Question about 1994 Jeep Grand Cherokee

1 Answer

A rough ride.

I have a 1994 Jeep Grand Cherokee. I replaced the spark plugs, wires, distributor cap, and rotor. I don't think the Cap and Rotor have ever been changed before now, by the look. Anyway, I've checked and double checked the firing order, and all of the wires are on their connections firmly. It idles and accelerates smoothly, but backfires and runs rough once it's up to speed. Any suggestions?

Posted by on


1 Answer

  • Level 1:

    An expert who has achieved level 1.


    An expert that hasĀ over 10 points.


    An expert whose answer gotĀ voted for 2 times.

    Problem Solver:

    An expert who has answered 5 questions.

  • Contributor
  • 17 Answers

Check your engine codes. Even though the light may not be on, there still may be a code that has popped up in the OBD. One way you can check yourself is go to your car and with out starting the vehilce, turn the key on and off five times in a row continusly. After the fifth time, the check engine light should flash. Watch and count as it flashes. Its like morse code. It will flash a certain number of times then pause for a split sec and flash again. Then the light will stay off for a few more seconds and if there is another code, it will repeat the flashing sequence mentioned above with the next code. If you have a digital odometer display, sometimes it will digitally display the code along with flashing the engine light.

Two codes most commonly seen everytime you test is 12 which means in the last 50 times the car has started the battery has been disconnected. The other code is 55 which means that all the codes that are active have been displayed and its done.

If any other codes besides these two come up, take your car to Autozone and have them scan the car with their scan tool. Then they will help pinpoint you in the right direction.

Out of curiosity, has the transmission been changed lately?


Posted on May 10, 2010


1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.

Posted on Jan 02, 2017


Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

Having trouble starting my 1995 Jeep Grand Cherokee. Changed out distributor cap, rotor, module and spark ignitor coil and no luck. Checked for spark by taking loose a spark plug wire and using a sc

is the check engine light on. it sounds like a bad sensor crankshaft positioning sensor or camshaft positioning sensor will cause it not to start.

Aug 16, 2014 | Jeep Grand Cherokee Cars & Trucks

2 Answers

Replaced fuel pump & battery will not start

you have a ignition modulor in the distributor and the crank positon sensor. I have a 1997 grand cherokee and I go through a few crank position sensor

Oct 29, 2012 | 1994 Jeep Grand Cherokee

1 Answer

My 1994 Jeep grand cherokee won't start. It tries to start but doesn't. Tried replacing cap and rotor and still will not start. When I checked the spark it was yellow. What does that mean?

Yellow means weak spark should be blue check the coil tower where the coil wire attaches on the coil for corrosion. Also check the spark plugs for wear.

Feb 03, 2012 | 1994 Jeep Grand Cherokee

1 Answer

I have a 2001 Jeep Grand Cherokee (4.0L) engine. It has power but will not crank. The battery is reading enough voltage.

You can put in your gasoline tank injector cleaner which cleans and unclogs the injectors first. If this does not help you then check one of the spark plugs to see if it is getting any spark to the tip of plug but have someone to check one of the plugs for you safely. Then you can also check inside the distributor cap and rotor to see the connections have not turned black which means no connections to each spark plug when the rotor goes around inside the distributor cap and if you see the connections inside the dist. cap that you need to replace them both. If you take the old distributor cap and rotor to make sure you put the new one the same way you took off the old one by using a permanent black or white marker and make a straight line from one of the outlets where one of the spark plug wire comes from to where the alignment will help you put the newer distributor cap. You can also take a photo of the distributor cap but on top view and then when you take if off to also take a photo view of the rotor as well.

Jun 10, 2011 | 2001 Jeep Grand Cherokee

1 Answer

Changed spark plugs, changed ignition coil. still not getting any spark and car wont start

Please change the rotor and cap before you go any further. The rotor tip can be worn which can prevent charge from getting to the plug wire. The contacts inside the cap could also be corroded.

Apr 22, 2011 | 1994 Jeep Grand Cherokee

1 Answer

1996 Jeep Grand Cherokee 4.0 4 wd - changed wires, distributor cap and rotor - now it will not start? Did verify the firing and that all were plugged in correctly.

If the wires are in the correct order, also make sure that you used the correct starting point, otherwise the base timing can be off by as much as 60 degrees. Turn the engine till the crank damper timing mark is pointing to 0 or tdc on the timing scale. If the rotor is pointing towards the engine, turn one more time. #1 is roughly when the rotor is pointing towards the passenger headlamp. Order is in the direction the rotor turns when cranking. If the engine was running with no problems before the change, only other thing could be that you inadvertently unplugged something or the security system armed. Other possibility is that if you did the change due to a running problem, whatever was causing that finally failed.
If when you remove the cap again you find that the rotor is damaged, check the dist shaft for side play.
Are you getting spark?

May 25, 2010 | 1996 Jeep Grand Cherokee

1 Answer

I have a 1994 Jeep Grand Cherokee Laredo 6 Cyl. The vehicle was kind of running rough on idle. Take in consideration that I have replaced the spark plugs, spark plug wires a while ago. So I decided to...


Apr 23, 2010 | 1994 Jeep Grand Cherokee

1 Answer

Poor gas milage

Poor gas mileage can have many roots but the best way is always to start with the ignition system. Have a look at the sparkplugs, if you've got the I6 4.0 engine it is easy to check them. Spark plugs are cheap and easy to replace. Also check the spark plug wires, be sure the connections are tight and free from rust. Check the distributor cap and rotor and if they are rusty/greasy clean them up. After you've cleaned and checked the ignition items (spark plugs, wires, distributor cap and rotor) you can move on to the fuel injection system.
Replace the air filter, it is cheap and most people overlook that single item.

When was the last time you replaced the fuel filter? A clogged fuel filter reduces power drastically which in turn affects fuel mileage.

Jan 27, 2010 | 1994 Jeep Grand Cherokee

1 Answer

1995 jeep grand cherokee with 4.0 engine back fires through air fliter box when driving and the vehicle loses power.

Possibilities can include:

Clogged catalytic converter - needs replacement or removal.

engine timing off - adjust the camshaft position sensor.

distributor cap & rotor - replace along with new spark plugs and wires

Nov 21, 2009 | 1995 Jeep Grand Cherokee

Not finding what you are looking for?
1994 Jeep Grand Cherokee Logo

288 people viewed this question

Ask a Question

Usually answered in minutes!

Top Jeep Experts


Level 3 Expert

75842 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22156 Answers

Kevin Daniels

Level 3 Expert

1455 Answers

Are you a Jeep Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides