UPDATE Tks Sawduste & QUE89YJ
A question asked over and over with a twist. 70*F cold start problem?
"I know this question has been beat to death But I have yet to find a good answer to it ,lots of guesses and I thinks or this is bad but I have not replaced it to see if it is really the underlying problem !! So here go's 1995 wrangler reo grande 2.L 116.000 miles bone stock except new timing gear and chain with new tensioner. Even at 70 degrees F this little motor has a cold start problem if you would call it that I don't see 70%F being cold but it is the first start of the day. I go to start my 2.5 and it stumbles, high idle,stumble again catch it self just before it stalls several times. tack shows as if the key is being turned off then back on when it is doing this, at first cycling the key several times and allowing check engine light to come on and go back out helped. but at a air temp of 70%f + I don't consider that COLD Maine is cold but not summer time, Now I was just up in northern Maine 3 hours from me and it was like in the W's at night and mornings After cycling the key 7 to 10 times the 2.5 would start BUT still stumbles, high idle no idle check engine light flashes, Back to high idle, back to like someone shut the key off. several more cycles of the key It might stay running it mite not, It might still stumble it might stay running. I don't touch the gas pedal at all due to it will not help the problem, 2.5 has new t-up 100% complete including fuel filter There seems to be a lot of guesses on this topic and comparisons to other engines I am talking 2.L not 4.0 or any other I searched this thread and was unable to find an adequate answer. Someone has had this exact problem and knows what the fix is !! Not a i think or I would guess, or try this A real answer this is a Jeep forum Right ? so if you know the fix for this Maybe its time to share It may have cost you but that doesn't mean you have to keep this information to yourself Pass it on if you have the knowledge Help out fellow Jeepers" QUOTE
I have been several weeks attempting to solve and fix my cold start issue, The first response I got was from Sawduste He suggested I needed to change my fuel pressure regulator and I did That solved my cold start problem for 3 mornings. Then it became harder to start I had to cycle the ignition 4 to 10 times to get it going. and stay going, other than that it would stumble catch itself then stumble again with all lights coming on just before it stalled.so there is one bad regulator from O-Riley auto parts Bleed down was way to fast, it would not hold any pressure. I had just did a 100% complete t/u so I knew all was good there. From what I have been told Sawdust is not doing well health wise And I wish Him the best " we need your knowledge Dude" From what I understand he knows his sh&% so hopefully you will get better soon. And Thanks to Query he spent 4 days on the phone with me, :thumb sup: he spent the time to help get my 95 Y's issue fixed. "It's A Jeep Thing"
We started of by checking fuel flow, This is done by cycling the ignition several times with the Shrader valve removed and a hose hooked up To valve neck and a container to catch fuel . Now I had results of : like a old dude: umbrella: first just a dribble then a squirt, and to finish it a small amount to add up to about a half a cup
not enough your fuel pump only runs on start up for several seconds and your check engine light must come on if not you have a PCM with bad compositor's only 3 and can be replaced with some soldering. OK again Thanks have to go to jeep guru Que89YJ for him spending his time to help get my YJ so things with the fuel system were operating properly. First thing was a fuel pressure test witch for a 2,5L mpi should be 31 to 32 w/ vacuum line plugged in on regulator UN plugged 41 to 42 as for leak down test leave the fuel pressure gage hooked up to see how long and at what reading it stops at normal would be 20lbs to just under for 20 + minuet's this tells you if you pressure regulator is doing its job. you can pull your fuel pump relay and run a jumper wire to the two center terminals #30 and #87, # are on bottom of relay this will give you a fuel pressure reading with out having to turn on the key , if your pressure is low you pump is bad, if your pressure is high you have a plugged , pinched or kinked return line, One way to tell to be sure is to unhook the regular line from the fuel rail check your pressure by jumping the relay terminals just long enough to reed fuel pressure I got 40LBS then a drop to 31 or very close to it. Now I also replaced my sending unit complete with pump from O-Riley. when I installed it I had to push it down to start the bolts
Not good by doing so you plug off the return witch will give you 55 to 60 LBS on your gage not good que89YJ said to remove the plastic pan that the pump sets in you can just pull it out and toss it, It gets warped and can hang up your float and plug off your return example the after market parts, be sure to check the pump mounting bracket and rubber seal on bottom of pump mine was bent and the rubber would not seal allowing fuel to not be able to pump full pressure swap out your old one from your old pump if you have to. the reason I had to replace the whole sending unit was because my fuel feed and return nipples had pin holes in them And it was only like $40.00 more than just a replacement pump
. now very very important the rubber lines that run from the metal line's to your sending unit absolutely must have no sharp bends or kinks at all and to replace these lines you will need to loosen 3 body mount bolts being careful not to brake any off I found these lines soft, warn, and cracked, you need be as close to the same length as original and they are both 5/16 high pressure line, you will find the main feed supply line fitting on sending unit is larger than the return a blow dryer will help with getting that line on by heating it
A little oil one lines will help them slide in easer Thanks to que89YJ for keeping me from
and pulling my hair out, step by step he talked me through it all explaining what was right and why things were wrong, and how they work, what happens when a part is not operating as it should, And what to do to correct it
The one thing to keep in mind is have a pressure tester before you start and start testing before you do anything, don't rush to put your tank back in, I took mine out 3 times
make sure if you replace you pressure regulator install first 0ring the small one in housing alone using a small amount of oil Make sure it is seated evenly, then install regulator if not you can damage the small oring "A little oil go's a long way" don't change more than one part with out doing tests this way you will know what if anything changes for bad or good. If you talk to Que89YJ listen to him he knows his jeep's
I cant express enough that test ,test ,test And if there is a ? Test some more Remember !! Fuel flow, Fuel Pressure, your check engine light coming on and no kinked or plugged return lines. Also keep in mind a supply of fishing gear
If you have any question's about any of this you can contact Que89Yj or if you want to talk to the guy that can take out a tank with his eyes closed give me a hay Zombiepirate. I hope this helps some one some where some time, But if nothing more it is knowledge