L-jet AFM replaced, but the car won't stay running. (SOLVED) Options

[malcolm2]

I am searching for a 7 pin AFM. I saw on a post that Fuel Injection Corp sells them. Their website says they have zero in stock. I will call them tomorrow.

I also see that AA has them $300 includes $100 core charge.

Anyone have another vendor they have used? Or a 75 7-pin that they will loan me for troubleshooting? I have one lead here in town, but I am not yet sure that it is 7-pin.

Anyone know what the difference in part #'s might be?

is a 7-pin the same? I see that lots of VWs had L-jet with a 7-pin AFM.

[malcolm2]

I am moving slowly on this problem.

I never heard from anyone that had a 7-pin known good AFM. So I purchased what I thought was a rebuilt one from EUROCARS9101. They had one they called REMAN! with a warranty etc....

It will be here Friday. I got tired of waiting and I have the BENT AFM that ran in my car for 25K miles and the OLD tired one that I bought from San Diego that could be bad cause my car won't run with it installed. (IMG:style_emoticons/default/WTF.gif)

I took out the guts of the bent one, everything but the big gear and the spring. Cleaned things up and installed them in the San Diego unit that is not bent.

I was able to move the PCB about 1mm so the sweep arm is hitting a fresh track.....

I am now on my way to install it. (IMG:style_emoticons/default/driving-girl.gif) (IMG:style_emoticons/default/driving-girl.gif) (IMG:style_emoticons/default/confused24.gif)

Those that pray, please say one for me.... Back in about 20.

[malcolm2]

God could not help either. Pretty much the same problem. It struggles to start unless I use the gas pedal, then it will not idle.

If I get the revs to 2000 with the pedal, it will stay there, but it is stumbling slightly. Let off the pedal and it dies.

SO now with the guts of an AFM that I know were good, I basically get the same result.

The only thing I did not transfer was the gear and the spring. Could the spring be too tight not allowing the flap to move enough at idle?

I will have a 3rd unit to try tomorrow, so maybe the pray-ers should give me one more days worth. (IMG:style_emoticons/default/rolleyes.gif)

[Root_Werks]

A vacuum tester is an excellent way to ensure there are no leaks in any components. Can’t count how many times I heard of someone chasing a K-Jet or L-Jet running problem only to find out the can on the dual vac dist. Leaked or something similar. It still sounds like a vac leak to me or something in the valve train system. Have you done a leak down? A burned intake valve might now show telling results on a compression test, but often show on a leakdown.

Keep at it, you'll get it figured out.

[malcolm2]

a vacuum tester sounds AWESOME. How does it work, can you buy one, or do I make one?

I got my nice clean REMAN! eurocars9101 ebay AFM today. Installed it.... and you guessed it: very little change.

It started a little quicker and ran a bit smoother (forced by the acell pedal). But it started and was slower to die. Gave me enough time to jump out of the seat and reach in for the throttle body and control the engine.

Again, it ran very ruff, even at 2500 to 3000 RPM, and will not idle, but is slower to die.

I'll get a video in the morning.

My plan is to go thru all the Trouble Shooting tips here once again. I will crawl under and do the HATED valve check. Probably will do the compression test 1st.

I pulled the resistor pack and checked the condition of the wires. everything looked good. It seems that the 4 tubes are connected at the bottom and wired to the 5th tab. I checked continuity from the 5th tab to each remaining tab. Is there a bench test for that thing?

I am going to be back at it in the AM, chime in with anything that we have missed so far. Disty vacuum can is a new one, so I will be on that for sure!

[zach914v8]

a vacuum tester sounds AWESOME. How does it work, can you buy one, or do I make one?

I got my nice clean REMAN! eurocars9101 ebay AFM today. Installed it.... and you guessed it: very little change.

It started a little quicker and ran a bit smoother (forced by the acell pedal). But is started and was slower to die. Gave me enough time to jump out of the seat and reach in for the throttle body and control the engine.

Again, it ran very ruff, even at 2500 to 3000 RPM, and will not idle, but is slower to die.

I'll get a video in the morning.

My plan is to go thru all the Trouble Shooting tips here once again. I will crawl under and do the HATED valve check. Probably will do the compression test 1st.

I pulled the resistor pack and checked the condition of the wires. everything looked good. It seems that the 4 tubes are connected at the bottom and wired to the 5th tab. I checked continuity from the 5th tab to each remaining tab. Is there a bench test for that thing?

I am going to be back at it in the AM, chime in with anything that we have missed so far. Disty vacuum can is a new one, so I will be on that for sure!

Vacuum tester

No tool box is complete without one.

[malcolm2]

Vacuum tester

No tool box is complete without one.

I hope it comes with some instructions.... I have quite a few Harbor Freight tools. I can't believe I never ran into this one while shopping.

I will make a point to get one.

[malcolm2]

I started the car this morning, messed with the disty and the button. checked the Ohms on the coil. Bypassed the TS2 and saw no improvement.

And now I remember why I hate dealing with the valves.... I need to back-date my exhaust. Valves and ALT work require the exhaust to be removed on a 75. (IMG:style_emoticons/default/barf.gif)

I did compression tests today and checked the valves on one side before it became MILLER TIME.

I am concerned about the compression I thought it should be more like #4:

#1 95
#2 100
#3 75
#4 110

I wish I had done a comp test right after the cam break in, then I would have a base-line, oh well. What do you guys think?

1/2 valves checked out. I have chromoly pushrods and 911 swivel feet, so I just check the swivel foot for spin. All 4 on the drivers side would spin and the rockers only clicked just a bit, so I have 0 lash.

3/4 exhaust comes off tomorrow.

[BillC]

If your valves check out, you may want to look into borrowing a smoke tester machine.

They work sorta like a vacuum tester, but in reverse. You hook the machine up to your throttle body or to a port on the intake manifold, and then it pumps smoke into your intake. If there's a leak, you'll see a stream of smoke from the leak. They work well and can save a lot of time looking for a vacuum leak. The big drawback is they are quite pricey -- I did a quick look on Amazon, and the decent-looking machines start at ~$800 and go up (that's why I suggested trying to borrow one).

[malcolm2]

BACK TO BUSINESS..... I have finally checked, adjusted and re-checked my valves. Each cyl at TDC, I set the corresponding valves to zero lash. My chromoly push-rods were spinning, my swivel feet were spinning, wiggle the rocker and I got no clicking.

I re-checked compression, hoping to see a GRAND improvement.... I did not. All cylinders were within 5 psi of the pre-valve adjustment check. Except #3. It has now risen to 95.

#1 95
#2 100
#3 95
#4 110

I plan on putting the car back together this evening and returning to FI troubleshooting and air leak hunting.

any other suggestions?

[zach914v8]

BACK TO BUSINESS..... I have finally checked, adjusted and re-checked my valves. Each cyl at TDC, I set the corresponding valves to zero lash. My chromoly push-rods were spinning, my swivel feet were spinning, wiggle the rocker and I got no clicking.

I re-checked compression, hoping to see a GRAND improvement.... I did not. All cylinders were within 5 psi of the pre-valve adjustment check. Except #3. It has now risen to 95.

#1 95
#2 100
#3 95
#4 110

I plan on putting the car back together this evening and returning to FI troubleshooting and air leak hunting.

any other suggestions?

Clark I know you have been having issues here. Make no mistake I have zero L-jet, D-jet or any other Bosch injection knowledge. Its not what I do. But the guy that owns the shop I manage is a Bosch fuel injection whisperer. He was a Porsche and Audi factory trained technician in the 70's and 80's. He is a very cranky old coot and hates to be bothered with much of anything.

That being said I brought up you issues with him. Of course he told me that vacuum leaks are huge on these cars. I discussed with him what you have done so far. He asked me if you popped the top on the AFM and manually played with the flap with the engine running? So have you? Also he mentioned that there are small adjustments that can be made to make up for a worn engine by popping a cap on the AFM and adjusting it?

But most of all he said it sounds like to him that you just have a bad AFM. I hope something here can help you if not maybe PM me and see if I can talk him into taking a phone call from you.

[jim_hoyland]

Have you checked the continuity of all the wires going to the brain ? Reason I bring it up is I was cleaning a space FI harness and noticed some worn wires

[malcolm2]

He asked me if you popped the top on the AFM and manually played with the flap with the engine running? So have you?

Also he mentioned that there are small adjustments that can be made to make up for a worn engine by popping a cap on the AFM and adjusting it?

But most of all he said it sounds like to him that you just have a bad AFM. I hope something here can help you if not maybe PM me and see if I can talk him into taking a phone call from you.

Have not opened this, newest AFM. I know about the "playing with" deal and hope to get to that point. I am going to have to find a way to hold the idle. It won't idle long enough for me to even get out of the car and grab the TB cable. broom stick time i guess. (IMG:style_emoticons/default/piratenanner.gif) (IMG:style_emoticons/default/piratenanner.gif)

3 years ago, I did "adjust" the spring on original AFM when i made the engine a 1911.

I thought my 2nd AFM might have been bad. It was old, previously rebuilt, guts were kinda rusty looking, but then I put the guts of my bent one into it. The car acted the same with AFM #3 (guts from #1) as it does with #2 and now #4. I think "bad AFM" may now be ruled out or at least put on the back burner.

a bad ECU has been discussed, Not sure if there is a test for that. I think I could ring out the wires easily enough tho.

[timothy_nd28]

I was on the phone with him, turns out that his plugs are fouled (except number 3 cyl, possibly from his intake leak). Clark, you should post the picture of your plugs on here for others to see.

I think he's running rich. I tasked him to attach a air/fuel gauge analyzer tomorrow and document the readings at different RPMs.

[zach914v8]

He asked me if you popped the top on the AFM and manually played with the flap with the engine running? So have you?

Also he mentioned that there are small adjustments that can be made to make up for a worn engine by popping a cap on the AFM and adjusting it?

But most of all he said it sounds like to him that you just have a bad AFM. I hope something here can help you if not maybe PM me and see if I can talk him into taking a phone call from you.

Have not opened this, newest AFM. I know about the "playing with" deal and hope to get to that point. I am going to have to find a way to hold the idle. It won't idle long enough for me to even get out of the car and grab the TB cable. broom stick time i guess. (IMG:style_emoticons/default/piratenanner.gif) (IMG:style_emoticons/default/piratenanner.gif)

3 years ago, I did "adjust" the spring on original AFM when i made the engine a 1911.

I thought my 2nd AFM might have been bad. It was old, previously rebuilt, guts were kinda rusty looking, but then I put the guts of my bent one into it. The car acted the same with AFM #3 (guts from #1) as it does with #2 and now #4. I think "bad AFM" may now be ruled out or at least put on the back burner.

a bad ECU has been discussed, Not sure if there is a test for that. I think I could ring out the wires easily enough tho.

I will ask him tomorrow if he knows a way to test an ecm... but I imagine he will probably mention a break out box or something of that nature.... but then again maybe not.

[zach914v8]

I was on the phone with him, turns out that his plugs are fouled (except number 3 cyl, possibly from his intake leak). Clark, you should post the picture of your plugs on here for others to see.

I think he's running rich. I tasked him to attach a air/fuel gauge analyzer tomorrow and document the readings at different RPMs.

Ok, thats good stuff.

[JB620]

So take this for what it's worth, which is not much, but have you checked the two seals on the oil filler cap for your vacuum leak? Seems too simple, I know. I'm no mechanic but I have read a number of threads where this is an often overlooked place. Just spit-ballin' here... carry on.

[malcolm2]

Here are the plugs. I think they have about 20K miles on them. I replaced with new tonight. truthfully #3 is not that much different. You can see just a bit of white ceramic, but not much.

[

[zach914v8]

They look a bit rich, but I not seeing anything here that stop the car from running. I have pulled much worse from late model cars that were running fine.

[malcolm2]

So take this for what it's worth, which is not much, but have you checked the two seals on the oil filler cap for your vacuum leak? Seems too simple, I know. I'm no mechanic but I have read a number of threads where this is an often overlooked place. Just spit-ballin' here... carry on.

I have heard that too. Back when the car would run.... I actually pulled the filler cap off once.... the car died.

The seals are there, they are flexible. Not really sure how to test them. This might be a good place for that $800 smoke machine.

Maybe I can find some other way to cap the oil filler off to test it? I'll look at them a little closer. I have replaced the cork seal there tho.


Lots of stuff plugged up for testing.