'75 L-Jet running rich "Smog Test Blues", OK I should of started this thread 3 days ago Options

[tabs914]

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... (IMG:style_emoticons/default/blink.gif)

[orange914]

. I started out just running rich. So I made a very small adjustment to the AFM to lean it out.
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.

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

[tabs914]

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... (IMG:style_emoticons/default/pray.gif)

[Cap'n Krusty]

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

[tabs914]

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...

[zonedoubt]

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.

[ClayPerrine]

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.

[tabs914]

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.

How much do you want for the AFM + Shipping?

[zonedoubt]

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.

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.

[bfrymire]

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.

How much do you want for the AFM + Shipping?

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

[tabs914]

I will check it out. Thanks...

[Brando]

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.

[ClayPerrine]

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.

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.

[Cap'n Krusty]

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.

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

[tabs914]

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!!! (IMG:style_emoticons/default/piratenanner.gif)

[Brando]

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.

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!!! (IMG:style_emoticons/default/piratenanner.gif)

[tabs914]

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?

[Brando]

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?

[tabs914]

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

[scotty]

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?

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! (IMG:style_emoticons/default/piratenanner.gif)