.

Vac lines/throttle boot are new as of last summer so should not be damaged.

Don't think I can adjust Regulator on Ljet and I have played with the idle screw.


Will double check vac at TB and then check fuel presure.

Let me hear from someone on what kind of trouble pressure regulator being bad would cause? Do they go bad? Would putting pressure on it backwards hurt it?

Thanks, Ken

Putting the reg in backwards would cause the system to have very high pressure on the pump side and low pressure at the injectors. This probably wouldn't hurt the reg, but it might hurt the pump and/or some of the lines between the pump and reg. You would almost certainly be blowing fuel through the overpressure port on the fuel pump (assuming it's a three-port pump).

Just for reference, the reg should be the last device in the fuel-line loop before the line returns back to the tank. Fuel should enter the reg on the radial (side) fitting and leave the reg on the axial (center) fitting.

Dave,

I did not hook up the regulator wrong. I put pressure on wrong side of regulator by having supply/return hoses wrong. That ended up being a pinched line up front but I digress.

It is a 2 port pump. So I could have damaged pump but prolly not regulator?

Ken

How about the yellow wire connection:

My yellow wire was on the other rear connection when i took the injection off in a working state. I have tried both rear connections with no appearant difference. Thought about trying FP relay on that board to see what it does. I carried a relay there as a spare and it caused a rich running condition on my Ljet. Clay told me at RCR that that relay should not do anything on the Ljet setup.

Fuel Pressure looks good from time car is started till it stalls. About 35 psi.

Still searching for the answer

Thx for all the ideas

So let me ask this question.

Is the FP something that if bad could pressurize then all of a sudden lose its pressure OR is it a "it works or it doesn't" kind of thing.

Just wondering what else I could have done by putting the pressure on the return line. Sock in tank? Junk stirred up by pressure coming the wrong way into the tank?


I want to it......


Shameless Bump

Sounds like you didn't do any damage to the pump when you hooked it up backwards. If you've got fuel pressure, then you've got fuel pressure.

Another test for pressure reg -- pull off the manifold vent line from the port on the end of the reg. Run the pump and verify that no fuel exits the port. Occasionally, the reg will go bad and will pass fuel into this line, which will subsequently get dumped into the plenum.

Have you verified that the pump continues to run when the starter motor is off? Do this by slightly moving the flap of the airflow meter. Remove the meter from the rubber elbow and deflect the flap with your finger with the ignition switch on.

Good luck. Stay committed. I know this kind of thing can be really frustrating, but you'll sort it out and then the car will start and run every time.

-dave

Thanks for the ideas, Dave....

With key on when I move flap with my finger the fuel pump kicks in and nothing but air blowing out the back of regulator. I consider that good news eventho car is still not running.

Could throttle cable have anything to do with it? It seemed straight forward. Butterfly is closed all the way it appeared.

I used Liquid Tape and zipties on the harness to clean it up a little when it was out of car. Could I have broke a wire on blocked a connection? Is there another componet in the FI that would cause a stall?

Prolly gonna give it a few more days right now. Then I will attempt the carbs again since I now have the corrrect linkage.

Ken

Have you tested for power to the fuel pump when the engine dies? The flap in the Air Flow Meter (AFM) has to move open a little to make the fuel pump run and you have tested this and know it works. If you have a vacuum leak or air leak between the AFM and the Throttle Body (TB) there might not be enough air flow to hold the flap open enough to keep the fuel pump running.

Have you looked at the AFM flap? Does it move smoothly? Is the pop off valve in the flap intact and closed?

On a 1.8 there are several places where air leaks between the AFM (un-metered air) and the TB can occur. The connection for the big hose/duct to the AFM and to the TB. The connections/hoses to the Aux Air Reg and the Decel Valve. The connections/hoses for the crankcase breathe and EGR (if you have EGR). The oil filler cap, oil filler and even the valve cover gaskets. Since the 1.8 used a "sealed crankcase breather" system and air allowed in to the crankcase enters the intake system between the AFM and the TB.

Good Luck

Jim

Hey Ken, did you say the thing will stay running if you boot the throttle? It only dies at idle?

If so, maybe you should turn up the idle speed screw? (Probably already did this, right?)

The flap does move smoothly. Not sure what to look for on the pop off valve.

Have not checked power at pump after it stalls. What would this point to ?

Thanks for all the input.

Yes, as long as I'm in the throttle it will stay running and yes I have played with the idle screw.

Gonna triple check all vacum lines

thx for all ur input

It could point to the flap not staying open enough to keep the fuel pump powered up. Possibly not enough air flow to keep the flap open at idle.

You could (for testing only) jumper power to the fuel pump and make it run all the time, then see if the engine still dies at idle.

The pop-off valve is a round spring loaded valve (about the size of a quarter) in the AFM flap that pops open if the engine backfires into the intake. The idea is to keep the sudden pressure of a backfire from bending the flap out of shape. Not sure all the AFM had pop-off valves, it took them a while to figure out they needed them on the 914. The low compression of the 1.8 made them very sensitive to vacuum leaks and a small leak could cause them to run lean and backfire.
You need to see that the valve is seated flat in the flap of the AFM and the spring is holding it tight. You have to look from the air filter side of the AFM, may need a mirror and flashlight if the air filter housing is still attached to the AFM.

I notice in a early post you say "Only have plenum to fuel regulator vac line. Mallory D so two on TB are plugged." So what have you done for the Aux Air regulator hose connection and breather hose connection that go to the intake boot between the TB and the AFM?

This is the time in a problem that I back up and start checking things I am sure are OK. You had the complete intake system off and back on when you swapped to carbs. Look back thru all your intake connections. Injector seals in place, manifolds seated to the heads, manifold insulators not cracked, boots from the intake runners to the plenum tight, TB gasket in place, hose routing correct (the diagram, at the pelican link earlier in this thread, is nice). Quickly going back over the basics often uncovers something (often simple) missed.

You might be amazed at what someone on this forum can see in a few pictures of the engine compartment. There has been many a thread here where someone point out a problem just from a picture posted here.

Hang in there

Jim

Ken, have you verified your ignition timing?

Guess that is something I should have checked. I really did not think that I had done anything to effect timing by pulling the FI components?

Timing was there, no valve adjustment was needed when I pulled the system off the running car.

Will try post a few pics tonight after I get home. The AAR hose and breather hoses were/are in place.

Ken

Some overall shots
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components and aerial view
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Both sides of AFM
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Went back thru all harness plugs and vac lines. The Oil Breather line is not kinked it is for a Mercury and had the right bends to work. I have 1 old vac line, the one between plenum and AAR. All other lines, vac and fuel plus boot, where put on new last summer as well as injectors and AFM.

I will replace that old short piece. TPS plug was not tight but did not fix.

Could the AAR cause this. I cleaned with spray contact cleaner when I had removed from car. Could this hurt it?

Also wired FP to run all time and the car still stalled after starting with FP running constantly.

Thx for keeping the ideas/thoughts/solution coming...
Ken

Where you at on this ?

Back running....with 40 idf's

Was under pressure to have it running by 2mro for Telimena.

Thx for everyone's input

Ken

Sorry I'm late weighing in on this...
If you decide to put the Ljet back on, check these components first:

AAR and the Decel Valve - my 1.8 did the exact same thing, turns out the Decel valve casing halves were not sealed (vacuum leak).

Check the transmission ground strap. The injectors are grounded indirectly there.

Lastly, if the dwell is not properly set, this well cause stalls as well.

Good luck

No Decel or EGR.
I wonder if it is not somehow related to the AAR. When I removed the AAR I was able to see all the way thru. Not sure if this looked correct or not??