Help, please. Kapow... now won't run... Options

[Cuda911]

Hey guys,

Assistance requested please:

I drove the car fine this morning. This afternoon when I started it, there was a loud "bang" almost like a backfire sound, then the motor died and wouldn't restart.

Upon inspection I found that the hose from the oil filler (see attached pic) had completely popped off, on both sides.

I reattached it and added some hose clamps. Now the car starts, but idles VERY roughly and when I press the gas the revs don't increase at all.. the car just stalls.

So, what should I be looking for here?

1974 1.8, FI.

Thanks!

[914Sixer]

Backfire may have killed the AFC unit.

[rosenfe]

i was told not to clamp those hoses,as backfire will blow them off,if clamped more serious damage may happen

[Cuda911]

OK, thanks for the tips. I'll take the clamps off.

Mugs, got anther project for ya.

[Dave_Darling]

Pull the air flow meter off the intake and see if the flap in it opens and closes smoothly. If not, you've found your problem.

--DD

[Cuda911]

Will do, thanks, Dave.

Air flow meter damage does sound likely. I tried starting it again later in the day and it started right up. But the idle kept jumping all over the place... running rich, then lean then rich, then lean...

I found the following on AutoAtlanta's site:

"The 1.8 air flow meter often fails when a cold engine lean backfires, warping the sensor flap. this warped flap sticks in the bore causing a rich mixture and an idle that goes away as the engine warms. replacement is the only solution, however it is important to cure the lean running engine that initially caused the problem, change the gas flooded oil and never again depress the accelerator pedal when starting a cold engine."

Hmm..... If I don't depress the accelerator pedal to the floor when starting, not a chance it will start.

Here's a pretty darn basic question for you guys.... How do you start your car? Press the pedal to the floor and turn key? Press pedal part way? Don't press at all?

[Big Len]

Got the same 1.8.

I don't touch the pedal at all, whether warm or cold.

[bigkensteele]

You may want to PM Timothy_nd28. He is the L-jet guru.

[Nine_14]

Compression Test done ? Maybe too much pressure in the crankcase, caused by damaged piston rings or pistons by itself.

All 4 cylinders running ? Check it by removing the spark plug connectors one after another.

[Cuda911]

I think I'll take it over to MRD and have Mulligan take a look. He'll get it sorted out way faster than my mucking around. I'll keep you guys posted.

Mike: Called your number this morning and got a message saying it's not in service. Pay your phone bill.

[timothy_nd28]

As to what the others have already posted, your air flow meter is junk. This happened due to a backfire, which then caused the flap within the airflow meter to warp. With the airflow meter flap not moving correctly, your fuel to air ratios are all out of wack. So, this too is my diagnosis of why your car now runs shitty. To take this cause and effect scenario to the next stage, we need to figure out why your car back fired to begin with, which is usually caused by vacuum leaks.
I personally know this game all too well. Back in high school, I had a huge vacuum leak due to a big crack on that rubber S boot thing and was waiting for AA to mail me a good used one. Months went by, so I made due by taping this crack with many rolls of electrical tape. I went thru 3 perfectly good air flow meters (on my dads credit card (IMG:style_emoticons/default/happy11.gif) ) with this taped up S boot. Tweeks made some good money off of me during those years, till I finally got a better S boot.

[Cuda911]

Jeeez... never would have guessed that one backfire could blow that air flow meter out. Live and learn.

I spoke to Mulligan this morning and will get the car over to his shop probably on Thursday.

Assuming it's the air flow meter, how tough is it to find one, and at what price? I understand that new ones are no longer available?

[bigkensteele]

Rich at High Performance House probably has an AFM for you. BTW, '74 is different from '75 as the number of pins is different. Count your pins and make sure you get the right one.

http://www.highperformancehouse.com/

[colingreene]

Sorry to hear about the damage 3M

[Cuda911]

OK, thanks guys.

I'm still keeping fingers crossed that I just missed another popped hose somewhere. I'll poke around some more, and if I don't find anything the Honorable Mugs Mulligan will take care of things.

[914Sixer]

Check over on theSamba.com. The units turn on up because the VW bus used them from 76 on.

[Cuda911]

Thanks for the sourcing tips. Bruce Stone may also have one.

Hmmmm..... if it's so easy to damage these units, maybe it's a good idea to buy an extra to keep as a spare? Do any of you do that?