Question about 1988 Jeep Cherokee

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Engine cranks good fuel pressure good spark

I have an 88 cherokee just bought it the guy said it had low fuel pressure but if you put fuel in the intake it would run so i replaced the fuel pump and now it wont start at all even when i put fuel in the intake its getting good fuel pressure and good spark but it just wont start im running out of ideals i need help it just doesnt make since to me

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Timing gear

Posted on Feb 28, 2009

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1 Answer

Turns over, but why doesn't it crank?


Have you adjusted valves? Tested for spark? Did old engine go bad due to weak spark or low fuel pressure? Start by running basic tests=fuel pressure at key on, spark at plugs, correct timing.

Mar 04, 2016 | 2005 Toyota Tacoma

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Ive got fuel at the injector rod on my 1994 v8 jeep grand cherokee larado but the car wont start .. this all comes after runnin out of gas. its almost wasnts to but doesnt stay on at times and now won


If you ran out of gas there is a very good chance that the fuel pump relay has blown a fuse or requires a reset. Fuses and relays are in the main fuse box behind battery. When you turn your ignition on to the one setting before the starter engages you should be able to hear the fuel pump running. If it does not then check those fuses. If it does run then there is a good chance that the crank shaft positioning sensor needs replacement.

Oct 12, 2014 | 1994 Jeep Grand Cherokee

1 Answer

HHave a 88 nissan pikup truk wont strt it start yesterday wen my dad tookout the relay buttons n put them bak in but wen i tried it today it didnt start plz hlp


you all need to find out what is happening #1 make sure your battery is fully charge,#2see if there is spark at the spark plugs by may be using a old spark plug or by putting a phillip screw driver in the spark plug wire then while someone crank the engine put the screw driver close to the engine or were you get a good ground if it spark then you check for your fuel pump if you hear a humming from the tank then check the fuel pressure if that is good then you check for compression at all cylinders if all is good you may have a problem with the injectors,you should get a mechanic who understands how the engine works

May 03, 2014 | Cars & Trucks

1 Answer

Motor as no fuel


which engine?
post the symptoms, please.
my guess, it wont start?
or stalls?
and spark is 100% good (tests)
and now you suspect fueling system loss?
fuel is last check.
after good engine, good spark and if good , try test fuel (spray)
if motor starts for 3second test fuel, then you have lost fueling
we then do the fuel pressure checks in the FSM , every step, (6)
we check pressure cranking, many engines must crank to get fuel..

Jan 13, 2014 | 1998 Jeep Grand Cherokee

1 Answer

1998 jeep grand cherokee will not turn over but fuel pump is fine


fine? ( 30 to 40PSI , fine, not squirt tests or sounds)

EFI demands full pressure all the time, its not like carb cars of old.

first off, no engine stated ,so all help will be poor, all cars have engine options.. to work on any car , open hood, (USA commenter) and look up see that EPA sticker there, and the engine ID< and displacement?



That is first. (ill pretend , you drove to my shop and what id do)

i ask owner, when\'s the last time car was a daily driver?, last week or last decade>? (bad fuel, etc,....happens)



i stick finger in air, its 50F, not -40F air temp, ok not in Canada. cool. er its hot...

i open hood and see a I6 4.0L engine, with EFI. ok.



2: i check all the fuses. it\'s EFI and blown fuses, will kill the show.

3: i turn the key , and check engine lamp glows, (ECU is happy)

(ecu has juice , so boots and glows CEL, to say so)



4: i crank it, it cranks over 250 RPM, sounds like normal fast cranking

we all know that sound, we dont use the tachometer...



5: i then ask owner , evah\' tune it up this decade, answer no.

SSDD !

i then do the tune up, plugs were ratty. all spark parts, filters.

we dont use $100/hr labor to find ratty spark parts the install them

its called a tune up.



car runs like new. (end story) no?

or it was tuned up;.

so, i check spark it is blue-white on my test spark plug (new) times 6.

i then check spark timing, it\'s dead on, good, if off i fix that first.



if timing is off on most cars i check compression as some like

to slip cam timing. (i saw a V6 once with plastic timing gears. once burned ,twice shy , i check it all) (i do a compression test on all old motors. so I can see TRUTH, and potential future LIFE of engine)



ok, spark is perfect,please note my order, good motor?, good spark?

with bad motors and spark the fuel can not burn, not fully.



then, i try "test fuel" (can-o-spray) car runs for 3 seconds. and stalls.



my gosh, the motor and spark were good. verrroooooom stall....



(btw, this here, logic flow is bad on DOHC motors, 99% true) ask



i check spark plug tips and they are dry. (wet is flooding)

DRY !

i suspect low or no fuel pressure, i know from experience

that fuel pumps about 75% do not run only key on, only cranking

and running they run. so i check pressure.



i find its 10psi.

the story gets longer for flooding or injectors tests, ill skip that.. ask.

so 10psi,. i find

1: 12v to pump is really just 6v, if fix bad connector up stream from pump. done.

2: if 12v to pump cranking, mine was 11v, but the starter does that. drop so is ok. (study starting systems) , its good line voltage is good. cranking.



3: i then check the fuel pressure reg, and find the thing stuck wide open , i replace the reg. and pressure is 34 PSI (wild guess. didnt look yours up. ) car runs prefect now.

or

4: i find FPreg ok, but pump is weak, new pump saves day..

i have a scope and can see this pump is noisy, has a bad commutator segment, deep inside it... scopes, rule.

all above is good?

if pump pressure is at spec. cranking, then

do this long story, omitted due to fingers sore.

ask

the pump tests and spec are all covered 100% in a real FSM.

the spec is covered at alldata.com, log in and see it.

btw, all EFI just hates low fuel pressure.

the whole system is turned for good pressure,

and many systems do not even monitor it.

To understand that read the books by, Greg Banish



http://www.amazon.com/Engine-Management-Advanced-Greg-Banish/dp/1932494421/ref=sr_1_1?ie=UTF8&qid=1388070570&sr=8-1&keywords=greg+banish.



the pressure must be at spec, and must regulate perfectly

or the ECU fuel tables are all TRASH.



hard starts. (fast starter) nut shell.

1: bad fuel. or running summer fuel in winter

what is your air temp, not stated, and is big factor ,if very cold.

2; no tuneups. ever done.

3: bad spark or timing off,

4: low compression.

5: bad ISC, try starting with 10% throttle ,to mimic a good ISC.

6: flooding. soaking wet spark tips.

7: under fueling, dry sparks.



try test fuel. if dry.

Dec 28, 2013 | 1995 Jeep Grand Cherokee

1 Answer

92 jeep cherokee how do u check the fuel pressure, spark and crank position sener


fuel pressure ;-on the pipe below filter or n your injector rail press the valve n you will see how much fuel is being pumped and do that with the ignition on .SPARK;-take out 1 plug wire (any)put an old plug in it and place it next 2 any metal place in the engine then crank n if there is spark you will see it palsing spark while u crank the car and the sensor check on the crank you will see sort of a plug ,follow it and see if its pluged in

Oct 23, 2012 | Cars & Trucks

1 Answer

Jeep is hard to crank an when it does it runs rough for a few minutes until you rib it up then it runs ok but does not get good fuel milage, i replaced crank sensor,spark plugs,three fuel pumps and...


It sounds like there is a fuel leak. Most possibly internal to the fuel pump module. There is an o-ring above the fuel pump on the module that deteriorates and allows fuel to drain back into the fuel tank. It causes a host of problems including yours. Connect a fuel pressure guage, start the engine and watch the pressure increase to @49psi. Then shut off the engine and check the pressure drop. It should not drop bellow 20psi within 10min, and still have some residule pressure the following morning. If not then the o=ring will require replacing, Sounds like its been going on a while. worth a look!

Aug 21, 2011 | 2000 Jeep Grand Cherokee

2 Answers

96 grand cherokee crank no start, no spark from


have the crank sensor replaced this controls the spark and injector pulse it is located on the drivers back side of the engine above the transmission housing!

Jun 08, 2009 | 1997 Jeep Grand Cherokee

1 Answer

My 1993 Olds 88 wont start cranks but wont kick over. Fuel prob


3.8 are known for ignition trouble but first use the fuel release valve located on top of engine under a screw cap to see if your getting fuel. It takes 4 things to make engine run fuel spark air and compression. But most likely the Ign control module or crank sensor. So try this
1) check the fuel pressure
2) check for spark
3) compression test

Apr 26, 2009 | 1988 Oldsmobile Delta 88

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