You have said that the injectors can be heard clicking when you plug the TPS into its chassis loom.

This indicates to me that something is supplying an earth to the injector circuit, and thus opening them, maybe holding them open, maybe not.

My suggestion now is to do a continuity test on that wire from pin 7 of the ECU plug to that terminal in the engine bay. If you got very good continuity, then the ECU is suspect to me.

I know you have changed it out with an unknown unit.

That year model MAY still be running the 6CU spec ECU, and they were trouble, mainly with the fuel pump circuit, but getting more frequent with the injector circuits as age creeps in. The 16CU spec (about late '87 here) is a direct plug and play ECU, and processes data about 5 times faster than the 6CU, and generally significantly more reliable all round, and is what all mine run.

I still reckon you got serious issues with all/any wiring in that engine bay, and it has been that way for a very long time.

 

Yes you are probably right.
It was actually the mutiplug for injector loom,that was making injectors click.
I'll check continuity on the #7 I already cleaned grounds and plugs so not much left.Maybe its time to try new ecu.
thanks

 

well,Opened ecu found a bridge between circuits burnt.so solderd it up and still no pulse on injectors.
found another mutiplug up at bulkhead.the signal coax wire from ecu comes throgh there among others.It was corroded with green crap so going to auto parts to get some abrasive paper to clean it up.
This is my last hope..
Ill let you know what happens
thanks

 

Ok I cleaned all multi plugs.I disconnected plug at ecu,with ign on checked #18 on plug there is 12.45v on coax wire from ign amp to ecu.My question is Should there be 12v on coax to ecu or 6.0v
Nowhear is the mystery,I have 2.6v on cts wire U/O comming out of ecu,but when I check at cts plug sensor I have 3.6v strange.
Here are readings at ecu ign on..ATS pin #21 R/U wire 3.4v Y/K wire 4.96v
CTS pin #5 U/O wire 3.4v Y/B wire 0.1v
TPS pin #7 y/w spiral to red wire on tps harness 0.34v closed throttle,wide open throttle 4.98v.Pin 19 y/b wire to yellow wire on tps harness 0.1v
pin #20 y/k wire to green on tps harness 4.96v

 

This is the last straw on this car,
If I check the wires comming out of ECU,that go to power resistor to make injectors pulse,while I have someone cranking eng will that tell me if its ECU thats bad?
Ok, Y (which is hold on) pins #30,12,29 and 11 going by schematic,looks like they go to ECU from power resister.
Then (X) (turn on) on A bank pins #32 and 14 with a tie in of 31 and 13 go straight to injec harness from Ecu.
The (X) (Turn on) on B bank pins # 27and 9 with tie in of 28 and 8 if I check wires Y # 30, 12,27 and 11 with test light,If they pulse while cranking eng that would mean ecu is good??
What do you think??Or is it the X side (turn on) to check for pulse.?

 

Have you thought about a carbs and crane ignition. I was going to go this route because it keeps it simple. I think most problems would be solve. I know of a guy with manifolds, 4 carbs and air boxes. Just a thought.
Im going 350 V8 myself. I think it would be more reliable and easier to increase performance. Not to mention lighten front end by hundreds of pounds.

 

A fully dressed for install 5.3 Jaguar V-12 is 680 lbs the average 350 Chevy is 600 to 650, can't see much of weight savings. Keep plugging along, you'll get her going and in the end it'll be worth the trouble.

http://www.gomog.com/allmorgan/engineweights.html


I know the last thing you want to do is spend more $$ but David Boger has an ECU on his site for a fair price. If I had a spare I'd ship it your way to do at least a test swap so that could be narrowed down...anyone here with a spare they want to temp donate??

http://shop.everydayxj.com/category_...show=10&page=3

 

I have seriously thought about a swap,and I appriciate the info BC, but at this point Im dedicated. lol.
I have to conquer this car.
and that would be great If I could get another ecu to compare that would be cool.
I appreciate the shout out JT..im going to check pulse comming out of power resister and will post results.
Thanks for responding..

 

Ok,Here is what I found.
I pulled inj 1A and 1B on front of eng,out to check if they spray or not.
I put a test light to the O/W wire comming from power resister,at junction of injector harnness.Turned on ign,and the front 1A injector sprayed,not sure about the rest in A bank but im assuming they did.1B did not.So I tried it again and nothing.I tried a couple more times and it did spray fuel but not every time I turned on ign.
I tried cranking eng and test light didnt pulse.I tried a couple more wires in the inj loom no pulse.
So my thought is when I grounded the OW wire with test light,thats when inj sprayed.? Im speculating of cource.

 

Seems likely that the injector loom and quite possibly the power resistor are malfunctioning. Well worth replacing these and cleaning the injectors, I would have thought. You have narrowed it down to fuel, so (assuming you have verified there is good flow the the rail - I cannot remember) this seems the obvious next step.

Greg

 

I've been reading on and off about this, but you started venturing into places I have no idea about, but your back round full circle now. Personally I think Carbs are a mistake and putting another brand of motor in there is a mistake also, and I do have reason's for both!
Back to the problem, I think I wrote earlier that your injector loom my be shot, well any of our cars of that vintage I know will be definitely on its way out, mine was just crap and fell apart in my hands. I would check your pulses to your injectors at the plug where the injector loom plugs into, if you get a pulse there then you know your loom is shot and I put money on it! At least like in any detective shows you can rule out another part of the puzzle if it works. Simply use a a light circuit tester and read this FI Harness Rebuild as I have no doubt in the near future you will have to do this also if not before, it also shows which of the plug sockets to check for the pulse, one last thing check and clean all your earth or body wires in the boot or trunk as you like call them.

 

Thanks for good info,Guys.This thread is getting pretty long,seems like I should know every nut,bolt and circuit on these cars pretty soon..
And yes I have very good fuel pressure.When I disconneted incomming line at 1A bank pressure regulator.and turned ign on,it fuel shot over entire eng bay.
I did check wires at inj loom multi plug,with test light.
Thats where the 1A inj sprayed when I check the O/W wire.
I'll check out the FI harness rebuild link.I hope its not ECU.Thanks for link Katoh.
I have cleaned all multi plugs and grounds.
I think like Greg said,its time to invest in a power resister,There only 59.00 at rock auto.
One question,Is it the power resister that creates the pulse to injectors or the ECU??

 

I cleaned the grounds at battery.
The grounds up by radiator on left and right.Do they have anything to do with inj system?

 

No. Cleaning the engine grounds always a good plan. LHS lower chassis rail, then to subframe LHS then to engine sandwich plate. Also good idea to install a ground direct from the engine to the chassis rail.

Meanwhile, I feel you should get the injector loom and resistor pack done and the injectors cleaned. You know fuel is not getting there, so where else to start?

Greg

 

Sounds like a great idea.
I just orderd new injector connectors.
Also,a ground strap,so we will see what happens.
I'll update later.
Thanks.

 

Does anyone know if one injector in the loom,has a broken wire or wires touching together,will that make all injectors not work..??

 

Not sure if that would cause that result, but certainly would be doing no good.

The injectors are grouped, in 4 banks of 3 which I think you may know.(1,3,5A) (2,4,6A) (1,3,5B) (2,4,6B).

So, if 1A (example) is shorting, then the other 2 in that group will be affected.

 

ok,Got it.thanks.
I'll check them by groups,but now just waiting for power resister to get here.
I replaced all injector connectors.
Hopefully this works.

 

Here is what I found,
I disconnected multi plug for injector harness and used digital volt ohm meter.set at ohms.(Ign off)
On injector side of harness no wires grounded.
On chassis side of harness the wires O/G and O/S are grounded.checked on a 20k setting.
I pulled plug connector on power resister and the K/S and K/G wires also grounded on the 20K setting.
I'm asumming,none of these should be grounded??Does this mean ECU is bad?
These grounded wires are the X and Y on the B bank of injectors .
To Update...If doing the same test above,I unplug both multi plug for harness and power resister plug.
The O/G and O/S wires on multi plug are not grounded now.Only the K/G and K/S wires on power resister plug to ECU are grounded.Wich narrows it down to pins 11and 29 of ECU.
One step further: with the ECU unpluged,checking power resister plug (unpluged from power resister) also multi plug still unpluged.The K/S wire is not grounded anymore,ONLY! the K/G wire is still grounded.
Ok,Im not a professional on this but,logic dictates that if a wire is not connected to anything,on either end and its grounding to car,that can only mean one thing.Its grounding somewhere along its path.Correct?
My schematic shows that the K/G Wire from power resister,only goes from power resister to pin#29 on ECU.
So if I find where that wire is grounding,maybe I can solve my problem?? Anyone?

 

ok,if anyone there? I spliced in a bypass wire from ecu plug to power resister plug.No more grounding at 20k on ohms. I turned on ign and 1A inj sprayed,but not 1B.Dont understand why
Im going to take inj harnesd off and go through it dont know what else to do.
Unless someone else has any ideas?