Crank, but no start

[scrambler013]

My 95 YJ will crank but not start. :cry: I have fuel pressure, spark, the timing isn't off, and everything seems to be working fine. I think it may have to do with a bad sensor somewhere but I am not sure which one. Anyone with suggestions please feel free to offer them up. Thanks.

[Blupupher]

I would agree with a sensor problem. Is it running at all, even for a second, then dying? Or just no start at all? I know those engines are notorious for a Throttle Position Sensor going bad, but I am not sure on how to check it. Sorry I couldn't be more help.

[scrambler013]

Thanks Blupupher. That acctually helps more that you realize. I didn't know they were known for bad TPS's. I will try to replace that and see if it works.

Thanks.

[1981CJ5]

HOW DID IT DIE OR WAS IT RUNNING GOOD WHEN YOU SHUT IT OFF

[Blupupher]

Also is it a 4 or 6 cylinder?

[scrambler013]

The engine started but as soon as i touched the gas pedal it started to idle down, then just shut off. The gas tank is almost full and there is no water in the gas. It has a 2.5 4 cyl.

[1981CJ5]

IS THE CHECK ENGINE LIGHT BLINK WHEN YOU TURN THE KEY?IF SO COUNT HOW MANY TIMES AND LOOK IN THE OWNERS MANUAL AND LOOK UNDER TROUBLE SHOOTING AND IT WILL TELL YOU

[Blupupher]

Sounds like the TPS. If it idles fine but dies when gas is given, is is a fuel problem. Have you checked the fuel pressure when you give it gas? If it goes up (I think around 32 psi, but not positive) it is ok, Probably the TPS. If it drops immediatly, possible something with the pump.

[scrambler013]

The only time it died was the first time i tried to start it. since then it hasnt even started. It will crank but it wont turn over. The check engine light hasnt come on either. I am going to have to get a fuel pressure tester tomorrow and check it. Hopefully that will give me some answers.
Thanks for all of the input so far. It has helped out a lot.

[Blupupher]

.... It will crank but it wont turn over....
OK, These mean the same thing (at least to me they do).
So the starter turns the motor, but nothing more than that happens, correct?

[blkhawk556]

:USA: this may sound stupid what about your fuel filter, also in the haynes and chilton's manual there is a detailed list of trouble codes and how to check sensors

[scrambler013]

The engine turns but will not fire. I have checked the sensors I can with a scan tool. I have eliminated the TPS and the IAC. I have to agree that it may be the fuel filter. I am going to replace it tomorrow morning along with the plugs, just in case i have weak spark at the plugs. If that doesn't do it I am not sure where to go from there.

[DeckDog]

another posibility is the relay from the ignition, I had a similar prob once where it would cranck and sound like it wanted to start but as soon as i let the key go it would just die...... it's a simple check and cheap fix it that's it..

other posibilities are the cps, the hall effect triggers that are use can be tempermental, also the tps or the pump.....

Good luck

and lets us know what it was

Timothy

[scrambler013]

Well so far no luck :cry: . I have checked all of the sensors i can with a scan tool, replaced the plugs, checked wire resistance. All to no avail. I, at this point am at my wits end. But I REFUSE to take it to a garage. NO ONE TOUCHES MY JEEP!!!!!!!! But me and fellow Jeepers. I haven't put a new fuel filter on it yet (no garage at my house and it is too cold here in Erie, PA) and of course i cant drive it anywhere. I will post something as soon as i get closer to the solution. Thanks again for all of the input :)

[Joker®]

Sounds like there's no juice to the plugs. Have you checked the plugs for a spark? If the wires are good, check the distributor cap & rotor then move toward the coil.

[Albatross1950]

How long has the gas been in the tank? If it has been more than a few months, try putting new gas in the tank.

[moabe]

PULLL THE HOSE OFF THE FUEL FILTER AND TRY TO CRANK IT... NO FUEL EQALS BAD PUMP, ALSO YOU HAVE A FUEL RELAY IN THE FUSE BOX... you start jacking with the tps and its a pain to get positioned correctly... im bettin clogged strainer at the fuel pum...goood luck droppin the fulll tank... 8)

[scrambler013]

I put a new fuel filter on the other day, it wasn't clogged but I replaced it anyway. That didn't solve anything. I will try pulling the hose and cranking but I do hear the pump turn on. The tank isn't that hard, I put a new one in my wifes Cherokee on sat evening. It took 2 and 1/2 hours with hand tools and no car lift. The only thing worse on the Wrangler is that damn skid plate. Other than that it's no problem. I worked as a mechanic for a little while and can do most basic stuff, but drivability like this was my worst nightmare. I still can't do it. I even have my own brand new OTC scan tool. Pulls codes from all american models. All the way back to 92(i think) on the Jeeps. But that stinkin' Wrangler has, for lack of better terms, got me by the balls. :oops: I will get it one of these days.

[scrambler013]

I think I may have found the problem. The ignition coil resistance is reading like this. Primary side: 1.2 ohms, Secondary side: 10.43 Kohms.
The book I have says that is out of spec, is there anyone who can verify that for me, I have found that the book I have has been wrong on a few times and want to be sure. Thanks.

Matt

[Joker®]

Scrambler013, here's what I dug up.

Diamond
Primary: .97 to 1.18 ohms
Secondary: 11.3K to 15.3K ohms

Toyodenso
Primary: .95 to 1.20 ohms
Secondary: 3K to 10K ohms

Hope this helps & good luck.

[scrambler013]

Thanks for the info. Howver replacing it didn't help. :cry: I am replacing wires and testing fuel pressure sometime today to see what is up there. I hope to have it running by the end of the week.

[scrambler013]

OK now I am getting somewhere. The pressure in the line must have been residual pressure. I put a tester on the shraeder valve and with the key on engine off, I have NO fuel pressure. I think that is a bad regulator. I don't want it to be the pump, but I have a bad feeling that it is. So finally after all of your suggestions I have gotten somewhere. Thank you everyone who has helped out. Even if the suggestion isn't getting to the root problem, they helped eliminate stuff. Thanks again, I will keep posting as I progress towards the successfull completion of the task at hand.
Think it may be the pump, No fuel pressure at all, but the pump turns on. I may have a clog at the pump pick up in the tank. Going to try a few more diagnostics and see if that is right.
Matt

[sanduskyj]

I don't know if you all ready have check this but, I just had a similar problem on my 95 YJ and it turned out to be a bad ground to the engine blcok.

[scrambler013]

Thanks I will look into that before I go replacing the fuel pump. Where was the bad ground at? Just to give me a place to start

[sanduskyj]

right by the starter on the engine block.

[scrambler013]

ok ty Ill start there Thanks

[thejeepingoat]

from what i learned in auto-mechanics, good place to start is spark.......you can do this by pulling off a plug wire and holding it cloe to something metal, bout 3/4 of an inch away, if it can jump that gap, believe me you have nothing to worry about there....then all other electrical systems....next thing is fuel and fuel delivery, when u first turn the key........u should hear the fuel pump turn on.......i do not know if jeeps have this, but i know fords do, there is a switch, that if the vehicle flips over or is a horrible crash it will trip and not allow fuel to the engine, it will crank all it wants, but it will never turn over, this switch on some fords is near the firewall on driver side under everything....it is common to hit this switch while doing something under there and just jiggling it......all u have to do is unjiggle it....i do not know if jeeps have this, but i think it would be reasonable to have because what one would put a jeep through,the possibility of a flip is there.......your not done with fuel yet, i would rule out anything with fuel before movin on.........the next thing is compression, which i know is not good to find out that you do not have good compression....they are easy to run...just place the compression tester in place of a spark plug and let it crank. i know you will probably have this problem solved when u read this, but hey, any information is always useful
-goat

[scrambler013]

Thanks for the clear instructions goat. I also have worked on cars in the auto industry. I know what you are talking about with the fuel switch. I worked at a Ford dealership. I have ruled out the spark, I have it. I think it is either the fuel pressure regulator or the fuel pump sock is clogged. If that doesn't solve it then it is most likely compression. If that is the case does anyone have a used 4.0 for sale. I can rebuild it if needed. :D Hahahahaha. I will look and see if Jeeps have that switch you refered to, I don't think they do, but I will look and see.

[thejeepingoat]

it slipped my mind and i couldnt think of the name of it, but im pretty sure its called an inertia switch, it was on my mind since the second i posted......good luck, and sorry no 4.0's here.....
-goat

[Big Buro]

Mr. SCRAMBLER013!!!!!!
WHere are you with this thing? Have you gotten it running yet? I'm sure that I'm not the only one curious.

See there, got it right this time.

[scrambler013]

I am still kicking it. #&(*!^^(*^$#*%)&_**^^$@! YJ! I have replaced, here is the list.
1) Plugs
2) Wires
3) Ignition Coil
4) Fuel Filter
5) Fuel pressure Regulator
For my next trick I am going to make it dissapear! :D I am going to check the timing this week, and the grounds on the engine. I will most likely have to put a new battery in it too. What was that about Old Vs. New? :g Saturday I am driving to Hershey to visit the Rents, so I won't think about it(yea right!) I hope it isn't the timing.
Oh yea I also checked the fuel pressure, It is good. HELP! :(
:x Stupid F&(*%^ computer controlled engine. :x

[Big Buro]

Well, I'll be damned if I'm not stuck. I read all of the other posts and figured for sure you had to get it by now. I wish I could help but, unfortunately, if it's not a CJ I'm lost. If this doesn't just put a cap on that whole "old vs. new" conversation, I don't know what does.
Riddle me this though, how could it be the timing? Also, Isn't that thing supposed to provide you with some sort of code when there's a problem? I'm willing to bet it's got to be one of three things (and you seem to have covered all of em' so I'm going out on a limb here) it's going to be fuel, spark, or one of the stupid a$$ed sensors. I can't see it being the timing. Not just out of the blue like that. Also, behind it all, it's a jeep for christ's sake, it's got to have something left over from the good ol' days. I think you may have to break down and have it looked at. I hate to say it but it seems to me that whatever the hell it is, it's hiding awfully well. I wish you luck and keep me posted. (Keep us posted that is)

[scrambler013]

The reason I am checking the timing(haven't done it yet this morning) is because, for now, I am following the Haynes repair manual troubleshooting list. It suggested checking the timing chain. It is quite easy to do. Set the engine at top dead center, pull the distributor cap off, make sure it is pointing at the #1 plug. Then you turn the crank shaft two full turns and check to make sure the rotor is still pointing in the same spot as before. Please don't let it be a sensor! F@(^$*g computer controled engines. :evil:

[Big Buro]

I suppose timing could come into play but it just seems odd to me out of the blue like that. On these computer controlled engines, is the timing also controlled by this same computer? Well, I can tell you what type of jeep I'm NOT going to be getting any time soon......

This is beginning to peak my interest, I think I'll do some searching to see if I can't locate some possibilities. I've got a few connections out here in California that work on the newer jeeps. I'll let you know what, if anything, I can find out. Let us know how that timing check goes.

[scrambler013]

Remind me why I like working on Jeeps. I am absoulutly stuck! The timing is good, I also checked the grounds on the engine, all good. The battery is good, it is holding charge and is just under 12 volts(that is because I have been trying to crank it). The starter is starting to sound slow. I have a mean green starter I need to put in yet, the positive battery cable is too short. I may try that and see what happens. If anyone knows how to check individual sensors by themselves please help. I checked with a scan tool but on the 95's my access is limited. It isn't even OBD2 yet. I looked and I can't see a crank or cam position sensor. I can see the TPS and IAC. I don't even know if I have a CPS on that thing. All of these sensors are making my head spin. :x This is really making me mad. I think I will go out a take apart the engine from the CJ-5 to prep for rebuild. There aren't any sensors on that thing(thank God).

[Big Buro]

SO, I talked to the guys at my local jeep place and once I convinced them that you weren't gonna take it to a mechanic, they basically said you're screwed. As far they know, only a mechanic has the "equipment" to locate the sensor that's causing the problem. By the way, both mechanics think it's definitely a sensor. TPS is what they're saying but haven't you checked that already? Anyway, I'll keep looking for ya, just keep plugging, you'll get it eventually.

[scrambler013]

I GOT IT! It was that damn TPS. I finally said screw it and went out and just got it. Sure enough as soon as I was finished I jump started the YJ and it Came to life. It Is ALIVE!!! :D . So now I have a YJ and a TJ to run around town in. Weeee I got it running again 8) . thank you everyone for giving me input. It has all helped. Now we can ignore this topic.

[Blupupher]

Hmmmm,TPS sensor, sounds familiar.
from NOV 14 (first reply)

I would agree with a sensor problem. Is it running at all, even for a second, then dying? Or just no start at all? I know those engines are notorious for a Throttle Position Sensor going bad, but I am not sure on how to check it. Sorry I couldn't be more help.

Well, I am glad you finaly got it working.
And as to why you like working on your Jeep, this is why, YOU fixed it.

[scrambler013]

Yea I know, that goes back to my thick headdedness from one of my other posts. You weren't the only one that said that. I should have listened back then, but there is that thick head again. Thanks again to everyone who posted with helpfull suggestions, even if it took me a while to use them :oops: .

[LeadFoot]

Glad to see you finally got it running.

[Big Buro]

Well, I'll be a son of a gun. That's great!
Blupupher had it right all this time. Good call Blupupher!!!!

And, Scrambler013, that thick headedness is why you're so damn happy right now. Had you taken it to a mechanic, and they fixed the TPS, you'd be kicking yourself ALL THE WAY HOME!!!! I find that, sometimes, being thickheaded or stubborn is one Hell of an asset.

Great job...

[Blupupher]

Well, like I said, they are known to be bad, some people even carry a spare with them. Man this makes me look like I know what I'm talking about. Scarry. Again, congrats on getting it running.

[thejeepingoat]

Good Job, glad its up and running again, and in the process you probably did some stuff that you should have done anyways, so thats good....happy wheelin'
-goat

[extexan]

scrambler013--glad to see you found the problem. this topic has really helped me with my 95 YJ 4 banger. figured out things i should be taking a look at a little bit closer. get wrapped up in mods, but need to focus on a good running machine first!!!!!! once again glad you got it running :lol:
extexan

[scrambler013]

Yeah I did some stuff that needed done. Fuel filter looked like it was about to rust through, kinda plugged too. The plugs were fouled up a little and the plug wires were out of spec on resistance a little. There were some other things I should do next, but I am driving it down to my friends house and doing it in their garage. I got the stainless hinges for the windsheild, the mirriors too. I can't wait to get started on the projects that I have sitting here in the driveway. But now that that is all done I can move on to better things :D .

[sbacon]

TPS sensor


Well, I am glad you finaly got it working.
And as to why you like working on your Jeep, this is why, YOU fixed it.

I was going to say that...LOL Glad to hear you got it running!!!!! :17: