Video of my 1.8 dying...Can anybody guess why?, Looks like it was a poorly connected double relay!!! Options

[orthobiz]

Thanks for the advice. I have lots to think about!
The Tangerine headers just won't work for me and my desire to have a quiet car, power be damned! LOL

Paul

--DD

[Rob-O]

If you decide to put the L-Jet on the 2.0L, keep the 2.0L intake runners. The 2.0L runners have three holes that attach the runner to the head. The L-Jet 1.8L has 4 holes that attach the runner to the head.

If you look up L-Jet on Google, there is a great document out there that outlines what all the components do, how to check them, troubleshooting section, etc. It was written for the 912 version of L-Jet, but almost all of it applies to the 914.

Keep the L-Jet. Instead of just replacing parts, start checking them out. You should be able to narrow down the culprit pretty quickly based on the car dying when warmed up.

Since it sounds like it came on abruptly, instead of slowly over a matter of days, weeks, months. I'd say it is a component that failed or is failing versus a vacuum leak. With that in mind, have you checked the AAR (Auxiliary Air Regulator)? I didn't watch your videos, but you have TWO systems at work when the engine is cold. The cold start valve (Whether it turns on or off on start is controlled by the thermo-time switch) and the AAR (has it's own internal heater). The cold start valve injects more fuel into the plenum at cold start. The thermo-time switch detects that the outside air is cold and then (if I understand the theory correctly) the FI brain enables the cold start valve for a matter of time (something like 8 seconds total). The AAR on the other hand will stay open until the engine warms up enough to warm up the heater in the AAR. Once warm, the AAR eventually closes. The air that the AAR receives has been metered by the AFM (but not the TB) and so the amount of fuel will have been metered. But after the engine warms up, if the AAR doesn't close, I believe you'll run into a lean condition that could cause the engine to die.

Good news? The AAR can be cleaned fairly easily once you pull it off the engine.

More good news? You should be able to check AAR operation fairly easily by pulling the vacuum line from the AAR and capping it off at the plenum. If you do this, I would suggest unplugging the cold start valve as well so the engine isn't getting lots of extra fuel but no extra air at startup. It may make starting the engine a little more difficult initially, but once running you'll be able to identify if the problem lies with the AAR

[Rob-O]

Just remembered something else. Did you check the seal in the oil cap filler? Maybe a new one might help.

Yes. The red rubber seal was black and so hardened/brittle I had to cut it with tin snips. I replaced both seals. Every time I replaced a hose or the AFM rebuilt or injector seals I had hope it would run. I see there is love for the L-jet but I gotta tell you this vacuum sensitivity is making me nuts!

Paul

Where did you get the new red rubber seal??? I just posted earlier today that I am looking for one but having trouble finding a supplier that either carries them or has one in stock.

[Rob-O]

Should've known it was on Jeff's website...

http://www.bowlsby.net/914/Classic/zTN_Man08.pdf

[orthobiz]

Where did you get the new red rubber seal??? I just posted earlier today that I am looking for one but having trouble finding a supplier that either carries them or has one in stock.

I get a lot of small parts through Brad Mayeur at 914ltd. He knows my car so there's no guesswork on what part I am ordering. His prices are competitive.

Paul

[orthobiz]

The air that the AAR receives has been metered by the AFM (but not the TB) and so the amount of fuel will have been metered. But after the engine warms up, if the AAR doesn't close, I believe you'll run into a lean condition that could cause the engine to die.

I thought about the AAR but did not check it. The car is taking a trip to Brad's this Friday so I will not do further diagnostics...but I will talk to him about keeping the L-jet.

What's a TB?

Thanks for the detailed analysis!

Paul

[Rob-O]

The air that the AAR receives has been metered by the AFM (but not the TB) and so the amount of fuel will have been metered. But after the engine warms up, if the AAR doesn't close, I believe you'll run into a lean condition that could cause the engine to die.

I thought about the AAR but did not check it. The car is taking a trip to Brad's this Friday so I will not do further diagnostics...but I will talk to him about keeping the L-jet.

What's a TB?

Thanks for the detailed analysis!

Paul

TB=Throttle Body

Yup, knew about the trip but thought you might want to give it a shot before heading to Brad's place. Could help if you decide to sell the L-Jet. Complete known good condition versus had issues when pulled.

[orthobiz]

More good news? You should be able to check AAR operation fairly easily by pulling the vacuum line from the AAR and capping it off at the plenum. If you do this, I would suggest unplugging the cold start valve as well so the engine isn't getting lots of extra fuel but no extra air at startup. It may make starting the engine a little more difficult initially, but once running you'll be able to identify if the problem lies with the AAR

So if I plug off the AAR, the car shouldn't stall because it would be as if the AAR closed properly?

Paul

[timothy_nd28]

I just looked at the longer video and noticed the oil tower doesn't have a hose attached to it, was this capped?

[orthobiz]

If you mean the giant 21mm hose on the oil filler, it's there! Connected to the S-hose.
Actually, the only thing different about my setup is the absence of a charcoal canister.


Paul

[Rob-O]

More good news? You should be able to check AAR operation fairly easily by pulling the vacuum line from the AAR and capping it off at the plenum. If you do this, I would suggest unplugging the cold start valve as well so the engine isn't getting lots of extra fuel but no extra air at startup. It may make starting the engine a little more difficult initially, but once running you'll be able to identify if the problem lies with the AAR

So if I plug off the AAR, the car shouldn't stall because it would be as if the AAR closed properly?

Paul

Theoretically, yes. If that's where your issue lies.

[914Sixer]

I may have a canister if you need one.

[iankarr]

Hmmm. Came on abruptly. Stalls when warm. Fades under power. Backfiring...

Have you checked the ignition coil?

[orthobiz]

I may have a canister if you need one.

Thanks. I always wonder about how important the canister is; I've seen pics of other engine compartments without it...

Paul

[orthobiz]

Hmmm. Came on abruptly. Stalls when warm. Fades under power. Backfiring...

Have you checked the ignition coil?

No, but I may bring a new coil I have with me when I go to Brad's. Thanks for the idea!

Paul

[catsltd]

Edit: I added some video of my 1.8 engine's behavior. What you are seeing is about 2 minutes into the engine running from a cold start. I tried to capture a little of the shakiness of the engine as well. Wondering if anybody has a good idea of what's going on as I may want to sell the engine after the swap.

914 1.8 Stalling

Original Post:

So late last "season" (Porsche weather is May to November here in Michigan), my car stalled between shifts. Started up OK but conked out when warm. So...I discovered a disconnected hose and started a hose renewal project. After replacing every hose, the problem persisted. But along the way I had to replace the AFM as the car backfired and warped the flapping door. Still no success. Replaced the fuel injection seals, oil filler cap seals, still conks out after warm up. Contemplated a new brain and wiring harness and cylinder head temp sensor but have run out of patience.

To make a long story short, I've decided to go with a 2.0 and plan on dropping my car off at Brad Mayeur's next weekend. I've always wanted more power anyway.

Questions:

1. How much power am I losing by sticking with the stock 1974 exhaust system?

2. What to do with the 1.8? It ran strong before the problems developed, but the car is of unknown mileage. Seems like interest in these engines is, well, underwhelming. Brad said he has more than enough of these engines.

3. I'm sure he could get the 1.8 FI running on the 2.0, I know there are proponents of the L-Jet...Is that something worth pursuing or stick with the D-Jet?

Thanks,

Paul

BTW, I have a pristine orange 1.8 that is staying stock. This is for my red driver!

I might be interested in the motor,if you go with a 2.0.
Thanks Grant

[Chris H.]

Mine did that exact same thing. When I installed a Pertronix it went away completely. YMMV. FYI as long as the exhaust is a pre-'75 there isn't a ton of difference in the flow between 1.8 and 2.0. It's the later 75-76 cars that get choked by the single pipe vs dual pipes setup.

[orthobiz]

On the road to Brad's...updates soon!

Paul

[orthobiz]

So, went to Brad's. We went out for lunch, his mechanic Michael played with the DOUBLE
(DUAL?) RELAY and when we came back, the car was running like a top! So, I am putting off a new engine and will maybe put the money into a new paint job instead. In the meantime, I need a "new" engine harness and other odds and ends so I hope to pick the car up in a few weeks.

Paul

[r_towle]

Brad is not just a good mechanic but a great friend to the 914 community.
He could have sold you a new motor....