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-   -   Cylinder 1 misfire, please help (http://www.wranglerforum.com/f210/cylinder-1-misfire-please-help-180839.html)

lightningdan 08-16-2012 12:37 PM

Cylinder 1 misfire, please help
 
Hey guys let me first say I searched the forum and found a few answers BUT it only leeds to more questions for me, so I figured I'd post hoping someone will guide me so here's the deal

Last week my girls jeep threw a check engine light, had it scanned misfire cylinder 1. Jeep is a 99 wrangler, 5 speed, 6 cylinder, 154k on it

I bought new plugs wires cap rotor, ( plugs are platinum which I learned isn't good) anyway I installed them, keep was like brand new ran great! 3 days later she got stuck at work it was like someone played a joke and crossed the plug wires, thing wouldn't idle Falling on its face, so call AAA

About 45 minutes later she tries to start it and it stumbled she reved it to 1500 for 45 seconds and bang! It was fine, been good for 2 days

Now as we speak I get a phone call, check engine light is back on and she had it scanned same code, misfire cylinder 1

Now I am guessing it's either the cam sensor or crank sensor, but what I learned in back searches is ( I'm guessing) if u replace these sensors u need the computer reflashed?

Is this true? What would u replace first and is there any walk threws on changing the cam sensor and or crank? I read the cam sensor is under the distributor disc? Anyone have any pics?

And again any help is greatly appreciated, thank you!

Danny & Amanda

needforspeed150 08-16-2012 01:48 PM

I noticed that no one had chimed in on this one but if it is cam sensor or crank sensor they have to be installed and adjusted correctly. I wouldn't see why a reflash would be needed if installed and adjusted correctly. Might just take a compression test on #1. hook a timing light up and maybe you could see how often it is missing. Don't take this as law but I'm a single guy with 7 cars and to motorcycles so I do most of my own repair.

tangofox007 08-16-2012 02:17 PM

Quote:

Originally Posted by lightningdan (Post 2690937)
Now I am guessing it's either the cam sensor or crank sensor...

What is your theory on how a cam or crank sensor issue could affect only one cylinder?

lightningdan 08-16-2012 05:03 PM

Quote:

Originally Posted by tangofox007 (Post 2691258)
What is your theory on how a cam or crank sensor issue could affect only one cylinder?

Well I have a little back ground in EFI systems, I converted over my drag car to accell DFI gen7, and learned allot on how that system works, and with that system, the vehicle will fire until it picks up cylinder 1, once the crank sensor determines cylinder 1, we have lift off

The other night when she was leaving work, it would sit there turning over and wouldn't fire... Like it had no spark, it sure did have fuel though

Then while after a 35-45 minute wait she attempted to start it and it was hiccuping and she got it going, revving it to 1500 cleaning itself out, I figured all that time trying to start it the plugs were fowelled because I could smell gas really bad...

I'm guessing it's the crank sensor, I am going to install one tomorrow, jeep has 154,000 on it so I figure it wouldn't hurt

I honestly don't know the job of the cam sensor in the jeep, my DFI setup doesn't use a cam sensor, before I read more back searches I was wondering when people posted cam sensor, and crank sensor, if they were meaning the same thing, because with most fords it's either a crank sensor or a cam sensor, we don't use both, heck early fords don't use them at all lol

lightningdan 08-16-2012 05:07 PM

Quote:

Originally Posted by needforspeed150 (Post 2691162)
I noticed that no one had chimed in on this one but if it is cam sensor or crank sensor they have to be installed and adjusted correctly. I wouldn't see why a reflash would be needed if installed and adjusted correctly. Might just take a compression test on #1. hook a timing light up and maybe you could see how often it is missing. Don't take this as law but I'm a single guy with 7 cars and to motorcycles so I do most of my own repair.

I try and do all my own wrenching as well, even though it's getting harder and harder to do with all these computer systems... And even now with the introducition of black boxes...

Thank you for advice, is there any special way of installing either? I did read a back post on how someone used a after market crank sensor and it smashed up against the flywheel...

I just got back from the shop and my friend who does trannys for a living did a crank sensor on his boss' jeep! We are going to tackle this tomorrow he was explaining to me how the cardboard at the end is a spacer. I would like to see how other people did it though just to double check his method

I appreciate it, thanks for the response!

lightningdan 08-17-2012 07:58 AM

nobody else has any info? or suggestions?

HarryJeepGuy 08-17-2012 08:56 AM

Any other symptoms? Is it hard to start? Blowing out a white cloud on startup? Exhaust smell like gas? Oil smell like gas? Oil level increasing/high? Is #1 cylinder spark plug fouled way more than the others? No pressure on fuel rail shortly after turning it off? If so, could be a bad #1 injector.

lightningdan 08-17-2012 05:14 PM

Quote:

Originally Posted by HarryJeepGuy (Post 2693825)
Any other symptoms? Is it hard to start? Blowing out a white cloud on startup? Exhaust smell like gas? Oil smell like gas? Oil level increasing/high? Is #1 cylinder spark plug fouled way more than the others? No pressure on fuel rail shortly after turning it off? If so, could be a bad #1 injector.

Thanks for the response, I am leaving my house as we speak to go to the shop, I am installing a new crank sensor, and checking number 1 to see if it's gapped correctly, I read .35 sould be good

Everything seems fine, it even runs and drives fine?! When it threw the light it didn't even hiccup it just came on, a friend of mine also said he would change the injector

I'll post back tonight with the gap of the plug that's in the now, I didn't gap them the auto parts guy said they should be good, I know I should have check that's very poor on my hand... But I seriously doubt that's it, but u never know

Where can I get injectors? Or should I say where can I get 1 stock injector? How much do they run at the dealership?

Thanks for the advice, I was getting afraid people were forgetting about me :)

Please don't mind my spelling my iPad is auto correcting everything.... Errrrr

HarryJeepGuy 08-17-2012 10:34 PM

Quote:

Originally Posted by lightningdan
Hey guys let me first say I searched the forum and found a few answers BUT it only leeds to more questions for me, so I figured I'd post hoping someone will guide me so here's the deal

Last week my girls jeep threw a check engine light, had it scanned misfire cylinder 1. Jeep is a 99 wrangler, 5 speed, 6 cylinder, 154k on it

I bought new plugs wires cap rotor, ( plugs are platinum which I learned isn't good) anyway I installed them, keep was like brand new ran great! 3 days later she got stuck at work it was like someone played a joke and crossed the plug wires, thing wouldn't idle Falling on its face, so call AAA

About 45 minutes later she tries to start it and it stumbled she reved it to 1500 for 45 seconds and bang! It was fine, been good for 2 days

Now as we speak I get a phone call, check engine light is back on and she had it scanned same code, misfire cylinder 1

Now I am guessing it's either the cam sensor or crank sensor, but what I learned in back searches is ( I'm guessing) if u replace these sensors u need the computer reflashed?

Is this true? What would u replace first and is there any walk threws on changing the cam sensor and or crank? I read the cam sensor is under the distributor disc? Anyone have any pics?

And again any help is greatly appreciated, thank you!

Danny & Amanda

Quote:

Originally Posted by lightningdan

Thanks for the response, I am leaving my house as we speak to go to the shop, I am installing a new crank sensor, and checking number 1 to see if it's gapped correctly, I read .35 sould be good

Everything seems fine, it even runs and drives fine?! When it threw the light it didn't even hiccup it just came on, a friend of mine also said he would change the injector

I'll post back tonight with the gap of the plug that's in the now, I didn't gap them the auto parts guy said they should be good, I know I should have check that's very poor on my hand... But I seriously doubt that's it, but u never know

Where can I get injectors? Or should I say where can I get 1 stock injector? How much do they run at the dealership?

Thanks for the advice, I was getting afraid people were forgetting about me :)

Please don't mind my spelling my iPad is auto correcting everything.... Errrrr

Just wondering if you've had any luck? Couple things.. The gap should be 0.035 (I'm sure you just left a 0 out) and platinum isn't bad, as long as they are double tipped. I like my Champion 7034's, they are the best I've had in my Jeep. I hear good things about the Autolite XP985 iridium, but haven't used them. Hopefully it's something minor, and gets fixed soon. Also, if it's running fine and just the CEL is on, did you try disconnecting the battery overnight? That should reset it, if it comes on again it's real.
Oh, as far as the injectors (doesn't seem like you need one just yet) I needed mine in a hurry for my DD to get to work, so I got mine from Advance Auto for around $50ish. I'd say you could find at least one or two at just about any chain parts store. For a full set I'd look online, there are options/upgrades.

lightningdan 08-18-2012 01:02 PM

Quote:

Originally Posted by HarryJeepGuy (Post 2696314)
Just wondering if you've had any luck? Couple things.. The gap should be 0.035 (I'm sure you just left a 0 out) and platinum isn't bad, as long as they are double tipped. I like my Champion 7034's, they are the best I've had in my Jeep. I hear good things about the Autolite XP985 iridium, but haven't used them. Hopefully it's something minor, and gets fixed soon. Also, if it's running fine and just the CEL is on, did you try disconnecting the battery overnight? That should reset it, if it comes on again it's real.
Oh, as far as the injectors (doesn't seem like you need one just yet) I needed mine in a hurry for my DD to get to work, so I got mine from Advance Auto for around $50ish. I'd say you could find at least one or two at just about any chain parts store. For a full set I'd look online, there are options/upgrades.

Harry thanks for the concern! Little update, I put the jeep on the lift to change the crank sensor with a good friend of mine who's done it to his boss' and his friends wife's jeep, when we removed the sensor the harness was resting on the exhaust and melted threw exposing a small amount of wires!!

I am wondering if that was the problem?

Yesterday she tried to drive it to try house for me to bring it and the first time it didn't fire up first try, second try it did fine, I took it from my house to advance auto and shut it off, went in got the sensor came out fired it up, and the check engine light was off!!! When I parked it it was on..

Anyway, before we changed anything my friend put the big computer on it and scanned it, it's the very expensive computer the dealerships use, not ur 200 dollar hand held, but anyway, he had misfire #1 stored in its memory, but not check engine light, we cleared the code and installed the sensor, I have 75 miles on it now and the light hasn't come back on so I'm keeping my fingers crossed!

If it does happen again I am going to change the plugs out and switch #1 injector with #2 and see if the misfire moves, that should rule out being a Bad injector...

I appreciate the help, I have platinum plugs but the only have 1 finger coming down to the electrode... Maybe I should ditch them for what ur using?

Thanks again I'll keep u guys posted!!

Jerry Bransford 08-18-2012 01:10 PM

Exactly what brand and model # plugs did you install? Bosch platinum plugs sometimes cause problems. And whoever told you platinum plugs aren't good in a TJ engine couldn't be more wrong. The wrong model platinum plugs are bad but the correct model platinum plugs are superb.

lightningdan 08-18-2012 01:11 PM

I'm pretty sure this is the plugs I got

Buy Autolite Single Platinum Spark Plug AP985 at Advance Auto Parts

I'm going to see if advance can order the plugs u recommend

Jerry Bransford 08-18-2012 01:14 PM

The AP985 plug is an excellent plug choice for 1999 and older 4.0L engines and is one of two platinum plugs that are consistently strongly recommended. The other being the Champion 3034 which is also a platinum plug. If you properly gapped the plugs, you can stop worrying about the plugs being the cause, they are not the source of your #1 cylinder misfire.

The XP985 iridium plug is also an excellent choice but I would keep the platinum AP985 (which I ran in my '97 TJ 4.0L engine) which will easily perform well for 100K miles. There will be no performance difference in any of those plugs for the first 100K miles. It would only be after 100K miles where the XP985 will continue performing well for probably close to 200K miles.

Edit: Misfires in late 90's 4.0L engines can also be cause by weak valve springs. My '97 had that problem and at one time had three cylinders misfiring that wasn't helped by replacing the fuel injectors, spark plugs, distributor cap, rotor, etc. What finally fixed it was a new set of valve springs. And you're sure your #1 ignition wire is ok and plugged in properly at both ends?

lightningdan 08-18-2012 01:21 PM

Quote:

Originally Posted by Jerry Bransford (Post 2697717)
The AP985 plug is an excellent plug choice for 1999 and older 4.0L engines and is one of two platinum plugs that are consistently strongly recommended. The other being the Champion 3034 which is also a platinum plug. If you properly gapped the plugs, you can stop worrying about the plugs being the cause, they are not the source of your #1 cylinder misfire.

I'm going to have to go threw the trash can and grab one of the boxes it came in hopefully I am correct, I'm jumping ahead of the game right now because the light is off, if u knew me in real life I'm a paranoid sob... This is my girls daily driver and I don't want her to be stranded

It's great to know u can order the injectorm from advance, we have a commercial account with them and deal allot with them, hopefully u guys don't hear back from me in awhile!! Lol

I just last week got her air conditioning figured out, after putting in 3 fan control switches, and 2 resistors, I then changed the fan motor itself... That worked for a day! Lol come to find out I did some more back searches and found that the plastic plugs melt, I took the center console apart 1 more time to find them melted! Put some new ends on and it works excellent!

This is a great place, and very helpful thank u guys for taking the time and walking me threw this is it greatly appreciated!

Danny & Amanda

lightningdan 08-18-2012 01:25 PM

Quote:

Originally Posted by Jerry Bransford (Post 2697717)

Edit: Misfires in late 90's 4.0L engines can also be cause by weak valve springs. My '97 had that problem and at one time had three cylinders misfiring that wasn't helped by replacing the fuel injectors, spark plugs, distributor cap, rotor, etc. What finally fixed it was a new set of valve springs. And you're sure your #1 ignition wire is ok and plugged in properly at both ends?

errrrr I am afraid of that! I read a fee back searches of that being the people's problem... I don't want to jinx myself but the jeep has 154k on it... I haven't told her it could be a valve spring issue, did u end up changing the valves with the motor still together? That's so scarey lol...I hope to Christ that's not my problem, hers is a 99 by any chance did crystler change springs by then?

Sorry to answer ur question, yes I checked both ends of wire #1 multiple times... Keeping my fingers crossed!

HarryJeepGuy 08-18-2012 01:26 PM

Quote:

Originally Posted by Jerry Bransford
The AP985 plug is an excellent plug choice for 1999 and older 4.0L engines and is one of two platinum plugs that are consistently strongly recommended. The other being the Champion 3034 which is also a platinum plug. If you properly gapped the plugs, you can stop worrying about the plugs being the cause, they are not the source of your #1 cylinder misfire.

The XP985 iridium plug is also an excellent choice but I would keep the platinum AP985 (which I ran in my '97 TJ 4.0L engine) which will easily perform well for 100K miles. There will be no performance difference in any of those plugs for the first 100K miles. It would only be after 100K miles where the XP985 will continue performing well for probably close to 200K miles.

Edit: Misfires in late 90's 4.0L engines can also be cause by weak valve springs. My '97 had that problem and at one time had three cylinders misfiring that wasn't helped by replacing the fuel injectors, spark plugs, distributor cap, rotor, etc. What finally fixed it was a new set of valve springs. And you're sure your #1 ignition wire is ok and plugged in properly at both ends?

You mean Champion 7034, right? Not 3034. And for the OP, double platinum doesn't mean what you're thinking...

lightningdan 08-18-2012 01:37 PM

Guys, roughly how much does it cost to have the valve springs swapped out? And again if there is damage to the valves already it's kinda throwing the money towards the swap away...

I'm feeling sick

Jerry Bransford 08-18-2012 01:39 PM

Quote:

Originally Posted by HarryJeepGuy (Post 2697746)
You mean Champion 7034, right? Not 3034....

No, I meant 3034. The 3034 is a single tipped (platinum on just the center electrode) platinum which is appropriate for distributor equipped TJs like the OP's '99. The 7034 is a double-platinum tipped (platinum on both sides of the gap) that is appropriate for 2000 and newer distributorless engines.

Jerry Bransford 08-18-2012 01:41 PM

Quote:

Originally Posted by lightningdan (Post 2697765)
Guys, roughly how much does it cost to have the valve springs swapped out? And again if there is damage to the valves already it's kinda throwing the money towards the swap away...

I'm feeling sick

I paid roughly $80 for my springs and while I don't recall exactly what I paid a mechanic in his own small one-mechanic shop, it seems like he only charged me $100 labor or so.

HarryJeepGuy 08-18-2012 01:44 PM

Quote:

Originally Posted by Jerry Bransford
No, I meant 3034. The 3034 is a single tipped (platinum on just the center electrode) platinum which is appropriate for distributor equipped TJs like the OP's '99. The 7034 is a double-platinum tipped (platinum on both sides of the gap) that is appropriate for 2000 and newer distributorless engines.

I guess you learn something everyday. Mine's an 01, that's where the 7034 comes in. I know I've always heard the older 4.0's were less picky, but I thought the general rule was to stay away from single platinum in the 4.0.

lightningdan 08-18-2012 01:58 PM

Quote:

Originally Posted by Jerry Bransford (Post 2697770)
I paid roughly $80 for my springs and while I don't recall exactly what I paid a mechanic in his own small one-mechanic shop, it seems like he only charged me $100 labor or so.

100 bucks?! Even if it cost 200 bucks holy hell that's cheap! I was thinking it was going to be a major price, like trading the jeep in, that kind of price! Lol

And you suggest springs from the dealer ship?

Jerry Bransford 08-18-2012 01:59 PM

Yep, get your springs from the dealer. The possibly weak valve springs were from a bad batch made in the late nineties, all current valve springs are fine. :)

lightningdan 08-19-2012 02:48 PM

Just alittle update, 200 miles on her now with the new crank trigger, no CEL yet hoping that was the problem, don't wanna jinx myself! Lol

lightningdan 08-28-2012 07:03 AM

CEL just came on... Going today to get a price on switching valve springs...

You guys think I should replace the injector as well?

rare-renegade 08-28-2012 12:56 PM

Might try swapping #1 & #2 spark plug wires around to see if the misfire follows. I had the same problem even though the plug wires were fairly new looking and turned out to be a bad spark plug wire. Replaced and no problems since.

bohanm 08-28-2012 01:21 PM

I recently had a cylinder #1 misfire code and it wound up being a failed tappet (thing was totally concave with a hole in the center). Cam lobe was not too pretty either. I'm guessing the oil channel that fed it got clogged up and ran metal to metal with no lube. It was drive-able, but definitely a noticeable a rough ride.

When I got the $2,200 estimate to fix, I decided on going with a gearheadengine.com crate replacement for $1,900. Very close to having it back to running. Good luck with the spring replacement...

lightningdan 08-28-2012 03:22 PM

Quote:

Originally Posted by rare-renegade (Post 2733789)
Might try swapping #1 & #2 spark plug wires around to see if the misfire follows. I had the same problem even though the plug wires were fairly new looking and turned out to be a bad spark plug wire. Replaced and no problems since.

We did switch plugs and injectors... :( no luck thanks for the advice though

lightningdan 08-28-2012 03:24 PM

Quote:

Originally Posted by bohanm (Post 2733884)
I recently had a cylinder #1 misfire code and it wound up being a failed tappet (thing was totally concave with a hole in the center). Cam lobe was not too pretty either. I'm guessing the oil channel that fed it got clogged up and ran metal to metal with no lube. It was drive-able, but definitely a noticeable a rough ride.

When I got the $2,200 estimate to fix, I decided on going with a gearheadengine.com crate replacement for $1,900. Very close to having it back to running. Good luck with the spring replacement...

This is my next fear.... I know the pervious owner took good care of it, and bet he's on this forum somewhere, and my girl followed after purchasing it, religious on Maintenence and oil changes, with 154k this is her first issue

I do hear some lifter noise on first start up but 5 minutes and everything gets warm and no more sound...

I'm going to check that site out now, those are factory replacement motors? Drop in and go?

bohanm 09-20-2012 09:36 AM

Sorry for the delayed response, Lightningdan! The gearheadengine is a longblock and comes with new oil pump and gasket set. Oil pump is the only internal item that you will need to put on (left off due to shipping crate). You'll need all the external items from the bad motor to make it go (oil and valve covers, pulleys, pumps, everything outside the core). Comes with three year unlimited mile warranty. They will cover shipping of the new engine to you and the old one back to them when you are done with it (need to complete within 60 days to get your core charge back). Mine has been running awesome since getting it all back together. I'd use them again in a heartbeat. If $1,900 price is too steep, I've heard that Autozone has crate engine replacements for $1,300 with same warranty. However, no first hand experience with them. Good luck!

imowt 07-07-2013 06:28 AM

I have had the check engine on for over a year now and it will not pass inspection. YES it's the dreaded code 43 ( misfire cylinder one ) I basically only drive it to and from work, but I finally got the inspection ticket. BUT IT'S TIME TO FIX IT.. Tired of avoiding cops
In any event after all the posts and parts replaced I know it's the "weak valve(s)" that's causing the check engine light.
My question is .. my mechanic says it'll be about 450 in parts. Is this about right? He says the head has to come off and its a lil time consuming


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