extended cranking time

[louielouie]

hiya.
newbie here.
in 1990 i got a jeep cherokee.
the engine will turn over for what seems like a full thirty seconds sometimes when i try to cold start.
after it has cranked over sometimes, when i try again it starts right up.
for a re-start it starts right up also.
i have just assumed that this is the way it is.
i talked to another jeep owner and he said his does the same thing and his wife's starts right up.
what's wrong with mine?????? jeep that is.

 

[mud4feet]

Re: RE: HowdyHo!

Welcome to Jeepz!!!! Sorry I can't help (TJ owner), but you've come to the right place. There's a BUNCH of very knowledgable XJ owners on here and I'm sure they'll help you out.

mud

 

[Joopin]

Hey there, my YJ does the same thing! I can tell you what WILL NOT solve the problem though... these are things I have done thinking it would help. Optima Red top battery, new starter, new plugs, wires, distributer cap, rotor, and ignition coil. If you find the problem be sure to let me know! I just chalked it up to being an older engine (1991) that has almost 206k miles on it! Oh and welcome to jeepz!

Joop

 

[Bounty__Hunter]

Try changing the fuel filter, could be taking longer to build up suitable fuel pressure at the engine.

 

[graewulf]

Re: RE: Spare on the roof made for some excessive roll

also, when you get in, turn the key on (not to start) and wait 5 sdeconds then try to start - see if it makes a difference. I know my GC takes longer to start if I don't do this.

 

[ROGLSTUBB]

Re: Mingez went wheeling today. ***Warning!!! LOTS of pics

Mine is bass ackwards the colder the outside temperature the quicker it starts. The remote start will start on the first crank cycle when is cold when it is warm it will start on the second. I would agree with the fuel filter thing. If would definatly be a good place to start.

 

[MudderChuck]

Re: Mingez went wheeling today. ***Warning!!! LOTS of pics

Some of this is supposition (guess) some is fact. There is a ball check valve in the fuel pump, that is supposed to help hold pressure on the fuel rail. There is a leak down test for the check valve and the regulator, pressure shouldn´t drop below about 20 PSI (starting pressure at shut down around 39 PSI), in a half hour, after engine shut down.
Excessive bleed down is supposed to be a major cause of long cranking periods.
Mine tested within spec.´s, plan two. Engine has to be cranking at a bout 300 RPM to get the CPS, to work right. Possible a sluggish/marginal CPS or a weak battery. I cleaned all my grounds. Made sure my battery is good. Tested my CPS.
A TPS adjustment, seems to help mine start easier. Isn´t really cold enough here, for a good test, but things seem better.
TPS is fixed (I believe) non-adjustable after the 90 model year.
I also cleaned my IAC (idle air controler) it was jammed, this may also have a bearing on start up. Also noticed, no pedal, is most times the best start up and like mentioned before, leaving the key in the run position for a few seconds, before starting also seems to help. Hard for a person who has driven a carburated motor, not to push the pedal down, but the FI motor seems to start easier, with no gas pedal applied.

 

[graewulf]

RE: Re: RE: stain

If you are fuel injected you should not touch the pedal during cranking - this will definitely cause starting issues. The computer, as you have found, is set up to start best on its own. This is why you can easily install a remote start on a fuel injected motor, and not on a carbureted engine. Put the key in, turn it on, wait a few seeconds and then turn it to start. don't touch anything else and you get the smoothest start.

 

[dingus]

my '90 did some weird stuff while starting (like yours) when the cranksensor was on the way out...

 

[XJNick]

Hi,

I think MudderChuck's talk about the fuel system pressure is definately worth looking into. If the fuel system is not holding pressure after the engine is shut off, that means that at every start you have to wait for pressure to rebuild in the fuel rail, which results in a delayed start. Check the system for proper pressure holding

The other thing worth checking is the battery and all main connections between it and the starter motor. Keep in mind that the battery voltage alone is NOT a reliable indication of the battery's health. You need to watch the voltages under load to see if the battery has become weak. Under the load of the starter motor, a weak battery could experience voltage sag down into the 10-11 volt range, which for a 12 volt battery is effectively DEAD. Lower voltage means less overall power is going into the starter motor, and thus it won't be as strong and may not start the engine as quickly as it use to.

You can check for this by placing a good voltmeter on the battery while starting the engine. The voltage WILL sag some, but it should not be significant. Of course, a digital voltmeter will give more accurate readings. If the voltage is sagging alot, the battery is probably weak from incorrect charging or due to age.

Good Luck :mrgreen:
-Nick :!:

 

[beantown]

And here I thought I was the only one that would throw a battery, plugs, cap, rotor, wires, filter and come up with no change!
Mudder are you some type of prodigy or somethin'?
Actually, are you for hire!!!
Thanks for the tips, I am going to tear into it this weekend.
gaaagaaaaggaaaagaaaggaaaa vvvwwwoooooommmmmmmm.....

 

[beantown]

And all I had to do this whole time is turn the key, wait five seconds for the glow plugs to warm up then fire it!!!!

Wait a flippin minute......... glow plugs on a 4.0!! :lol: :lol: :lol:
(that was a joke fella's, b4 you start yellin at me!)

I love my JEEP! She's quirky but tuffer'n hell!

The waiting 5 seconds does seem to help :shock:

 

[90Xjay]

I thought we had a thread about this topic and I looked it up.
Back in Jan of this year.

Here is a copy of what I posted back then

There is alot of good sound advice in that thread about this topic.

My 2 cents.........

I know a brilliant fellow who operates an independent garage in my town. He specializes in fuel injection systems. When I was doing my exhaust manifold, I took my fuel rail to him to have it checked before I re-installed it. He told me that he had a contract for several years servicing a fleet of 25 vehicles with the same 4.0 inline six. We discussed long start cycles and while fuel pressure must build before it will start, he claims that minor timing chain wear with higher miles is the problem alot of times. He has a method of clocking the distributor cap slightly to compensate. The problem is that the rotor is throwing spark just forward or behind the metal contacts inside the cap. The timing chains are so strong they rarely need replaced. But his method makes sense and he worked on a whole fleet of 4.0's for over 5 years. Just food for thought.
BTW< my 1990 with 150K usually cranks for about 2.5-3 seconds before it starts.

Good luck!