Engine misfiring bad?

Could be plug, wire or fuel injector. Is the miss constant or intermittent?

This guide can help us fix it

https://www.2carpros.com/articles/engine-misfires-or-runs-rough

Please run down this guide and report back.

I have done a tune up from the rotar to the plugs. I have a miss in #4 and #5. I also have white steam coming from the exhaust. With a smell i cant describe. But the tricky part is im not losing any coolant. I have been chasing this problem for weeks and i am stumped. Please help. Also there is enough condensation from the exhaust it will run down the drive way.

Before goiing through too much trouble,double check your spark plug wires to be sure they are on the proper terminal on the distributor cap. I have attached a picture of the diagram for the spark plugs. (not sure which engine you have--let me know if your engine isn't on the diagram)

If the spark plugs wires are correct then it sounds like a blown head gasket. Have a compression check done on those two cylinder (all cylinders actually). You can sometimes rent a compression gauge from a local auto part store. (they will fully refund you money when you return the tool).

If possible, have a shop to do a cylinder leakage test on those cylinders if the compression test shows low compression. this test forces compressed air into the cylinder. In your case if the air comes out of the ajacent cylinder, it would indicate a blown head gasket, warped or cracked head.

My caravan has a slight miss when sitting at a idle and when on the highway. i changed out the plugs, wires, coil, fuel filter, pcv, airfilter and it keeps kicking on the service engine soon light so i hooked up my obd2 reader and it says that cylinder one is missfiring still my local mech shop told me to take it into dodge but i figured id ask you guys before i go spend hundreds at dodge for something that might be small that i missed? The battery was getting weak so i put a new one in and thats when the miss started but i couldnt see that making a difference but maybe?

my obd2 reader and it says that cylinder one is missfiring : equates to P0301

Check the spark plug, fuel injector and compression for cyl no. 1

Misfires can be caused by worn or fouled spark plugs, a weak spark (weak coil, bad spark plug wire), loss of compression, vacuum leaks, anything that causes an unusually lean fuel mixture (lean misfire), an EGR valve that is stuck open, dirty fuel injectors, low fuel pressure, or even bad fuel.

sounds like #1 wire is bad but do the following test

Engine Mechanical problem
1999 Dodge Caravan 4 cyl Two Wheel Drive Automatic

miss firing on 4th cylinder changed wires and plugs
put new coil box what else could the problem be could it be somrthing serious?

Hi there,

best check compression next, also injection pulse and injector, also check for a vacuum leak around the manifold near that cylinder, start here.

mark (mhpautos)

My 98 Dodge Grand Caravan has been acting up, missing and back firing. I took it in and had it put on a computer, the results came back misfire on #3 cylinder. So I changed all the spark plugs and plug wires. The problem was not fixed. My brother in law said that the same thing happened to his parents van and it was something in the computer sending the wrong signals to the engine. Any ideas?

More likely a bad injector. First do compression test to be sure it is ok. Then, since the plugs are new, remove #3 and any other and compare the color. Does that engine have just one coil?

To be honest I am not sure how many coils there are. The engine is a 3.8L if that is any help. The #3 spark plug is the back middle one and they are impossible to get to without having to remove part of the engine so taking it out is not really an option.

If you arent willing to remove the plug and check it, then im not sure how much help I can be to you.You wouldnt believe some of the things that have to be done to get access to areas, but it helps make a more accurate diagnosis.

I guess if that is the only way, I will look into having it done. The thing is I just paid someone (a professional) to put the spark plugs in a week ago. I had to problem before and after the plugs and wires were replaced. And it has only been a week since I did that.

Engine Performance problem
1998 Dodge Caravan 6 cyl Front Wheel Drive Automatic

Keep getting random cylinder misfire codes.It is burning some oil.Since the bottom end was done.I beleive I need valve seals done.If these were real bad.Would it cause the misfire codes? Or should I look else where?

When was the last tune up?

Your main power wire has a bad connection on the dash cluster, you can google the repair. Fixed mine in a afternoon.

Tuned up 6 months ago.I do beleive I might have my answer.It also has a high pitch sqeal.I now suspect the belt tensioner.Could it be that easy?

If I may add a few tidbits of information, forget the injectors. Chrysler buys their injectors from Bosch in flow-matched sets, and has extremely little trouble with them. Since 1990, I've read about one bad one. If you were to suspect a bad injector or spark plug, swap that one with one from a different cylinder. Erase the fault code, then see if a code sets for the cylinder you moved the suspect part to.

When you have a running problem, you need to list the engine size right away. There can be four or five, and some of them have wildly different ignition systems from the others. You also need to list the mileage and transmission type. We make generalizations based on that when deciding the order of things to check. It's not fair to make us guess, or to waste time dragging that top secret information out.

You're right that number 3 is the rear, center cylinder. It is easy to get to from underneath when the van is on a hoist. If you try to do it from the top, the long black bucket holding the wiper system can be removed to improve access.

The 3.8L uses three ignition coils in a coil pack, or assembly. The easiest is to get a good used one from a salvage yard to try as a test. While it's not real common, a partially-shorted coil can fail to develop sufficient voltage to fire the pair of spark plugs under all conditions. What you hear as a backfire could be the unburned fuel from a misfire going into the exhaust system where it fires and creates the sound of a backfire.

A deteriorated spark plug wire can cause the same symptom as a weak coil. A better suspect is a failing crankshaft position sensor or one that was installed improperly without the spacer needed to set its critical air gap. If the history of that sensor is unknown, your mechanic can use a scanner with graphing capabilities to record the sensor's signal while the problem occurs. If you see the signal pulses drop out completely, intermittently, suspect the sensor is failing. If you see the signal voltage drop just a little, but it's enough for the computer to be unable to read it, resulting in a momentary misfire, suspect the air gap is too big.

You don't have to run to your mechanic to have diagnostic fault codes read. Chrysler makes doing that yourself much easier than any other manufacturer. Cycle the ignition switch from "off" to "run" three times within five seconds, without cranking the engine, leave it in "run", then watch the code numbers appear in the odometer display. You may only get a code indicating which cylinder is misfiring, but if you're lucky, one will set related to the crankshaft position sensor. Remember that fault codes never say to replace a part or that one is bad. They only indicate the circuit or system that needs further diagnosis, or the unacceptable operating condition. When a part is referenced in a fault code, it is actually the cause of that code about half of the time. First we rule out wiring and connector terminal problems, and mechanical problems associated with that system.

Also be aware a lot of people, including some mechanics, still believe there is no fault code to be read if the Check Engine light isn't on. That is absolutely not true. There can be over 2,000 potential problems detected. About half of them refer to something that could adversely affect emissions. Those are the codes that turn on the Check Engine light. A fault code related to a crankshaft position sensor or camshaft position sensor will usually not turn on the Check Engine light. That is because with a totally-failed sensor, the engine won't run, and a non-running engine can't create excessive emissions.

No, a tensioner won't cause that. As far as the oil burning, when valve seals are bad, usually you will get blue smoke when you first start it and wide open. Is that what is happening?

As far as the noise, the tensionier could cause it. Remove the belt and start the car to see if the sound is gone. Only let it run a few seconds, just long enough to see if the sound is gone.

Let me know what you find.
Joe

Hi Joe:
Turned out dis. cap was cracked.Tensioner bearing was shot. Thanks for the advice. Rusty
P.S. As to the last question,yes its blue smoke on start-up only.Thanks,again

1998 Dodge Caravan 6 cyl

when i start it up in the morning it will misfire a little bit. as the engine warms up it gets worse. it cuts out real bad when you try to take off but once you get going it does better. it throws a random multiple misfire code. i have changed the fuel pump, plugs, wires, cap and rotor. when i changed the plugs it ran fine for a while but it went right back to cutting out. im not sure what to check now

good job! Glad you found the problem. Was the cap replaced when you tuned it up?

As far as the blue smoke at start up, my first guess is valve seals.

is there a check engine light on?

Hey Joe: The cap was new,but cheapest.The other problem was the #4 wire to cap.I did not install all the way.It then started to short,hence the crack.I should of paid more attention to what the cpu. was telling me in the first place,(#4 misfire) Just may attempt valve seals.The front cylinder head anyway.The rear looks like a nightmare,any advice?I'm hoping a small Porter cable pancake compressor will work,as long as theres no leakage,right?Thanks,Rusty

yes the engine light is on. when i hook it up to a computer it says random multiple misfire.

It should work. Just work carefully and quickly. I've seen valve spring compressors (for when you do the work with the head still on) open the valve's seal, compression is lost, and the valve drops in. Also, the retainers are a little tough to deal with because of size and they like to shoot off if not properly seated, so keep your eyes on them.

As far as the back, yes they are a pain. However, when you remove the plenum, believe it of not, there is room to work. The worst part is hooking up the compressor to each cylender. Believe me when I say, I would love to meet the engineer that comes up with some of the ideas. My guess is it's the CEO's nephew that got an engineering degree online for around 50 bucks. Life could be so much easier for everyone if things were just thought through.

Let me know if you have questions or problems, and good luck.

Joe

Maybe I'll get lucky.The bad one(s) are at the front.Shouldn't I be OK even losing compression,as long as that cylinder is TDC? Yes,I know what you mean about engineers.I just replaced the Steering rack when I could of got away with replacing the one 1/4 line.Nobody knows where to get fittings or duplicate the fancy flat flares?Maybe I should of asked Toyota?Since thats who made it?I'm sure they would only be happy to sell me a new rack.Picked up one from wreckers for 80 bucks off a 2000.

My code says that I have a cylinder misfire detect (code P0300- P0305

Hi there,

I would start with a tune up as this may just be a faulty plug or lead setting off this code, start here.

Mark (mhpautos)

If it is only the front, you should be fine. If you run into trouble, let me know. And yes to having the pistons at TDC.

I guess I should elaborate more on the van.

When it rains, the van stalls, it revs up and down by itself. It will do this for about 10 minutes, then it's fine until the next time it rains. I would have the van parked over night, and if it rains during the night, this is what happens.

I had a tune up and I changed the spark plugs, wires, dis.cap and rotor.

I still have the same problem.

Joe:The rack I picked up had o-rings on the main lines on the flares into the rack,which the wrecker cut,to put on a socket,off a 2000 caravan.My 98 never had these 0-rings.Do I need to buy a couple to put on? Or will they be fine without?I hate to reassemble & have leaks,there.Fittings are a pain to get at.These are the bigger lines from pump,Thanks.
Rusty

That is a good question. When you change years, everything changes. If they will go on for you, I would recommend replacing the O-rings. And I agree, there is no room.

Joe:Just wanted to update/correct.For the loyal followers.So they don't make a mistake.Those lines into the rack,from the pump did have O-rings.It was hard to tell,they were very thin/worn.For what they are worth.Its better to replace.The only thing I must of done incorrect was turning the coupler to mate with pinch bolt on the steering?Now steering wheel is 1/4 turn counter clockwise?With wheels straight?Don't get it?The roll pin only installs one way?Just as the pinch bolt?Should I have unlocked the steering wheel first?Or maybe off on the Tie rods(s) install? Rusty

Actually, the steering alignment is adjusted through the tie rods. When it is aligned, make sure the have the steering wheel straight when they adjust the alignment. When you put the tie rods back on, my guess is that is what happened.

my shows trouble codes 300,306,303,1294 i changed the plugs cap rotor wires,ran two bottles injector cleaner through two tanks off gas and engine light still shows codes ,van runs good,just at idle you can feel a little vibration in sterring wheel,i need a inspection,also replaced water pump and timing belt.will you help me thanks raymond

[quote:a4768a9840="bubbabe"]Engine problem
1998 Dodge Caravan 6 cyl Two Wheel Drive Automatic 105000 miles
----------------------------------------------------------------
my shows trouble codes 300,306,303,1294 i changed the plugs cap rotor wires,ran two bottles injector cleaner through two tanks off gas and engine light still shows codes ,van runs good,just at idle you can feel a little vibration in sterring wheel,i need a inspection,also replaced water pump and timing belt.will you help me thanks raymond[/quote:a4768a9840]


you need to clear code s
and drive it for about 30 to 50 miles
if no light return
try for a sticker
if you have check engine light return post the code
let me know
good luck

[quote:1f90fb6b1e="BMRFIXIT"][quote:1f90fb6b1e="bubbabe"]Engine problem
1998 Dodge Caravan 6 cyl Two Wheel Drive Automatic 105000 miles
----------------------------------------------------------------
my shows trouble codes 300,306,303,1294 i changed the plugs cap rotor wires,ran two bottles injector cleaner through two tanks off gas and engine light still shows codes ,van runs good,just at idle you can feel a little vibration in sterring wheel,i need a inspection,also replaced water pump and timing belt.will you help me thanks raymond[/quote:1f90fb6b1e]


you need to clear code s
and drive it for about 30 to 50 miles
if no light return
try for a sticker
if you have check engine light return post the code
let me know
good luck[/quote:1f90fb6b1e]
i have done this twice already and codes pop back .after about 40 miles,any other suggwestions thanks

[quote:48a010de57="bubbabe"][quote:48a010de57="BMRFIXIT"][quote:48a010de57="bubbabe"]Engine problem
1998 Dodge Caravan 6 cyl Two Wheel Drive Automatic 105000 miles
----------------------------------------------------------------
my shows trouble codes 300,306,303,1294 i changed the plugs cap rotor wires,ran two bottles injector cleaner through two tanks off gas and engine light still shows codes ,van runs good,just at idle you can feel a little vibration in sterring wheel,i need a inspection,also replaced water pump and timing belt.will you help me thanks raymond[/quote:48a010de57]


you need to clear code s
and drive it for about 30 to 50 miles
if no light return
try for a sticker
if you have check engine light return post the code
let me know
good luck[/quote:48a010de57]
i have done this twice already and codes pop back .after about 40 miles,any other suggwestions thanks[/quote:48a010de57]


IS IT the same codes ?
check fuel injectors
check for a vacuum leak
rpm not correct

[quote:858b3de73c="BMRFIXIT"][quote:858b3de73c="bubbabe"][quote:858b3de73c="BMRFIXIT"][quote:858b3de73c="bubbabe"]Engine problem
1998 Dodge Caravan 6 cyl Two Wheel Drive Automatic 105000 miles
----------------------------------------------------------------
my shows trouble codes 300,306,303,1294 i changed the plugs cap rotor wires,ran two bottles injector cleaner through two tanks off gas and engine light still shows codes ,van runs good,just at idle you can feel a little vibration in sterring wheel,i need a inspection,also replaced water pump and timing belt.will you help me thanks raymond[/quote:858b3de73c]
yes same codes but i will check for vacumn leak and injectors somehow,i know to spray starter fluid around suspect areas and if motor changes rpms,then theres a leak,but how do you ckeck the injectors,thanks

you need to clear code s
and drive it for about 30 to 50 miles
if no light return
try for a sticker
if you have check engine light return post the code
let me know
good luck[/quote:858b3de73c]
i have done this twice already and codes pop back .after about 40 miles,any other suggwestions thanks[/quote:858b3de73c]


IS IT the same codes ?
check fuel injectors
check for a vacuum leak
rpm not correct[/quote:858b3de73c]