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Wed Oct 01, 2008 10:20 pm

MOCHABILL wrote: :o "drain and replace the brake fluid with D.O.T.-5"

Is this not compatable with older systems. Just wondering :?:

If you do a search, it will come up. It is compatible, even more so because it does not damage anything if you have a leak or spill some.

spoon wrote: Hey fellas long time no see! I was looking through Phil's FI manual and found this troubleshooting guide. The highlighted is happening to me.... still. Forty pages later. Any ideas?

Did you try what it suggested? What have you done? More information, please. :D

Thu Oct 02, 2008 9:16 am

architect_7 wrote: spoon wrote: Hey fellas long time no see! I was looking through Phil's FI manual and found this troubleshooting guide. The highlighted is happening to me.... still. Forty pages later. Any ideas?

Did you try what it suggested? What have you done? More information, please. :D

I have checked for stuck injectors. One injector lets a drip go every 20-30 seconds or so, none stuck. Also, this issue started happening out of the blue. I didn't change around the injector connections/windings, so it's almost impossible for them to be in the wrong order. How would I make absolutely sure they are in the right order? Could the injectors not be stuck, but in some other way be faulty? What about testing the ECU? I've never tried that.

Thu Oct 02, 2008 9:22 am

spoon wrote:

I have checked for stuck injectors. One injector lets a drip go every 20-30 seconds or so, none stuck. Also, this issue started happening out of the blue. I didn't change around the injector connections/windings, so it's almost impossible for them to be in the wrong order. How would I make absolutely sure they are in the right order? Could the injectors not be stuck, but in some other way be faulty? What about testing the ECU? I've never tried that.

If I remember right, the connectors that are grey and black. 1 is black and 2 is greay but I don't know for sure about the 3 and 4

Thu Oct 02, 2008 10:14 am

Black sleeved injector wires go to the "front" injectors (#1 and #3). Grey to the rears (#2 and #4)

Thu Oct 02, 2008 12:03 pm

I have the grey injector boots going to the rear-most injectors, per Bentley. They've always been like that.

In the past hour, I swapped known good injectors from the 914 into my square. Same issue, zero improvement. The engine starts right up and doesn't hesitate. Idle speed is correct, it's just running rough and blowing grey/white smelly smoke. I don't have a noid light, but I am fairly sure that each injector IS firing (when I pull each injector wire, one injector wire at a time, the idle fluctuates)... now whether or not it is firing correctly, I am not sure.

Is there a way to test the ECU? Is it possible at all that I have a damaged ECU?

Thu Oct 02, 2008 12:20 pm

I don't think you've really eliminated your injectors/fuel pump until you actually WATCHED them ALL spray gas.

Thu Oct 02, 2008 1:22 pm

Low pressure or clogged nozzles interfere with a good cone-shaped, fine spray pattern. This can make a car appear to be running rich, because the gas burns poorly, leaving unburned fuel in the exhaust. It smells like it's rich, but runs like it's not getting enough gas (which it isn't). Confusing if you don't know this, and as posted, yuo have to see the pattern to know.

Thu Oct 02, 2008 2:54 pm

I just hooked up a pressure gage and confirmed that I have average 26-30psi of fuel pressure. When plugging various vacuum hoses the fuel pressure dips to the low 20's but then quickly rises to around 28psi. Like I said earlier, I just swapped in FOUR known working injectors, which yielded no improvement. I have enough gas in my oil to know that we're getting gas, but what's the best way to observe the injector actually spraying? Do I absolutely have to perform this step?

Thu Oct 02, 2008 2:58 pm

26psi is low enough to cause your symptoms. At low 20s it is surprising it would even run! Gas pressure should not change when you change vacuum lines on a D-jet system (the K-jet changes fuel pressure based on vacuum, but not the T3 system).

Suspect gas line pinching, clogged filter, faulty pressure regulator, failing overpressure valve in pump...

Thu Oct 02, 2008 4:13 pm

Buff of black smoke and dead. Outta gas. No wonder the pressure was fluctuating, not only that but a few seconds before she died the pressure bled to 0.

Anyways, she's got a full tank of gas now and started right up, initially running @ 26psi. I have her now turned up to 30psi. The pressure looks great and is not changing in the least. What's next?

Thu Oct 02, 2008 5:09 pm

spoon wrote: Buff of black smoke and dead. Outta gas. No wonder the pressure was fluctuating, not only that but a few seconds before she died the pressure bled to 0.

Anyways, she's got a full tank of gas now and started right up, initially running @ 26psi. I have her now turned up to 30psi. The pressure looks great and is not changing in the least. What's next?

I am skeptical of Type 4 injectors do to the size. Are they green tipped?

I would change the filter after running out of gas. Might have gotten a good dose of junk in it. I was told to, and it helped running.

Also, is the cooling system in proper order? Valves set right? Timing correct?

Thu Oct 02, 2008 10:02 pm

architect_7 wrote: spoon wrote: Buff of black smoke and dead. Outta gas. No wonder the pressure was fluctuating, not only that but a few seconds before she died the pressure bled to 0.

Anyways, she's got a full tank of gas now and started right up, initially running @ 26psi. I have her now turned up to 30psi. The pressure looks great and is not changing in the least. What's next?

I am skeptical of Type 4 injectors do to the size. Are they green tipped?

I would change the filter after running out of gas. Might have gotten a good dose of junk in it. I was told to, and it helped running.

Also, is the cooling system in proper order? Valves set right? Timing correct?

type 4 injectors should be ok for testing purposes if they're from the D jet 1.7 era of T4's.

Fri Oct 03, 2008 9:28 am

My original injectors were yellow w/ yellow tips and yellow w/ black tips. The injectors out of the (Porsche) 914 are identical in size and color. My injectors had a Bosch model number 0 280 150 007. The Porsche injectors had a Bosch model number 0 280 150 005. I only swapped these injectors because I knew for sure that they were good. Now that they are in my square, there has been neither an improvement nor a decline in performance. Still emitting unburned fuel out of the tailpipe and into my oil.

Fri Oct 03, 2008 9:30 am

No, T-4 injectors are wrong. They have a larger orifice. This system works on constant pressure and varies the amount of time the injectors are open. So, with a larger orifice, and same amount of time of being open, you will get more fuel, which equals richer mixture.

Fri Oct 03, 2008 9:50 am

The troubleshooting manual indicated bad injector windings, so I swapped in the known good injectors. Although there has been no improvement with these good injectors, since they flow more it is quite possible I could be recreating this problem with the Porsche injectors.

Anyone care to clue me in on the next step?

Fri Oct 03, 2008 1:58 pm

Also, just to key in on Phil's point about the "cone shaped" spray pattern, is it possible that all injectors become clogged at the same time, causing this issue? As stated earlier, I have a pressure gage hooked up as we speak and I have an uber consistent 30psi of fuel pressure reaching the injectors. Is there something deep within this system that is causing this? Can a bad ECU be causing the injectors to not fire appropriately?

What about the fuel injection contact points within the distributor? About 40 some-odd pages ago I took the dizzy apart and posted a picture of the contacts. I cleaned everything up and put it all back together, and had zero improvement afterward.

Is there something mechanical within the engine that could be causing this? (valves, piston rings, etc)

I just ran the engine for about 20 minutes straight, unplugging and plugging every conceivable connection, vacuum and electrical, and still can't find a clue as to what is causing this problem. Spark is getting to all plugs, orange colored. The exhaust is still smelly with a little bit of grey smoke.

Fri Oct 03, 2008 2:02 pm

Maybe you need to adjust your MAPS like mad97321 was telling us all yesterday?

Fri Oct 03, 2008 3:14 pm

Mike Fisher wrote: Maybe you need to adjust your MAPS like mad97321 was telling us all yesterday?

Okay. Just unbolted the ol' MAPS and had a looksie. The hose that connected the MAPS to the intake air distributor was a bit corroded at one end. The hose seemed to slip off quite easily from both nipples, especially the one under teh IAD. I cleaned her up and affixed a new, tighter fitting hose. I checked if she holds suction and she does, without any hissing.

I remounted the MAPS and the amount of white smoke seems to have declined. During idle, smoke is barely noticeable, yet the motor is still running rough. When revving, black smoke is now appearing from the tailpipes.

Also, here's a rundown on what happens when I remove...

Spark plug wire:
#1: Drop in RPM
#2: Drop in RPM
#3: Drop in RPM
#4: RPMs seem to stay the same, maybe

Injector lead:
#1: Drop in RPM
#2: Drop in RPM
#3: Drop in RPM
#4: RPMs seem to stay the same, maybe

Fri Oct 03, 2008 3:37 pm

spoon wrote: Mike Fisher wrote: Maybe you need to adjust your MAPS like mad97321 was telling us all yesterday?

Okay. Just unbolted the ol' MAPS and had a looksie. The hose that connected the MAPS to the intake air distributor was a bit corroded at one end. The hose seemed to slip off quite easily from both nipples, especially the one under teh IAD. I cleaned her up and affixed a new, tighter fitting hose. I checked if she holds suction and she does, without any hissing.

I remounted the MAPS and the amount of white smoke seems to have declined. During idle, smoke is barely noticeable, yet the motor is still running rough. When revving, black smoke is now appearing from the tailpipes.

Also, here's a rundown on what happens when I remove...

Spark plug wire:
#1: Drop in RPM
#2: Drop in RPM
#3: Drop in RPM
#4: RPMs seem to stay the same, maybe

Injector lead:
#1: Drop in RPM
#2: Drop in RPM
#3: Drop in RPM
#4: RPMs seem to stay the same, maybe

This is exactly what I had trouble with. Replace number four injector, and be careful of its tip. I had one where I just bumped the tip, and because of this, the needle valve did not fully close, which caused the problem you are having. You can carefully press on the needle, and it should move about a millimeter. You can do this installed, and see it squirt some.

Fri Oct 03, 2008 4:28 pm

architect_7 wrote: spoon wrote: Mike Fisher wrote: Maybe you need to adjust your MAPS like mad97321 was telling us all yesterday?

Okay. Just unbolted the ol' MAPS and had a looksie. The hose that connected the MAPS to the intake air distributor was a bit corroded at one end. The hose seemed to slip off quite easily from both nipples, especially the one under teh IAD. I cleaned her up and affixed a new, tighter fitting hose. I checked if she holds suction and she does, without any hissing.

I remounted the MAPS and the amount of white smoke seems to have declined. During idle, smoke is barely noticeable, yet the motor is still running rough. When revving, black smoke is now appearing from the tailpipes.

Also, here's a rundown on what happens when I remove...

Spark plug wire:
#1: Drop in RPM
#2: Drop in RPM
#3: Drop in RPM
#4: RPMs seem to stay the same, maybe

Injector lead:
#1: Drop in RPM
#2: Drop in RPM
#3: Drop in RPM
#4: RPMs seem to stay the same, maybe

This is exactly what I had trouble with. Replace number four injector, and be careful of its tip. I had one where I just bumped the tip, and because of this, the needle valve did not fully close, which caused the problem you are having. You can carefully press on the needle, and it should move about a millimeter. You can do this installed, and see it squirt some.

With the 3/4 injector pair removed from the head (but still connected to fuel lines) they are both holding fuel. No drops. Both needles are not protruding from the tip, they are flush with the tip. I took a paperclip and with the fuel system pressurized, and pressed both needles in, one at a time, and got what looked to be a cone-shaped spray. They made a "psst" sound. The number 4 injector is black-tipped, while the number 3 is yellow-tipped. How can I make positively sure that the number 4 injector is bad?

Although there is no more white smoke coming from the tailpipe, is it possible that my sparkplugs are now FOULED due to all of the troubleshooting?