(07-06-2020, 09:28 AM)danstrayer2 Wrote:both are hard failures. ECU sees those,(07-06-2020, 09:22 AM)danstrayer2 Wrote:(06-26-2020, 10:41 PM)fixkick Wrote:(06-26-2020, 07:43 AM)danstrayer2 Wrote: big problem, please help if you can. Last night I backed up on gravel road for 300 feet, at high speed, pulled in and parked. This morning this happened:are you going to run the engine 300,000 miles on a 60k mile cam timing belt.? sorry had to ask... common failure this. and worse next.
Good start, all sounded well and normal as it has been for a year: in less than 2 minutes, extremely rough, only run (barely) at certain throttle openings, eventually dies completely, heavy fuel usage. No restart. Let sit for 20 minutes, good start, in 45 seconds goes to extremely rough, then no run. Will run at high RPM, with some occasional misfire.
Here is what has been done:
removed cat from exhaust system. Same.
Fuel volume from rail= very good. Fuel pressure in rail just under 40 psi. Return fuel line OK. Tank pressure relieved.
Rail leak-down test=OK, holds 35 lbs for 10 minutes, (very slight drip at my fittings).
Air cleaner removed.
here's the killer: Vacuum test about 10-12 inches hg. Plugs very sooty. It's lke fuel is justbeing dumped, but injectors don't leak, even if one did, all plugs are sooty. 4 injectors did not fail at one moment.
I saw the FSM on exhaust blockage, removed exhaust manifold completely . Problem/symptoms remain.
Could this be valve timing as in slipped belt?
MAF is fine. EGR is OK. It started when I backed up, WOT...coincidence?
I am stumped. It runs really well just like always....then 1-2 minutes just deteriorates to will not run. What can it be?
is the front crank pulley 17mm headed bolt loose? 94ft/lbs only is spec.
compression is 180PSI not 80. do a compression test on any engine, that will not run or has low power. first ( do it with the throttle blocked open)
at sea level not DENVER.
KEY ON< CEL lamp must glow does it.
and then with the DLC diagnostic jumper inserted (paperclip) DTC code 12 blinks out, (means good) all others bad, or worse.
worse CEL dead.
worse CEL can not blink but stuck on. (turn off CEL nag switch if car is FED and not Calif, marked on hood sticKer)
The ECU can go to failsafe (limphome mode) or worse BACKUPMODE.
all those suck fuel like mad and wants to flood the engine
CEL Dead Cell Dead is the CEL dead (check engine limp, #1 check on all cars 1989 to now never skip CEL and DTC checks, (scans in 1996 up)
use the DLC get the ECU DTC flashing codes, do that first , if the CEL lamp is dead that is a bad lamp or stuck in HORRID BACKUPMODE(means bad ecu)
Got DTC 12 = normal yes/no.
a bad ECU is most times just needs new CAPS. (they love to fail on this car if black caps and marked RUBICON)
------------------------------------------------FINALLY the CEL works and we HAVE LIMPHOME HERE !!!!!!!!!!!!----------------------
So..getting into the TPS...DTC=22,45....here's the mystery:
Backprobing the blue/w wire from TPS , I get 5 volts, but no voltage at any time from the Gray/red wire, which I understand is the 5v reference voltage.
If I unplug that group from the ECU, B6 pin on ECU has 9 volts, but plug it in and no voltage. (just leakage) you mean you pulled the B connector group..... doing that kills power to the ECU and is useless tests)
you killed (conn group B pulled) dead B1 and B2 and B15 grounds, this test is bogus. for 5vdc checks.
Checked continuity from ECU yellow plug to TPS, that checked OK. HOW can there be 5 volt to the blue wire? (is B connector pulled here, IDK)????
what blue wire. I miss almost all testing details.
the #1 cause of blown up +5vdc REF is some one grounding out sensors with a jumper wire, or to 12vdc.
#1 top cause, hot wiring ECU is WRONG and so are SENSORS.
if you pull the B group you lost ground and the ECU goes dead for lack of power that includes, IC7 and 17.regs. (VRM)
if you pull the A group you lose 12dvc power, and again ECU goes dead and all sensors dead.
never hot wire electronics, ever, or you will blow things up, I promised, this is not 1950 Dodge. with only tube radio with electronics.
This CAR also can not have any outputs grounded or worse jumped to 12vdc battery feeds or you will blow the driver transistors to hell. boom smoke.
5vdc ref is AN OUTPUT TOO.
I added RED later, to make testing vastly more easy and no smoke no boom.
22 means TP pin output is dead, 1vdc is normal at key on or idle. (a.k.a. throttle angle pin)
5vdc pin at TPS is power, and is good.
says the TPS is broken, cracked inside or wiper for TP pin a wreck inside, (all are bad TPS) but...
unplug that group means? what, at the ECU , that done will cause ECU go to nuts. and is invalid test.
the ECU runs on 12vdc, (A group 12v , B group ground)
the ECU inside has two +vdc power supply regulators ( 12v to 5v)one for the logic inside 5v and one for that runs sensors out side the ECU,
we later learn 5v is blow up;./
TPS is one such sensor the 5vdc pin on the TPS is just power pure raw, 4.75 to 5.25v is spec.
and that works. here.
what does not work is your TPS,. it is bad. or this.
TP pin is called throttle angle , 1v to about 3v range. 3v is WOT, or even 4v. at WOT,
the TP pin can fail only 3 ways, (4th is 5vdc dead and is not)
1: TPS bad.
2: the TPS was installed and the index pins not aligned. at that time, making it dead. (tps mech, flloats inside doing nothing)
3: TP pin is shorted to ground. or the wire sure.
the TPS has a ground pin too, and if is cut open TP angle pin, goes to 5v and DTC 21 happens not 22.
dtc 45 is the tps idle pin stuck at 0v, and is really a bad TPS. (or 5vdc dead and is not) no way in hell both wires are grounded out , TP and idle switch but , index failure again sure.
if you remove the TPS and the inside index, spinner is shattered yah, that is it. too.
if the TPS is bad both can fail. 22 and 45. what to do is bench test the TPS
Testing 1,2,3,
or on car advance the throttle key on engine off and see TP pin voltage move from 1v to 3v or 4vdc, if not the TPS is bad, or the index pins set wrong (as in mounted wrong installed)
the TPS is only a passive variable 5kohm resistor, no electronics inside. no transistors, just carbon film and gold sliders.
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