its only grounded at the amp end.

after fixing this wire, it still runs like ****. no change. after a 5 minute warm up it started surging, and promptly died.

Whats wrong with my V12? - YouTube

 

You mean the ground mesh is grounded by the amp? Or it attaches to the black wire? It should only be attached to the black wire which feeds back into the ECU.

 

Just watched the video...it sounds and looks like you've got a major vacuum leak somewhere! Are all 4 bolts in on each side that hold the airboxes on?

 

ive been in, on, and around this engine for over 2 months. there are no vacuum leaks to be had. and it didnt sound like that when i first started it up. it ran for about 5 minutes, and then something inside flipped a switch and it started surging just like that until it died.

it doesnt matter, as long as its grounded at one end or the other. but for the record, yes, its grounded to that black wire.


also, anyone wanting to know how loud my exhaust was? its so loud that the cameras mic cant even record it. its really, REALLY, loud.

 

Have you tried swapping in another amplifier?

Getting back to the vac leak - I've asked in a couple different threads here...have you taken care of all the vacuum stuff underneath the passenger's manifold? I know your air pump is gone - is everything blocked off? Is everything routed to the correct ports? If something's on the "off-idle" port instead of the manifold port or something, that'll do it. How are the air injection ports blocked off in the manifolds with the air pump rail gone? All that stuff is controlled or affected by temperature, or a timer that may make it seem like temperature.

I think you pulled the dizzy when you cleaned out your vee - what kind of shape were the wires to the pickup in? On both of mine they were horrible, worse than any other single piece of wire on the car.

Checked fuel pressure yet?

Does it die at idle or just when you open the throttle? I know it idles poorly but does it idle at all?

 

That surging wasn't you working the throttle? It was doing that on its' own?

Your idle is way too high and bouncing off the ECU's idle rev limiter (or whatever you call it). AAV or massive vac leak, or possibly misadjustment on the throttle plates. What did you set your throttle plate gap to?

 

i dont have any leaks. yes ive taken car of the stuff under the passenger manifold. the air injection ports are blocked off by threaded torx bolts.

the dizzy wires seem to be ok. theyre kind of rubbery, but thats about it.

i dont know what you mean by off idle ports.

 

We seem to be posting on top of each other. Check my post above about your idle speed.

On the TBs, certain ports are positioned very precisely at the very edge of the throttle plate, just when it breaks open. Externally these ports will look like they're in the "same place" as other manifold ports on the TB but aren't. If a vac line was put back on the wrong port you could have issues.

 

that surging was all on its own. when i gave it throttle and the vac went to 0, that was me.

which vacuum ports are yours connected to?

 

if what you say about the limiter is true, then it should go away if i turn the TPS, but not the throttle valves.

ive also got my AAV disconnected. idle is set with the throttle plates.

 

How did it run during that first 5 min?

 

it idled ok but wouldnt pull enough vacuum to mix its own fuel. i had to put a vacuum load on the ECU baffles to trim fuel correctly. it was somewhat responsive with minimal backfires. seemed a little leaner than usual.

 

I seem to remember a "fuel timer" on these engines that adjusts mixture as car warms up. I'll have to look it up.

 

You need to set this car up as designed. You have a lot of things not correct. Get a hose for the AAV and connect that back up. Then set the throttle plates properly. Connect the MAP line. Plumb the vacuum hoses as original or block them off except for fuel pressure regulators. Then set the timing according to specs.

In the mean time you need to verify your wiring repairs with a DVOM from the ECU connector.

Verify coolant temp sensor reading at the ECU connector.

When at operating temp or close to it measure the O2 sensor volts.

Do you have a spark tester? If not use an old spark plug and check that spark is getting to each spark plug when it is running. Do one cylinder at a time. Shut off, swap plug, restart and see nice spark each time.

Set TPS voltage to proper setting.

This is a fairly simple FI system. It uses MAP, TPS and CTS to determine fueling. Air temp, O2 sensors are used to trim the fuel.

The system fuel mapping is based on proper fuel pressure and a properly functioning ignition system(all 12 cylinders firing, correct firing order, timing).

You said you have no vacuum leaks. Have you checked the intake gaskets for leaking not just hoses? Once you get AAV and throttle plates set properly you will know for sure. A vacuum leak on these older FI systems will cause a high idle that you can't reduce with the AAV.

If this was my car I would do this and in this order:

1. ECU wiring harness checking. Use a DVOM to check that every wire is connected to correct place on the other end. It is time consuming but only way to be 100% sure is to do it.

2. A compression test and leak down test. Need to make sure you have an engine that can actually run properly.

3. Fuel pressure test. Jump the fuel pump relay. If it is at spec then go to the next step.

4. Throttle plate adjustment and throttle linkage adjustment

5. TPS adjustment

6. Connect all vacuum hoses to proper ports. Including distributer.

7. Recheck firing order one last time then start engine and set timing with light

8. Make sure all 12 cylinders are firing.

Once you do all this report back. Until then you have some work to do.

Once all the basics are done then and only then are you really ready to do more diagnosis.

 

You'll have to follow the vac hose digram to see what lines go to what ports, if yours is MIA they're online, just google it.

Your throttle plates should be .002" from closing and are sensitive to being unbalanced...can you rig up anything from the busted hose, even temporarily, to allow you to set your throttle plates correctly?

Jamey, you mean internal to the ECU? The only other timers are the 45sec or 15 min, then the thermal vac valve on the pass. side, and the CTS. As far as I can remember those are the only external time or temp inputs. 45-sec timer shouldn't do anything on his car since his air pump's been removed, unless someone miswired it back into something other than the SAV.

 

I remember reading about them, but I don't recall the details. The reason I wondered about a timer is because the car ran for 5 min, then died.

 

i can barely get it started once, let alone 12 times in a row. itll be so flooded by then.

ive done 90% of the things on your list. i havent checked the wires one by one, and i havent done a compressoin test. that is all.

 

The fuel timer enriches the mixture for 15 minutes if the coolant temp is below about 45°C. To disable it, very good idea, remove the two wires from the temp switch set into the A bank rear water manifold (below the RHS intake manifold at the firewall end) and tape them off.

To be absolutely sure there are no vac leaks, block off the throttles completely, and see what happens when you start it.

Greg

 

I am a bit loathed to add anything but I will anyway. I am aware There is a lot of input here.

The v12 Has a closed throttle map in the ECU separate from the running map. This was for emissions and can make the engine hunt between about 900 and 1500rpm. Is this the symptom?

 

If it is the closed loop, all he has to do is pull the plug on the 2 pin in the trunk, right?