YJ still not starting

[wadesbrain]

Well here it is again. I still havent figured it out so I thought I would throw it out again. MY '94 YJ 2.5L isnt starting in the cold. It is currently 34 degrees outside and no sign of life. Here is what Ive done so far: new battery, plugs, wires, cap rotor, fuel filter, and coil. Ive tried using the fuel line antifreeze too. It is cranking fine but just doesnt seem to start. Once it actually gets running it is fine and will start as long as it hasnt cooled off too much. Any ideas?

 

[yjdave]

RE: Gain 50hp and 72ft/lbs of torque with household items

check your fuel pressure at the fuel rail, maybe the pump isn't up to snuff, also if you have a bad crank sensor you'll get no spark..........

 

[mud4feet]

Google "Jeep crank postition sensor"........interesting reading - lots of folks with problems similar to yours. Replacing CPS seems to be the cure.

 

[wadesbrain]

it warmed up enough yesterday and today to get it started. yesterday i pulled out the cps just to have a look. No obvious damage noted ( I know that doesnt mean anything). After putting it back in and messing with a few other things (that probably didnt do too much), it started. but now there is a new problem. It runs fine and then for no reason just quits. Both at idle and while driving. I put the computer to it and it isnt showing any faults. I'm sure it could be the cps but wouldnt that show up when checking faults. It almost seems like the ignition is being cut off. Is that how the cps would react?

 

[wadesbrain]

2000 XJ Rough Idle

Im going through the same thing right now on my 94 yj. I just read somewhere (sorry guys not on this site) if the tach doesnt show any rps while cranking then it is the cps. dont know it it is true but im going to check it on mine. Ill probably replace it anyway. let me know if you find any solution.

 

[wadesbrain]

just replaced the cps. no luck. still not starting. i do smell gas though when i crank it for a little while. any other ideas?

 

[mud4feet]

The infamous gas tank sending unit problem on 97 TJ

man, i'm lost, and sorry for the bad advice....thought i could help. i was thinking maybe coil, but you said you replaced it, too. my "old school" thinking is an internal combustion engine needs 3 things....fuel, air, and spark. sounds like you've got 2 outa 3....sounds electrical but my computer skills end at the PC. wish i could be more help......keep us posted.

 

[TwistedCU]

RE: 2000 XJ Rough Idle

Probably a long shot but could you possibly have water in your gas?

 

[wadesbrain]

I ran thru a bottle of drygas and then filled up with super. then ran a second bottle and its on the second tank of super. if i can get it running at least a little more consistantly i want to run through some seafoam. Any experiance with that stuff? I've heard it is good stuff but you have to replace your plugs and filter afterward.

 

[TwistedCU]

Re: RE: Wait till your father gets home

Never heard of seafoam. I don't like the idea of using liquid fixes personally whether they be in the gas, the oil, radiatior, or anywhere else.

I got a tank of bad gas (pump ran out while I was fueling up - I knew it meant trouble) in a dodge once and ended up having to drain the tank. May not be your problem but I thought at this point you're ready to try just about anything.

 

[Sparky-Watts]

RE: First time Off-roading

Yeah, if you've got a lot of water in the tank, a couple of bottles of Gas Dryer won't help at all. You may want to check into that.....

 

[djak12]

RE: Yea the super bowl is over!!

I know that you stated that you changed the coil. Not to seem smart but are you sure that the coil you replaced is also good? The problem that you are having is the exact problem that I had when I swapped out my motor. The motor would start and run when it wanted to. it made no difference on the temp or anything. I tried everything. The same problem as you stated no computer errors. I am thinking you are having the same problem because it will not show any computer errors because it is not part of the computer system. I would recommend checking the coil as well as the connections to the coil to make sure that the terminals do not have a break that you can not see. I hope that this helps it drove me crazy until the last time it broke down I was near a friends house that also had a mechanic near by and in 2 min he had a "Hot Box" hooked up to the coil and told me to replace it. Every since I have not had a problem

 

[captainhook2]

RE: Paragon Feb 19th

It is your choke. the 4cyl are known for not working properly. Use an ohm meter to see if you are getting power to it, and if you get desperate install a manual one.

 

[_(OIIIIO)_Jeeper]

RE: Another Set Back!!!!!!!

SeaFoam is a great injector cleaner. I have used it before. using the 1/3, 1/3, 1/3 method. put 1/3 can into your tank, 1/3 can into the oil(cleans the sludge) and pour 1/3 directly thru the injectors...i put mine thru the brake vac. hose......you have to pour it slow...it will choke down but try to keep it going, then shut the engine off for 10 min. start it up and drive AWAY from town for about 10 miles...it will smoke like a freight train and probibly run on 1 cyl! after about a mile or so it will pick up the other cylinders and stop smoking by the time you get back

 

[Sparky-Watts]

RE: Chat site problem

SeaFoam is a great injector cleaner. I have used it before. using the 1/3, 1/3, 1/3 method. put 1/3 can into your tank, 1/3 can into the oil(cleans the sludge) and pour 1/3 directly thru the injectors...i put mine thru the brake vac. hose......you have to pour it slow...it will choke down but try to keep it going, then shut the engine off for 10 min. start it up and drive AWAY from town for about 10 miles...it will smoke like a freight train and probibly run on 1 cyl! after about a mile or so it will pick up the other cylinders and stop smoking by the time you get back

Dang...I don't know if I like the sound of that....a guy I used to work for would pour ATF down a carb on a running car and fill the entire shop with thick white smoke in a matter of seconds....always hated it when he did that. He swore it cleaned the carb, intakes, etc, but I never could tell much difference in the way the cars ran afterwards. They usually ended up getting a carb overhall anyway.

 

[_(OIIIIO)_Jeeper]

RE: Changed to synthetic blend oil, should water temp drop?

The Honda Motorcycle Dealership I worked at we recommended it alot to customers who could not afford getting their carbs cleaned. It IS NOT a miracle cure. but over time (say 6-8 months) of use it does clean carb and injectors to a noticable differance. Now I'm talking about units that would not idle, faultered when given gas sort of thing. We started using it from the recommendation of an auto tech that used it in his shop...one of the most noted shops in our town. this stuff is not ATF

It was just a suggestion....

thick white smoke in a matter of seconds....always hated it when he did that

:wink: Yeah it will smoke up the area!

 

[wadesbrain]

stock rim size

ok here is what i have so far. still no go on keeping this going. I am pretty sure that it is an ignition problem and not fuel related. If i crank it long enough i start to smell gas which tells me that it is moving somewhere. I havent tested the pressure at the fuel rail though. (if someone can tell me how I'd appreciate it.) I just ordered the powertrain diagnostics procedures manual from a guy in MA. He seems friendly enough and he had the manual when chrysler didnt. here is is link in case anyone else is looking for rare manuals:

http://www.autopaper.com/index.shtml

in the meantime ill start checking wires and hoses for wear/shorts. I may also rip out the alarm system. It is an aftermarket and I have had problems in the past with those things. Im still open for suggestions though.

 

[yjdave]

RE: SYE Question

Go rent a fuel pressure gauge(or come by my place..lol) and put it on the little tire valve looking thing on the fuel rail and check the pressure. You need to check it while its running to. You might only have enough to start but not to keep it running. The mpi systems take like 95psi or more to keep running. The kit should have directions on how to check it though....good luck

 

[Sparky-Watts]

Man, if you can't get it running at all, how would you ever check the fuel pressure? I know my '94 YJ shot a stream of gas about 20 feet when I was changing the filter back by the left rear tire....plenty-o-pressure there!

 

[wadesbrain]

ive had it started but it wont stay running. the last time it ran it sounded good but after a mile or so it quit for no reason. then it was hard to start once it got going again it quit after driving a few blocks then followed that pattern for a little while. i parked it that day (last sat) and havent touched it since (because of work). im going to check the pressure on the fuel rail and see what it says.