Gang, I need your help. I started out just running rich. So I made a very small adjustment to the AFM to lean it out. I also did a tune-up (cap, rotor, plugs and wires) No points (Compufire). I also replaced my ol faithful Bosch Blue Coil (12 years old) with the best I could find in a day (Standard Brand). Now I am running rich and with a nice case of hesitation and blubbering. Idle is good, but the minute I pull on the throttle a slight decrease on the RPM for a second then it picks up and blubbers at what ever point I pull the throttle up to. It does it at all RPM's. I haven't got on any stretch of road long enough to see if I can feel any hunting or jerking...I am almost certain that it would. I have tried to find posts on the site and I can't find any with my symptoms.

I checked all the vacuum lines for leaks.(cut old ends off and reattached)
Checked the Pressure Regulator, vacuum side for leaks.
Cleaned the throttle body (also made a rubber gasket for it)
Cleaned the throttle switch (removed all the carbon deposits on the points.)
Checked the AFM Flap for any damage (have you checked the price on these babies? Ouch!)

I am at a loss...any advice you might have would greatly be appreciated.

Thanks in advance...

it sounds like you have lean running conditions i.e. hesitation and blubbering...

if i recall right vw recommended the blue coil upgrade, to help cuting out

did you adjust the swiper (slight bend?) what is the c.o. and h.c. readings at all ranges

i had a compufire on a l-jet 2.0 bus that i had to switch back to points for the smog check because it was slightly misfiring (not noticably by ear). the c.o. normal but h.c. high from misfire

mike

I didn't pass idle test...so I didn't graduate to the 2500rpm test. The reading at idle were:

HC Standard 300pmm Car - 547ppm (FAIL)
CO Standard 2.5ppm Car - 8.82ppm (FAIL)
CO+CO2: 6
CO2: 8.7

I enrichened (turned screw to the right) same blubbery effect. (I am not a mechanic - "3rd times a charm" is my motto)

If I where to make any adjustments to the wiper (AFM) which way would you go?
Hope this helps...

Bad airbox. Oh, and BTW, "Standard" brand ignition components may be crap on Detroit Iron, but they're even worse on German cars. Ditch the coil. The Cap'n

now remember I didn't have the blubbering before the tune-up, coil and one turn left on the AFM dial...you really think that it just died durring the procedure ($500-$1200 gamble). Any other areas I could check?

Thanks for all your help...

Check timing and dwell? Temperature sensor?

Before I did my e-test, I leaned out the AFM while waiting in line for the test. Passed with flying colours and then turned the screw back to where it was before.

I've also been troubleshooting a "stumbling" issue under load. I have a known good AFM to swap out and will also test the pressure regulator.

Get a Bosch coil.

Get an AFM that hasn't been opened and DO NOT MONKEY WITH IT!.

If all the other parts are correct, you won't have to change a thing in the AFM. It is correctly calibrated for a good running engine.

How much do you want for the AFM + Shipping?

I actually just bought this from a guy on this board. I wanted to have a backup and something for troubleshooting. Post a WTB in the classifieds. I'm sure someone has an extra one they'll part with for a reasonable price.

If you can't find a AFM, contact Hwgunner. He was parting out a 75 and he might still have the AFM.

hope that helps.

-- brett

I will check it out. Thanks...

Replace that crap coil (as Cap'n said) with a good bosch blue.

If you get a new AFM, they have to be calibrated for the engine they are working with. To do this, you need a flexible gas analyzer and to adjust after driving.

Also, do you have the Smog pump equipment, EGR and a WORKING converter on the car? L-Jet car I had to get past smog (912E) only needed a tuneup and a new converter to pass.

My checklist for pre-smog on a 1.8 or 2.0 with L-jet:
x) Valves adjusted?
x) Vacuum leaks?
x) Cap/Rotor/Plugs/Coil in great shape?
x) Timing/Dwell set to stock? I believe it's 8.5º ± 1º at idle with the engine warm, vacuum hoses to the distributor plugged and disconnected from distributor.
x) Distributor advance/retard working correctly?
x) Exhaust leaks?
x) Converter in good enough shape?

That should about do it.

This is not quite true. If you get the CORRECT air flow meter for a 75 914 with a 1.8L engine, it will be correctly calibrated.

If you do that, please don't open it and mess things up trying to correct a problem with the root cause somewhere else. That is just a band-aid.

These guys don't wanna hear that, Clay. Forget strategy, concentrate on tactics ...

The Cap'n

Here is the check list from Brando... checked off a few but didnt understand a couple...can you clearify for me please...

x) Valves adjusted? Check
x) Vacuum leaks? Check
x) Cap/Rotor/Plugs/Coil in great shape? Check
x) Timing/Dwell set to stock? I believe it's 8.5º ± 1º at idle with the engine warm, Check
vacuum hoses to the distributor plugged and disconnected from distributor. Plug on the manifold as well?
x) Distributor advance/retard working correctly? ?
x) Exhaust leaks? Check
x) Converter in good enough shape? ?

Will a AFM from a vw vanagon work? I just thought for $20.00 at a "U"Pull It...it wouldnt hurt to try.

Thanks for all your help!!!

Tabs, Don't try to pull and swap a critical part like an AFS from kind another car. Sure, it may be a bosch part, sure it might have the right pin count but unless the part # is correct for your model/year 914 (if someone has the listing of BOSCH parts and can compare that?) I would stick with apples to apples.

As to your 2 question marks... On your distributor, it should have a breaker plate that moves forward and back and is vacuum controlled. That is what advances and retards the ignition timing. If you have a different distributor the car may not run in a condition to pass emissions testing, either too much advance at idle, not enough, etc.

Second question mark... Your car does have a catalytic converter on it, right? There is no way you'll pass current emissions testing without one.

No Cat. never did and always passed. I have had the car since '93, rebuilt about 5 years ago and have been doing general maintanence ever since. The fuel system has me stumped, and I don't have the right equipment to diagnose. I will keep hunting for a AFM... I did find a couple on ebay that were remanufactured from a company called "Federal Modul". here is a link

http://cgi.ebay.com/ebaymotors/Air-Flow-Me...emZ150291323890

Has anyone had any experiance with them?

1975-1976 1.8 L-Jet Cars come with a catalytic converter STOCK:
Exhaust with Converter Image
If you don't have one, it's time to look for one.

Chances are, you've passed the test previously very easy, but they've possibly enacted stricter regulations in the past year, hence failing.

Also, have you checked for a leaky Cold Start Valve?

That looks like mine...it's a Bursch. What part is the cat. ?

Only CA 1.8's might have a cat...not required equipment for the other 49 states [OR].

Only retard on the distributor [that was a real go-round one year with DEQ]

Hoses may look good, but still leak [btdt]

Is the flapper sticking at all in the box? This is what did in my last DEQ check years ago.

...now I've got a 74 -- no DEQ!

Are both oil cap seals in good condition and not leaking?

The 75 1.8 runs with a closed crankcase system................any air leaks through the oil cap really screws up the Air/Fuel mixture.

Just a thought.

No promises on success but I have a '75 AFM from a running car I swapped out to a 2.0 D-Jet some years ago. PM me and I'll ship it up for you to try. If it works, send me whatever you think is fair. If it doesn't help, ship it back with something to cover my shipping. Not interested in making money, just keeping our cars on the road.

Well all day tracing back to when the blubbering started, I remembered checking the relays on the relay board on the left side in the engine bay. I had taken them out to clean the connections and reseat them. I was thinking mabe I might have a bad one that is causing the blubbering. So I moved them around one by one and it started to run real rough. So I adjusted the CO screw and idle and tried the throttle.......no more blubbering. So I will take her down to DEQ and see what happens. Thanks for all your help...I wish I could buy you all a cold one.
Steve I might take you up on your offer if all else fails. That is really kind of you.

Wish me luck...

Uhh.. I can tell you that is not the problem. The relays in the relay board do NOTHING for the Fuel Injection on an L-jet car.

I know one of them is a relay for the fuel pump and a yellow wire plugs into a pin on the lower left of the relay board...it turns on the fuel pump.

Here is a rough diagram of where the wire plugs in. The "O" is where the yellow wire is right now:

------
| O
| |
------

Maybe someone can tell me how this should be set-up if this is incorrect?

Thanks,
Tab

Clay is correct. L-Jet uses the dual relay to operate the fuel pump. The only relays in use on the relay board is one for the heater fan and one for the optional rear window refroster. The sockets from front to back are:

- rear window heater
- power supply (D-Jet only)
- fuel pump (D-Jet only)
- heater fan

The yellow wire should be here (II in the picture below)


front
-------
| |
| O
-------
rear

Click to view attachment

The yellow wire is from the start circuit. It supplies power to turn on the fuel pump when the engine is cranking. It can be hooked to either of the 2 rear most spade connectors on the 4 pin plug on the relay board.


FYI, You can also use a piece of wire and a spade connector to crank the car by hooking to one of those terminals. That way if your ignition switch dies, you can still start the car without crawling underneath.

Ok...well I can tell you that after removing all the relays while the car was running it started running really rough. I then started putting them back-in careful not to put them in the same way. I was just going over everything that was done prior to the blubbering problem... after doing that the roughness is gone. There was a relay where the fuel pump goes...maybe it was shorting the system if it was bad?

That is weird, unless you managed to jiggle something else when you were removing the relays. The fuel pump relay wouldn't do a thing because it has nothing to energize it.


Maybe you bumped the voltage regulator? Low voltage will affect the l-jet system in weird ways.

I did check the voltage, but that was after I got it running right...it's at 14 volts at idle...should it be 13 or so? maybe the regulator is going?

doesn't the fuel pump run thru a relay on the board? if it does it can be a weak relay cutting out causing the "blubbering". although it's unusual it can do that. i just went through an intermittant no start on my taurus that the dealer could not figure out after many times stranding my wife but later starting right up. 3 trips to the dealer (wouldn't do it then), i had to walk them thru diag. it the old fashion way (thinking). they keep tossing it back to me because it would start AND they had no code). i asked them to switch f.p. relay with another known good... guess what no problem since. sounds like you may have got it.

Add a Quart of Actetone to a half tank of fuel. It will lower your HC's big time. I did this trick this weekend on my 4Runner with a burnt valve and it lowered the HC's by almost 400 ppm on the retest.

i've heard of rubbing achol too, wonder if/what that can/will do internally.

I heard less is more when it comes to additives like acetone...like one to two ounces per 10 gallons. I think a whole quart would start melting stuff... it is a solvent.

PASS PASS PASS ...it took me three times, but I passed barely on the second idle test 285 ppm on HC. 300 is the max... I retarded the distributor and upped the idle to compensate. Runs like crap now...I will have to retime it again and enrich when I get home. Thanks again for all your help. I don’t know if this thread is going to be of any help to anyone having the same problem as I, but it was a good experience, learned a few things along the way and met a lot of great people.

Note: Keep that throttle body clean. The breather ( idle screw ) mine was all closed up with grim. I can hear it again. It makes like a turbo “Chirp” sound.

I like it...

Glad you got it through

Damn this is spooky...

I have been hunting down Fat/Rich running problem on my 75 1.8 that is in a 72 body. Fixed every frkin potential problem I could find with no luck. Documented in another thread.

This thread got me to thinking what I had done since getting the car in April of this year. Well damn I was carrying spare relays in the open slots in relay board from something I had read here at one time about it being a good place for spare relays.

So I removed all 4 of them and left them out since I do not have Rear Window Defrosh or a working Heater. The second relay back from firewall had to be pryed with screwdriver and appears melted around the edge. Is this the FP relay spot for a 72?

I start the car up and it hit 800 cold idle(has been a problem) purring. I WOT it a few times and there is no more smoke pouring out the tail pipe! I drive it to work today and it does not appear to use a drop of gas. I have been able to almost watch the needle move down constantly.

Is my rich problem solved? Was it really that easy?? I will see soon enough!! RCR this wkend...

Could it be the relay board was still wired up 72 style and the relay was causing some kind of shorting out?? I will leave that for those smarter than me.

Sorry to ramble...

JKP

Thats awesome...maybe not knowing what the hell you are doing like myself is thinking out of the box...you are right kinda spooky