i was pondering how the amplifier recieved the signal for the injector wires. some of the injectors seem out of sync. Some pulse faster, slower, louder, and quieter than others.

got to looking around and found that my pickup coil wires were like rubberbands. they shared none of the characteristics of copper wire. lol

anyone think this could affect my injector signal?

im replacing the wires as we speak, but should i just buy a new coil instead?

 

the rate at which this stupid thing consumes fuel amazes me. 5 gallons gone. Xp

 

The wires from the pick up out of the distributor are a rubbery feeling thing. I believe that is due to the wire content being "stainless"??.

Mine were replaced with copper, soldered inside the distributor (that bit was fun), and RTV replaces the silly casing grommet.

The ECU in the boot gets an ignition pulse signal via that infamous shielded wire from the ign amp, that is used to keep the fuel pump circuit active, and the injection circuit active. Then the resistor pack ( as we call it) up behind the RH headlight does the injection powering.

If you got noisy injectors, that may be dud injectors, or the large rubber insulators (up under the clamp) have gone hard. HE injectors in general are quiet in the big scheme of things. PreHE are noisy suckers.

Excess fuel is a myriad of items, and injector ON time is the root culprit, caused by that myriad. The list of items is long, and I seem to remember you have been on this for some time, but lost track of all the threads.

"5 gallons so far" is a tad vague, and may be fine just running in the shop for a few hours??. I had a 5 litre container that mine was sucking out of when I was doing much rebuilding, and testing of my work as I went, and I was amazed at how quick it went down. Just saying.

 

running in the shop for half an hour total run time.

 

In short, NO.

The injectors are fired in groups of 3.

have you verified the wiring yet at the ECU?

How about compression and leak down?

 

yes. dont you read any of my posts? i verified the ****ing wiring man.

yes i know theyre fired in groups of 3. i spent 2 months under the bonnet rewiring it.

 

I would venture a guess that if the pickup coil were bad, you'd either have no signal at all, or very little throughout all the cylinders. It wouldn't be uneven.

Grant is the man to listen to when it comes to these engines. He's a genius!
I recall you said you found "green" corrosion inside your insulated wire and were going to cut it back more? How far did you go? I had to go all the way to the fender with mine to find any decent wire.

 

my signal wire wasnt bad. it wasnt even really corroded. it just looked a little sea sick i.e. a little green.

 

Well here's the thing...if it's turning green, then moisture has gotten inside it through a crack and is working through the wire. Any green (corrosion) will cause increased resistance , thus interference with the signal. I've seen oxidation travel several feet through a wire, so check it carefully. If the wire feels stiff, cut it back. This little buggar of a wire caused me much grief!

 

Oh yeah, one more thing I wanted to ask. Remember awhile ago I told you to unplug the injector harness and start the car to clear it out? It would only run for maybe 30 seconds or so, but how did it run when you did that?

 

i didnt put a disconnect plug in it. i just wired it right into the fender.

 

OK, at the risk of getting yelled/sworn at I will continue to answer until I feel I am fighting a brick wall.

I AM NOT A GENIUS, I am a grumpy OLD man with NO tolerence of anger towards cars, coz they are not responsible for the issues. That sits squarely with LOUSY maintenence for 20+ years (in the XJ-S case), and now you and me as enthusiasts MUST get it right, BUT, fair dinkum, it will not happen overnight, and may not be right the first time.

I am not going to go read all your posts on this saga, so if I repeat something you know/have done/ have rechecked. SO BE IT.

Um, I agree with 5 galls with 30 odd minutes of workshop running a tad excessive. I am surprised it ran for that long at all if it is actually overfueling that much, and that you are still breathing.

The resistor packs as such are super reliable. In the 7odd I have rewired from engine fires the resistor pack has always survived, as has the ECU itself.

The plastic multi pin plug in the bottom of the resistor pack is super UN-reliable, and spreading the pins with a razor blade (careful of the fingers) generally re-instates contact.

Cold start injectors (if you have them) dribble like a baby, and I ALWAYS remove them and plate the holes.

Again if I repeat what you already know, so be it.

The vac hose from the balance pipe TO the ECU can be an issue. It is a metal pipe under the car, so hoses each end, simple. It can get damaged, and the hoses can split. The hose in the boot "may" have a black plastic cylinder in it, which is a moisture trap, they crack.

One I did a long time ago, really tested my brain. It turned out to have little/no vac to the ECU. Overfuelled seriously bad. Found this by attaching a syringe to the ECU spigot via a hose, and applying vac, started the engine, and by operating the syringe, I was able to simulate RICH and LEAN fueling very easily, which eliminated the MAP sensor INSIDE the ECU. The NO vac was due to fire extinguisher foam down the hose at the front, due to the fire, and blocked the thing. Took 3 days to sort that one????.

Remember that the less vac the ECU sees the more fuel it supplies.

Inside the ECU is a small hose that goes from that vac spigot to the MAP sensor, and they do split, mine did, and the MAP sensors themselves can fail, but that is rare in my opinion.

 

Well said Grant. I have given up on trying to help this kid. Apparently I am supposed to keep track of all his posts. This issue has been talked about on several threads and 2 forums. The fuel injection on these cars is pretty simple and basic. With a good plan and logic you can fix them with relative ease. Compared to my day job these systems are more basic and fun to tinker with. Good luck.

 

Grant don't sell yourself short! You're a genius and if I lived closer I'd pay you for your services with the beverage of your choice!

 

thats an unusual way of looking at it i guess.

5 minutes at a time. it will run for 5 minutes and either

A: start surging like crazy until it dies
B: shut off with no warning

either scenario ends with it being impossible to start again until it cools for an hour or so.

i havent touched this connector yet, ill see what i can do, but all 12 injectors are operational. would a bad resistor connection allow them to continue to function?

dont have them

the ECU hose is fine. ive varified it with a both vacuum gauge and a vacuum pump. ive also played with the ECU map sensor using a vacuum pump to simulate idling vacuum. sometimes its the only way to even get it started. other times it makes absolutely no difference in the way it runs, especially once it gets near the 5 minute mark. you can play with vacuum simulation all you want and it has almost no effect on the way the car runs. since this is my 3rd ECU with no effect, im assuming the MAP in this, and the previous 2 ECUs is good.

my inner hose on both my old and new ECU are fine.

 

at this point, ive got some money saved up to either

A: make the V12 run
B: lump it

 

my ignition seems excellent btw.

also, my left bank is slightly quieter. im gonna unbolt the donwpipes and see if it improves. clogged cats would cause the vacuum to drop like a hammer. the pipes are awfully loud though. they seem too loud to be clogged. it would also explain the buildup and surging after 5 minutes of running.

 

I would think if the cat was bad on that side it would imped flow constantly, but I could be wrong. That would be a nice, simple fix if that's all it is.
But if the cylinders aren't firing like they're supposed to on that side, it would be quieter anyway.

 

i dont have a missfire.

in my experience, the exhaust gasses will build up until the motor chokes.

 

OK,

The 5 minutes (give or take) at a time prior to dying has me thinking of many things.

The running you describe is definately an overfuel issue. Now that can only come via the injectors/FPR's in your case.

The fuel pressure regulators can suck fuel, as you more than likely know, so I will assume that you have checked them, and/or replaced them with new, or a mechanical type on the LH side only.

YES, a bad resistor will/can cause injectors to stay ON.

A cross connection in the EFI loom could also cause this.

Retarded base timing also comes into mind.

Crossed wires from the CTS/TPS to and from the ECU pin out.

OK, so applying "false" vac to the ECU does little or nothing tells me that you are correct, all your ECU's are OK.

That tells me that the ingesting of fuel is beyond the control of the electronics. This may be:

Wrong injectors. By that I mean that the person who serviced them (if that was done) may have got it wrong, VERY doubtful, just saying. The HE injectors have a "beige" plastic infill, and the PreHE have "green" infill. Some aftermarket I have come across in HE engines are "blue" and flow waaaay too much fuel.

The FPR's are leaking (common).

The CTS is waaaaaay out of range at some points of its resistance (rare/commonish).

The TPS is just plain OFF (common).

As you said, maybe a blocked exhaust, which after reading a tad further I doubt, only due to your comment about equal noise from each pipe??.

Cam timing is out of whack (common), and/or the timing chain tensioner is broken (common now, and especially if some fool has wound the engine backwards).

If you are running it with the air cleaner backings removed (some do), have you put the bolts in place to block the holes mmm.

Fuel pressure is too high. Mine runs a mechanical FPR (LH side only), and I have it set at 29psi, and it is sweet. About 2 psi either side of that and I have engine issues, mainly on the + side. At 33psi it just "bogs down".