Hard to start if...

[BIG]

Hey all - I'm back......... had a little more work done on the back and finally feel great! Anyway, the YJ is having some hard starts when left out overnight when it is getting cold. If I garage her overnight she starts fine, but if left outside it takes a bunch of tries to get her to the point of a rough start, then she runs great. Now even after being outside at night for 4 hours it is a real rough start... All that said, what parts / components would be effected be the colder temps or the damp evening dew? One last point - when she sits all day at work, no problem starting - just seems to be at night or overnight outside???

Could this be CPS or something in the distributor? Fuel issue? Help.....

BIG

 

[beaker]

Are you getting any error messages?  That's a tough one.  Try cycling the key a couple times form off to on instead of trying to start it.  That will cycle the fuel pump.  If it starts better than that's likely where the problem lies.

 

[BIG]

will try - no check engin light comes on when she is running.....

 

[Rubi04TJ]

CPS is either good or bad. So if it starts it is fine. When you are trying to start it, push the accelerator to the floor and start it, should start right up fairly quickly.

My two four bangers had this issue and i was never able to figure out why. I change throttle bodies and sensors and nothing worked.

 

[cowboyupdan]

could it be a bad ground someware that gets worse when damp?

another guess would be too much condinsation in the fuel.

 

[kakirubi]

If I garage her overnight she starts fine, but if left outside it takes a bunch of tries to get her to the point of a rough start, then she runs great. Now even after being outside at night for 4 hours it is a real rough start...

I had a girl like that once!

 

[BIG]

So I am trying to rule things out one by one - yesterday I hooked up a fuel pressure gauge and get 30 psi with the key on. I left the gauge on overnight and it was at 0 psi this AM - when I turned the key to the on position it stayed at 0 for a second and then I hear the relay kick on (clicking sound) and it jumps up to 30 psi - but takes 3 or 4 tries to turn over and "catch"...... Plenty of power to turn over and over and over, just a real rough sputter and then finally will start - then runs FINE....

What should the fuel pressure hold at overnight - and how do I determin if it is the fuel pressure reg (I checked to see if it was leaking by unplugging the line and leaving a piece of paper under it to see if it was leaking - but it seemed fine), or the fuel pump that is causing the lack of pressure.....

Again - a 94 with a 4 banger.

 

[massxj]

just a guess but the injectors could be leaking down over night.  dunno maybe. try some seafoam or somthing like that to clean the injectors and see what happens

 

[beaker]

If after the pressure has risen to the 30 psi and the truck is still hard starting, check the plugs, see if they are fouled. I'd try new plugs too (they're cheap). Plugs can go bad (internal cracks etc).

 

[BIG]

So I am staill having trouble with the YJ - starting can be an adventure.

1 - when I turn the key to the on position sometimes the "check engine" light does not come on, and that is followed by not starting no matter how many times I turn over the engine. If I trurn the key and see the check engine light I usually have no trouble starting - maybe here a relay cycle on and off a few times but she will start OK.

2- Fuel at the rail is ~30 PSI when I get the check engine light.

What controles the check engine light?

what controles what from the ignition to the computer to the relay and fuel pump... I am at a loss - and have had somebody reccomend a new computer - at $500 !!!!!! OUCH.

Any ideas - thoughts on where I can get a computer for less if I go this route - dealer or shop close to Shelton area you trust?

 

[MasterDrazhar]

Try getting a computer from a bone yard.

 

[JeepinMaxx]

Try getting a computer from a bone yard.

I got an ECU for $100 at Arite in Berlin, use it to troubleshoot a bad CPS and then returned it for $100 store credit (like I couldn't fin $100 worth of Jeep stuff I wanted there :wink


FYI
Arite Used Auto Parts
124 Christian Ln
New Britain, CT 06051
Phone: 860-224-9920

 

[beaker]

Hit autozone and have them read the code.

 

[BIG]

Just getting more and more odd....

Turn the Key to the on position - nothing happens, no increase in fuel pressure or anything - wait 20 seconds to a minute and then the relay (fuel pump) starts clicking, the check enging light goes on (flashing on and off a few times befor staying on), and fuel pressure jumps to ~35 PSI and it will start right up -

Also throws a code for a bad AC relay - but there is no AC in this Jeep?

Starting to sound more and more like a bad ECM/computer - anyone have other ideas?

 

[gorilla_skater]

If Autozone read the code, look it up on the internet. Don't trust their database. They said the code they read on my XJ says it had a TURBO!

 

[JeepinMaxx]

Here's the link to the codes I've used for the Dakota, YJ, and recently KJ (and soon on the Magnum)

http://www.allpar.com/fix/codes.html

On YJ's (and pre '96 XJ's) - to get the codes- turn the key from off to run (not start) 3 times in a row - then count the flashes on the check engine light.

The link explains all the different ways to access codes on mopar PCM/ECU's

Hope it helps

 

[BIG]

Just think Johnny Cash - "I took it one piece at a time".... so I am at wits end with my 94 and the starting issue - cannot find a ECM around here for under $600... so I give Bill at SVE a call and he said he had a ECM from a 93 - and I was welcome to come and get it to try and see if it would work - even though it is marked with a different SKU... So I stop by to pick it up - and he does not ask for any money - "just take it, and if it works pay me, if not return it".... and it works.... starts like a charm and runs like it used to. :lol:

Jeep people never stop surprising me...

now for a new rear diff and gears.....