I have a 93 Sidekick JX that has been giving me a lot of problems lately. After replacing the fuel tank (rotted) fuel filter and fuel pump and finding a corroded plug for the FP cicuit behind the left taillight and fixing that, I STILL have a problem with the car starting after sitting overnight. I know about the IAC but the car runs perfectly once it starts. 1200 rpms when cold down to 850 when warm. No misses, bogs, or anything. When I crank it in the morning it sputters once, but wont start. The one thing I noticed, however, is that in the AM the fuel pump runs only a second (or less) and the relay clicks off. If the pump runs for the 3 seconds it starts right up. Thought it was the relay so I jumped A & B, pump runs all the time the key is on, but still no start. My question is what times that 3 sec interval, the relay or the ECM? Could the ECM do this and yet the car runs great when it does start?
hello 93 >??????
what engine, 8v or 16v.
the ecu turns on FP for only 3 seconds, ( but it pumps to 24psi and then goes quite) ( the FP relay is the slave of the ECU)
the 1 second only means , that leak back was just a tad. (good)
the acid test is a pressure guage connected the to screw hole
you have on the lift side of the Fuel filter banjo bolt.
if filter is good, AND pressure is good , key on and idling then
starting pressure is not an issue.
exception would be:
if the injector has a clogged screen (all injectors have a 10micro screen inside, so says all injector rebuilders)
if it's a throttle body?? , just have someone crank it and look down bore with a mirror.
if it sprays and does not start, the its not a fuel problem.
Your IAC could be stuck closed or clogged.
(there are 2 stages of IAC in the unit) one for starting the other or running.
your problem is:
0: tune up, old battery or too cold for old battery (December)
1, loss of fuel (for many reasons)
2. no air (iac stuck) ( cause too much gas "x gas + no air=rich"
3. weak or no spark , until battery voltage rises above 10v.
4. starter must spin engine fast ( if it is too slow , ecu will wait)
if battery drops too low , ecu will cut out too.
engines crank at over 8v but ECU need 10v min. (2 volt diff)
holding gas pedal just a tiny bit during a start should prove #2 .
Hey , how about a bump start.
park on hill and bump start it in 2nd gear.
automatic.? ( we dont know)
please post with accurate car type, just like buying parts , they always ask the same questions. please tell us what you have.
also knowing the ambient temperature is useful or your location.
its -25c in north Canada now. or +23C in Lima.
let us know more.
like battery voltage during cold cranking.
fuel pressure before cranking.
You imply that the car runs good hot. EVen flying up hills.
if that is true then the fuel side is good.
lug engine up a hill hot in 4/5th gear and load it down good.
you just used MAX gas flow. ( see?)
its a cold start problem.
is battery at 12.65v before starting car.
have you tried another battery,
sorry for dumb quesitons but I cant hear your baby spin!
mine spins like a top , cold. but its only a 1.6liter engine.
it should.
good day and Happy holiday from the Puget Sound.
No ice , cool......
Thanks for the reply JTGH. Sorry for the lack of info, this thing just has me obsessed. Its a 1.6 16V SOHC MPFI engine. The battery is good 12.6V and I get the same at fuel pump. Today did something new. Car sat all day. When I went to start it did the same thing. Relay on-off for 1 sec. No start. Turned key off and on and cranked couple times, then, I turned it on and pump ran 1 sec., clicked off, then before I turned ig. off it clicked on again and ran 2-3 sec.! I never touched anything, it did this by itself. Of course it then started immediately as it always does as soon as that relay stays on for 3 sec. This has me totally baffled. My next step is to get a "noid lamp" and check for inj. pulse in the morning when it does this, because my gut feeling is that it is a ECU problem.
each time you disrupt power to the ECU , you will get 3 seconds of
FPrelay. (you replaced many things was the fuel pump new or used) A bouncing key contact is pretty normal for an old car.
dont forget , FP is ON during ALL CRANKING (if there is spark)
if ECU sees spark stop, INJECTIONS MUST STOP (fire danger rules)
IFWM: (if it were mine, grin)
I would put a meter on the Fuel pump connection as it enters tank.
no sure how to splice in there but , if possible measure the fuel pump voltage , under your conditions.
my pump page >>>bomba
1.6L KEYON-nostart ----35.6–42.7 psi 1.8L ----38.4–44.0 psi Static test:
1.6L Keyoff , min. 28.4 psi for one minute. (leak down spec) , Residual pressure test.
1.6L KeyON-start --- 29.8–37.0 psi 1.8L ---31.3–37.0 psi, Running pressure.
as you can see the leak down is 1psi per minute.
with a guage , you might see the pressure leak down from 30 spec
to below 10, quickly, that is a bad pump or bad FP regulator on fuel rail. (stuck open)
My web page shows all 8 possible tests, just about every possible failure possible.
You wont be able to do test 8 , requires scope.
test eight is cool because you can see bad motor brush segments with out removing gas tank, (just like your dr, and his EKG)
I saw a man die by poring gas down a carb once, other person craking away like two cazy fools. ( I yell and screamed, and got the finger) I guess the Modern ECU protects people from them selves.
some cars pump up to 60 psi (chev. truck) , that's lots of gas if it breaks looses.
please remember to pull the FPRelay while runing to purge gas out of system before opening lines, Green socket below ECU on mine.
Went out this AM (20 degrees) no start. To check ECM I jumped diag. plug. No code 12, but CEL light on. Disconnect batt to clear, (I have a bad speed sensor so light is always on till I clear, then comes on again when car moves). Turn on ig, light on, put in jumper, no code 12. Went and got Noid light. Hooked it up, cranked engine and got VERY dim flashes. After much cranking and off/on unflood mode car started. Ran very lean, would not take any throttle, would not idle (stall). CEL light on, but car hadn't moved yet. Kept it running a few mins. and ran heater. Car reached op temp. and about 2 mins later suddenly straightened out and ran fine. It was like throwing a switch. And as soon as it did the CEL light went out. Anybody know the best place to get an ECM for a MPFI 1.6 16v 5-speed?
hello mr 93 16v MPI>
bad cold start , runs PERFECT hot ? <<< that your new symptoms.
and what is the no move , CEL code? ( dont skip getting that...)
you need a working vss , me thinks or ECU will drive you crazy.
ebay has the best deal at $70 , many here has used his service with no complaints.
only one guy at 70 ( rest to got 200)
ASSUMING YOUR SES MILEAGE LAMP MODE IS NOT TRIPPED? (yours isnt, for others)
I place jumper first , key on, no start and read code 12.
if the car will not pass: the code 12 or some other code, then the ECU is bad.
make sure vss plug didnt fall off back of speedo. just a plug goes to ecu.
vss pulses come out of speedo. ( spec is one rear wheel turn once , 1 click)
your car is a Air Density engine (MAF based) it will run on TPS if Maf disconnected.
It will run with TPS disconnected and MAF still connected , both ways will envoke limphome mode , rich and retarded but car will run. < GREAT test trick.
Your engine is devoid of any MAP so removing both MAF and TPS kills engine.
Your car hates air leaks, and the EGR is infamous for leaking.
You computer may be bad but make sure EGR is closed solid.
make sure no air leaks to the induction plenum at all. (inside of intake manifold)
that switch of mode is simple, the coolant temp sensor passes 147deg F and ECU says to self, hey now it time to attempt CLOSED LOOP, and BINGO IN SHE GOES.
To enter , the ecu needs a good maf and oxy senor to hold it.
tell me how car runs HOT. ( full power ,no flat spots ?)
a car that runs good hot and not cold is interesting .
KICKS:
the colder it gets the more fuel is injected , but if you car has a bad ISC ,
the engine will just flood and as it gets colder, it will flood even more!
this happens because the stupid ECU can not tell the IAC is busted. << that is it.
if your car always floods and pressing pedal to the floor unfloods it, then it is in fact flooded , if holding the gas pedal 1-5% down at start helps cold start then you have again proven the ISC is BAD. ( 1% rule only turn after 1 successful hot run )
Cold start, cold run and hot run are ALL different modes inside the ECU,
vastly different.
tell us what you are driving and what the car does bad and good , greatly helps the people on this end , to know what is wrong.
tell us the Good , the bad and the Ugly , hhehehehe
This is a problem that has been nagging me for months and I'm sure you can appreciate the difficulty of trying to describe it in this forum. Plase be patient with me, as I'm trying to describe a very complicated problem with as much brevity as possible and I don't think I'm doing very well. This car seems to have 2 modes, runs great (99% of the time) or bad. It started a few months ago very suddenly as I turned on an exit ramp from the highway. I think it went into limp home mode by the symptoms. (same ones as this AM) but after a few miles it just as suddenly cleared up. I thought (hoped!) it was clogged inj. and ran cleaner and dry gas in it. Once in a while would still do it(every couple days) generally at startup. the amount of time the car was off didn't seem to matter. If it started right away, it was fine. In fact it only acted up once while it was actually running. I thought ECM right away because it was so intermittant and all other times it ran very good. Then the gas tank started leaking (rusted) pulled the tank, saw holes it the top and thought AHA! thats the problem! Got a good used tank-same problem, pulled tank and put in new pump- same problem, changed filter again-same problem. If I turn the key and the pump runs 3 sec, I KNOW it will start right up, and it does. If the pump only runs for 1 sec, I KNOW it will not start, and it doesn't.
I have checked grounds and plugs on everything I can find
checked every sensor I can
have 12.6v at the pump
when the car is in its "doesn't wanna start and run mode";
CEL light stays on even when running
cannot retrieve codes
noid light on inj. very dim
pump only runs 1 sec.
unflood mode really doesn't seem to matter, only cranking for long periods(10-15 sec) and very difficult to get running.
If the car starts right away, then there are absolutely no problems. Everthing works as it should. Cold, hot, under load, anything, is perfect. Cold idle is where it should be, it idles down to 850 when it warms up. Never stalls, doesn't miss, runs strong. It seems to be a case of everything working as it should..... or not at all. There is no in between, no "overlap" of symptoms. Its yes or no. Sorry for the long post, but while I am certainly trying to fix my car, I think this might help others because it surely isn't something you're going to find in a service manual.
dont feel bad, mine had 10 majors ,to fix before I could run it. (it's old and tired)
cars and intermittant problems are very very hard to find. ( many just give up)
long post is not a problem, ( as appropriate to the issue, really)
if you took it to a mech, it would be long post high bill , huh ? my joke.
one nice lady, here ,took car to 5 mechs just to get the blasted Mile Service switch thrown. ( its hidden and can only be felt, never seen, cute trick that is)
You post is very clear. and short.
Your whole car is multi modal, in that it does what it wants went it wants , no rhime or reason.
toss coin, one day ok, next day, hell.
I'm sure you figured out the key on 3 times and it will start trick.
with out a pressure gauge its a crap shoot.
That ECU is bad. ( that is my guess based on your above statement)
if at any time it does not pass my 3 tests, it is in fact bad.
1- lamp test
2- demand code 12 test. ( no code 12 or others,then ECU is INSANE)
3- spark good no injection, ECU is bad.
the FSM has a flow chart and says, simply , replace ECU.
I believe you just failed #2 , if yes then our ECU is like all of ours out here.
Heck with the FSM:
pull ECU, look under lid , see Black soot ? ( my ECU blew up 2 times)
look at capacitors, they are made buy Rubycon, they suck, no other words can say how crappy they are. The explode, they leak , the even piss fluid all over the inside.
I have 45 year old Panasonics (NEC) still good in my Real to Real tape deck here.
side note
I just bought a spare ECU(2 actually) and fixed one that was very sick.
I'm trying to find one that is unrepairable. ( so I can canablize it). ( another story))
moving on...
Looking inside , will convince many to take quick action , others take it to a tech, others
exhange it on ebay.
the Ebay fix is $70 , and the guy does good work.
your instincts are good and no you are much better than just throwing parts.
your above proves that.....
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Fuel pump relay?
Linear Mode
