On Sat, 2 Jul 2005 03:35:52 UTC timcole <DoNotEmail@AutoForumz.com>
wrote:
> "Ty78" wrote:
> > I don't know much about cars, so please be patient with me ,
> > and please help. My 89 jeep cherokee 4.0 4x4 just statrted
> > taking about 30 seconds to start. It cranks fine, and fast,
> > btu it takes a while to start, and when it does, it kind of
> > sputters, and then it runs perfect. If I turn it off, and
> > immediatly restart it it will start just fine, like it always
> > has, but if i let it set for over 30 seconds and restart it,
> > it is again hard to start. In the past 6 months I have
> > replaced the plugs, wires, dist cap, rotor, starter, fuel
> > pump, cadaledit converter (spelled wrong), and exhust. What
> > could this possibly be? Like I said it runs fine, after it
> > starts. I really appriciate any and all help!!! THANK
> > YOU[b:f0c179ca4f][/b:f0c179ca4f]
>
> Hey - me too! Not only that, but the engine misses erratically, maybe
> two cylinders! Started a few months ago -- 118,000+ miles -- before
> that, it ran fine.
> I have replaced plugs, leads, distributor cap and rotor, fuel filter,
> and fuel injector o-rings; IÆve blown out or cleaned the CCV line,
> the Throttle Barrel, the TPS (and readjusted it according to specs),
> and the IAS.
> What I do have wrong: I canÆt get the o-rings to seal on Fuel
> Injector #3; I might have a fuel pressure problem (donÆt have a
> gauge).
> Not only does it miss and squirt gas out of the Injector seal, but it
> dies when I take my foot off the accelerator (it wonÆt idle any more
> without stalling); it stinks something fierce on the road and attracts
> a lot of attention; hesitates on acceleration from a stop, but
> occasionally runs fairly decent, especially from cold.
> A few months ago, this thing beat a lot of people from the light
> (maybe I did that too often . . .). IÆm retired and lost half my
> pension and all my benefits and life insurance -- still have a
> mortgage. I have a summer job inspecting corn fields and need my Jeep
> for that (gets hilly, and slippery under the irrigators).
Tim, the problem is that the leaking injector seal lets the pressure
drop - you would see this immediately with a fuel pressure guage. Fix
the injector seal! Open the hood and look where the fuel from that
injector is going: straight down onto the exhaust. Are you sure the
leak is from the o-ring on the rail? Both of the ones I've replaced
were actually leaking around the electrical plug. For the first, the
cure is new o-rings (careful, some kits have two sizes and
compositions so put the right ones on the right end). FIX THE LEAK!
It's a fiew waiting to happen.
Ty, yours sounds like a fuel pressure problem as well but since you
don't see a leak it's more likely to be bleeding off pressure back to
the tank. You have a pressure regulator on the forward end of the
fuel rail that will do this if the regualtor is shot and leaking
through. Try this: turn the key on and listen for the fuel pump to
run (don't go all the way to the starter position). When it stops
running, turn the key off then turn it back on to cycle the fuel pump
again. Do this several times then try to start the engine. If it
catches fairly quickly, then it's likely a pressure problem. To be
sure, do the key cycle thing a couple of times then turn it off and
press the center pin in the schroeder valve (oversized tire valve)
near the front of the fuel rail. Hold a rag to catch any gas. You
should get a decent spray even after waiting 5-10 minutes - mine holds
a noticable pressure overnight. If it just dribbles out, then you
know it's fuel pressure. Since you've changed the pump, it's most
likely the regulator but there is a test for that so write back when
you try the above steps. It could also be losing pressure through an
injector leaking into the manifold so a couple more tests migh be
needed. BTW, the 87-89 4.0 used a Renix fuel control computer and it
takes relatively long to fire up cold under any circumstances (about
one full turn of the engine). 30 seconds is way too long, but 5-6
seconds is not that unusual. The later MOPAR models catch right away.
For both of you, a fuel pressure guage is $12 - $18 bucks at the local
Advanced Auto or Auto Zone. Worth the price is savings on unnecessary
parts and agravation
--
Will Honea
