1971 914-4 Frankenstein, w/ 912E 2.0 L-Jet FI? Options

[timothy_nd28]

Good, applying power straight to the coil with the engine not running is a good way to ruin the points or pointless module inside the distributor.

Go ahead and investigate the cylinder head temperature sensor, meanwhile I'll see if I can find a pin out for your ECU

[timothy_nd28]

This is a true Frankenstein!

Pin 12 should not go to the throttle switch. Pin 12 is reserved for the altitude compensation device. This holds true atleast up till 1978 California Vanagons, your ECU is from a 77 Vanagon.

Now, there seems to be 4 different variations of ECU's for the 77 Vanagon, and I'm not exactly clear what the real difference between them are. From what I gather, some had manual transmission ECU's while others had automatic transmission ECU's. I believe some where California ECU's. Your year ECU seems to be the threshold of when they started to not use the throttle valve (WOT) switch. You may have a mismatched wiring harness for the ECU you have. Again, not 100% sure of this.

Either way, the throttle switch is not causing your issue. We need to see some resistance on pin 13 at the ECU connector. Also, do you have a 6 or 7 pin air flow meter

[mikesjunk]

7 pin AFM

Here's a photo of the temp sender. This doesn't look like it's going to be fun to change. Anyone know what size that is as I'm guessing I'll need to slit a socket to get this out.

(IMG:http://www.914world.com/bbs2/uploads_offsite/www.mikesjunk.com-19423-1450996852.1.jpg)

There are only two wires on the throttle switch in the connector. Next trip out I'll see which pins on the throttle switch they are on and where the other one goes.

I need a computer in the shop! (IMG:style_emoticons/default/smile.gif) But I guess I'm doing the pre-Christmas dinner workout.

[mikesjunk]

Throttle Switch

Ok so here's what the pigtail to the throttle switch looks like.

(IMG:http://www.914world.com/bbs2/uploads_offsite/www.mikesjunk.com-19423-1450999899.1.jpg)

This has obviously been subject to POs. So the two wires that show looping back, they go no where. I ended up splitting this open since I couldn't get them to ring out.

So here it is on the switch. The two wires highlighted in yellow both ring out back to #12 in the ECU connector. The other two go no where.

(IMG:http://www.914world.com/bbs2/uploads_offsite/www.mikesjunk.com-19423-1450999899.2.jpg)

[JeffBowlsby]

I should go back a reread this whole thread...bizzarro...what else can be said? Looks like you have a 912E engine or at least some of its injection system, with a 5-pole D-Jet TPS connector morphed into it for who knows what purpose. Here is a photo of a 912E engine/fuel injection if it of any assistance. I have more photos if you need them.

I also have downloadable D-Jet and L-Jet Fuel Injection manuals (including 912E) here:

http://bowlsby.net/914/Classic/TechNotebook.htm

914 Ignition and FI wiring harness diagrams may be useful in wringing this harness out:

http://bowlsby.net/914/WiringHarnesses/

[mikesjunk]

Thanks Jeff, I've already been on your site a time or two.

Yes this is quite the challenge. The worst is that at one time it ran. Then it's been in the garage for a number of years having been worked on by several different people. I have no idea what parts it came with and what ones were put on it attempting to make it run. So who knows if it ran in its current configuration, but my sister thought I needed a challenge.

I have a Polaris ATV next to it in many pieces that I'm not sure which one has been the most challenging. (IMG:style_emoticons/default/smile.gif)

[mikesjunk]

Hope everyone has been having a good holiday's. Bumping this back up with some updates.

Bought a cheap socket at Harbor Freight and cut a hole in it so I could remove the cylinder head temp sensor. Got it out and still it has 0 ohms and no ring on continuity. So I ordered a new cylinder head temp sensor. It came on Wednesday and guess what it also has 0 Ohms and does not ring on continuity. So this one is still a mystery. It was a Bosch sensor. Went ahead and installed it and I still have the same issue. Starts and then dies upon key release.

So I guess it could be my meter as its a cheap backup so on my shopping list is to replace my good meter that finally died after a couple of decades. But I'm not betting on this being the reason why the sensor doesn't have any Ohms.

[mikesjunk]

Note to self: Don't use a cheap meter for trouble shooting

So got a new meter and redid the results. I'm quite surprised at the difference in readings between the two meters. Well one's in the trash now. Same conditions, starts but dies when key is released.

(IMG:http://www.914world.com/bbs2/uploads_offsite/www.mikesjunk.com-19423-1451761882.1.jpg)

[Dave_Darling]

L-jet should use the dual relay to run the fuel pump. D-jet uses one of the round relays on the relay board, but it is triggered by the ECU specifically. Yours has obviously been rewired somehow, possibly to switched power?

L-jet should only have the non-adjustable fuel pressure regulator that has a vacuum line running to it. D-jet should only have the adjustable fuel pressure regulator with no vacuum line on it. Running both is not going to give you very good results, I think. Likely the pressure will wind up being limited to the lower of what the two regs are set to.

--DD

[mikesjunk]

Ok for the fuel pressure regulator, if I just have the vacuum one in the line alone I'm getting 75psi. I applied vacuum with a mityvac to the port and it didn't change the pressure. So I'm guessing it's not working so for now I'll probably just have the screw one in the line as it's giving me 35psi. Something on the list to fix/replace.

So I ran a wire from the relay to the pump today. And so now I leaning towards the dual relay. I'm not getting any voltage from the fuel pump output at any time. I even jumped 12v to 86a which I believe should pull the coil in for 12V out to fuel pump. Doing this did make the cold start valve click so I know part of it was working.

But I'm sure its not lack of fuel causing my issue as previously I jumped the pump out and was maintaining 35psi at all times. So just another item to the list for hopefully once it's running that needs worked out.

I'm off to find the dual relay test process I saw somewhere as there may be some other things in there that are keeping it from staying running.

[timothy_nd28]

Yep, no need with a dual regulator setup. If the Ljet style regulator is broken then you should replace it and remove the Djet style one.

You mentioned with your current setup up that you have 35 psi of fuel pressure. When you release the key and the engine stalls, is the fuel pressure still at 35 psi?

I'm glad you got a better meter but 5k ohms is way out of range for the CHT sensor and the temp sensor inside the AFM. What is the current outside temperature? Try re-measuring the old CHT sensor while inside a warm house, I'm curious to what that reads.

IF the fuel pressure is holding steady regardless with engine running or not, then we would need to inject 12vdc straight into the Ljet computer. It is possible since the dual relay has been rewired, that it is dropping power to pin 10 at the ECU when the key is released. So to temporarily bypass this, jump pin 88a at the dual relay to the positive battery post.

[mikesjunk]

I'm cheap so my shop is at 45F and I have good coveralls. (IMG:style_emoticons/default/smile.gif) It's been in the high 20s to low 30s around here. I thought I saw somewhere the reading was supposed to be 7k at 16F. Today the reading was 3.7k and I put a heat gun down blowing on the cylinder head sensor. It dropped to 2.88k in about 30-45 seconds.

I put the screw fuel regulator in the line by itself and it holds 35psi at all times. No needle movement at all.

On the relay at key on I'm getting 12v from the coil to 86c but 0V at both 88b and 88a so looks like this side is not working now. This is strange since when I was pinning out the harness in chart above I was getting 12 volts at 10 at all times. Hmmm.

So I got an alligator clip, pulled the wires from the relay for both 88b and 88a and clipped them to the battery. Added the fuel pump to the battery and tried. Same thing starts and then dies. Maybe my imagination but may have rotated a few more times prior to dying. I did have a meter on the alligator clip and it would drop to 11.8ish during cranking.

[timothy_nd28]

K, does it stay running if you spray starting fluid in the intake?
With the low temperatures, the car could be running off the 5th injector. It would be good to do a spray test on each injector to verify they are spraying right.

[mikesjunk]

Well Tim you might be on to something there. So jumpered fuel pump and jumpered 88a/b and a can of ether. So I was able to keep it running a few more spins with ether. So looks like I'll be pulling fuel injectors and probably going to need seals as most things on this car are old and rotten.


Since this is a Frankenstein were there different fuel injectors for the different years/models? Probably just need to send them off but hate to spend money on ones that don't really belong to the car.

[JeffBowlsby]

Lots of different injectors - dependent on the ECU and other sensors, specific to each vehicle. If you are putting together a correct 1.7L FI system here is a guide:

[timothy_nd28]

The last test was to help isolate a fuel delivery vs a spark related issue. I was hoping you could of kept the engine running indefinitely with the ether, being that you can't leads me to think you may have a spark related issue. The Ljet ECU uses ground pulses from the points in the distributor to generate a injector firing pattern.

I'm not condemning your fuel injectors. Knowing the spray pattern is good info to help piece this puzzle back together. In addition, the injectors are specific to the ECU, which yours is a 77 or 78 ECU. I wonder if the injectors you have are even compatible with that VW bus ECU?

Remove each fuel injector from the intake but leave each fuel injector connected to the fuel rail. Also, try to post the part number stamped on each fuel injector. Then get your fuel pump to activate the way you have been in previous tests. Once you are holding 35 psi of fuel pressure, remove the ECU connector and jump pin 14 to the negative battery post. You should hear a click and fuel spray out from one injector. It would be good to have a catch can under each injector. After pin 14, jump pin 15 then 32 and 33 the same way. Be observant of the spray patterns and report back what you see.
**Forgot to mention that you will need to keep 88a and 88b jumpered to the positive battery post while performing this spray pattern test.

[mikesjunk]

And the Frankenstein continues. The injector numbers were 280 150 116 so it's part Beetle also.

So the test was 75% good. (IMG:style_emoticons/default/smile.gif) Three of the four injectors seemed to work and had decent spray pattern. One only clicked and dribbled. The list of things to fix keeps growing.

So the dilemma....what to do with injectors.

[timothy_nd28]

Crazy stuff! (IMG:style_emoticons/default/blink.gif)

Did you say that this frankenstein FI setup was built on a 1.7l block? If so, how did they cap the cylinder head vents?

[mikesjunk]

Someone on the other post said it looked like a 1.7 from the spark plugs. So where would I look for the cylinder head vents?

Block part number was W01.....so I think that's 1970.

What's crazy is that I was told it was running in this condition. I know when she bought it was running. But I'm guessing parts were swapped over the years and many garages it was in. From the file I got I see a receipt for a dual relay in 2012 and the fuse panel but nothing else.

I found a craigslist for a 1973 complete FI that's looking more appealing. I would rather troubleshoot something matching versus this mismatch. Plus I have a feeler out in this forum's classifieds.

Doesn't make sense to send out injectors since they don't match but hate to buy new ones as what do I buy?

[Al Meredith]

I have owned 3 912Es and now have #265 But I converted it to carbs. Before that I know that the duel relay is very sensitive , Mine was dropping out when I went over RR tracks. DR. 914 told me that they get old and they tend to drop out with a shock. TIM IS ON TO SOMETHING The 1.8L and 2.0 912E FI system is VERY sensitive to vacuum . If you remove the dip stick the engine will stall. I've been there. Look on page 24 of the AA catalog and you will find a 1.8 oil cap seal. If the oil cap leaks air it will stall.