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So, if the LH isn't getting an RPM signal after 1-2 seconds, it shuts off the fuel. The only place the LH gets an RPM signal is the EZK. The only places the EZK gets an RPM signal are the crank sensor and the hall sender.
this explains why no tach reading... there is no RPM signal and so the pump doesn't get power because the LH isn't getting the signal from the EZK
hmmm but why the limp along running that one time with the fuel pump on place, but no tach signal...... remember, the holbert car had no tach signal when I got it and ran well. it must be a tap on the signal that was broken .
im still puzzled how the engine was running without the jumper, blowing all sorts of black soot out the tail pipe and didn't have a tach signal and didn't have any fuel pressure. sounds like need to check more of the injector /ecu grounds
Find out why the relay doesn't work and fix that, since it's a known problem and you'll have to address it sooner or later.
LH, EZK, or speed sensor; wiring or grounds in those circuits. I believe I read that a dwell meter can sense the RPM output from the EZK to the LH. If it reads correctly, that would point to the LH.
In the meantime, maybe someone can answer your 'why did it start once with the relay, chug chug, and black smoke' question. My only guess is that the speed sensor wasn't sending out a pulse for every revolution and now it's not sending out any.
Find out why the relay doesn't work and fix that, since it's a known problem and you'll have to address it sooner or later.
LH, EZK, or speed sensor; wiring or grounds in those circuits. I believe I read that a dwell meter can sense the RPM output from the EZK to the LH. If it reads correctly, that would point to the LH.
In the meantime, maybe someone can answer your 'why did it start once with the relay, chug chug, and black smoke' question. My only guess is that the speed sensor wasn't sending out a pulse for every revolution and now it's not sending out any.
The relay seems to work, as it has no problem firing up the fuel pump on the ignition cycle of the key. we don't know if its working on start up, or what was going on when it was blowing out black smoke barely running. what I do know is the fuel pressure was zero , and when I jumped it, it stays at 45psi, but wouldn't start again. I think we need some ground checks. so far, all the connections seem to be showing good.
Yes, if the FP runs during the ignition cycle then the FP relay is fine. If there's no pressure in the rails after that, with the relay in place, then the FP is not running. If the FP is not running when it should then the LH or something upstream that tells it to run is malfunctioning. Among those are the the crank position sensor, LH, and EZK.
Unplug all the injectors, if you have a short in those you can have one or two faults, the injectors stay wide open and they can shut the entire circuit off.
Unplug all the injectors, if you have a short in those you can have one or two faults, the injectors stay wide open and they can shut the entire circuit off.
This sounds the most plausible! will try that too!
I cant think any other way that the car is trying to start and there is no fuel pressure. (but pressure when the fuel pump is jumped)
Unplug all the injectors, if you have a short in those you can have one or two faults, the injectors stay wide open and they can shut the entire circuit off.
more likely, could that short be after the injector and in the harness or near the fuse panel?
I know you all have heard this question before, but the friend with the '88 stroker cant get it started. its run kind of spotty over the years, when i had it , we got it running pretty well, but occasioally it would floodout on start up and dont know why that was, but eventually, it would start, make a bunch of smoke and then run fine. Now, after doing some window wiring work, he cant get it started.
I was suspecting a leaking injector (if that is posible for an injector to leak fuel after the engine was turned off) as a cause for the loaded up starting issues. but , after going through the normal chasing of the tail, process of jump'ing fuel pump relays and things, it still wont start.. he says, both bank fuel injectors are clicking. fuel pump is running, and he says he sees a spark on both disties.
so, i had him disconnect fuel regulator (RRFR) vaccum line and put a vacuum on the nipple... it held vacuum.... but then checked the dampers, sure enough it didnt hold pressure and then gas came out of the vacuum gauage . not a lot, but a little. so, somethings leaking on the Damper... (diaphram?)
before that, had him crack the fuel line nut and gas only poored out, not sprayed out like it was under normal pressure as we have seen before.
can a slight crack in the diaphram on the damper cause enough fuel to pass into the intake. or maybe its allowing all the fuel to be pushed back into the fuel take , like the RRFR does? (i dont know how dampers work and if there is a return line that can hurt pressure being kept in the lines)
im going to see the car tomorrow and thought the wiz kids here might give me something to go on.
thanks,
Mark
MK,
Your friend should sell me this car so I can put in that spare Motec M8 in it now that I also have a full blown M880 as well. The M8 has dual wideband Lambda, and a bunch of stuff that would be pretty nifty on a N/A 928.
Ripping out the existing butchered harness and wiring up a new harness will solve all those running issues.
If he doesn't want to part with it, I hope you get it fixed..! Patience of Joab needed......
right and he is the one who used starting fluid over and over and over...trying to get a 16 VALVE to run ended up washing down the cylinder walls and destroying the bores.... it is all a learning experience.... some just cost more than others.
When there is raw fuel running out of the splits in the exhaust pipe behind the convertor....the cylinders have been pretty full.
And fuel doesn't compress much, last I checked.
I agree. Im surprised as well. we opened all the plugs and continued the tests, and no fuel seems to be pooling up in the engine cylinders, and nothing being pushed out the plug holes. could it be that they started it with no start for so long the fuel kept on getting pushed out the exhaust valves???
Originally Posted by James Bailey
right and he is the one who used starting fluid over and over and over...trying to get a 16 VALVE to run ended up washing down the cylinder walls and destroying the bores.... it is all a learning experience.... some just cost more than others.
Jim, that wasn't me.... that was a so called experience shop.... I found the issue on the next engine, and put a resistor in place of the TEMP II and got it to start.. also, initially , was able to wedge the AFM open slightly to get more fuel to get it to start. I NEVER would use starting fluid. Ive never damaged a 928 engine.
I agree. Im surprised as well. we opened all the plugs and continued the tests, and no fuel seems to be pooling up in the engine cylinders, and nothing being pushed out the plug holes. could it be that they started it with no start for so long the fuel kept on getting pushed out the exhaust valves???
Only if all 8 cylinders happen to be on the exhaust stroke when the engine gets cranked over, full of fuel.
Which is, of course not possible.
Any cylinders coming up on a compression stroke that have more than about 100cc of fluid are going to have a very tough life.
04-17-2015, 03:13 PM
