Ignition problem after tune up

KRYSTIN.GIESKE1

MEMBER
1994 FORD EXPLORER
4.0L
6 CYL
4WD
AUTOMATIC
100,000 MILES

I have the vehicle listed above xlt model. We just replaced the spark plugs and wires one at a time so they were put back right, and also replaced the coil pack. Now during acceleration it sounds like we are driving over one of those wake up strips and gets worse at 45 mph. We can't seem to find anything wrong. They were pre gaped plugs and we double checked them anyways. Any ideas as to what might be the problem?

1 Reply

JACOBANDNICKOLAS

MECHANIC
109,885 POSTS

Hi,

First, reconfirm they were put on correctly. I will tell you the wire routing is extremely important on these vehicles simply if it done wrong, they melt on the exhaust system and short. Plus, (and this is from memory) they plug wires are somewhat difficult to get on the plugs on a few of the cylinders. Make sure they are fully seated. You should feel a click when installing them on the plug.

Do me a favor. Just to confirm, I've attached two pics. The first shows the firing order. The second shows wire routing. Confirm these things are correct.

Next, in the dark, start the vehicle and open the hood. Check to see if there is any arcing coming from the plug wires at any point.

Last, if there is nothing obvious, we need to retrieve diagnostic trouble codes. This has an OBD 1 system and doesn't require a scan tool. By doing this, it should indicate specific cylinder misfire locations and then we can remove the spark plugs and check them as well as the wires. Here is a link that shows how it's done:

https://www.2carpros.com/articles/ford-lincoln-mercury-obd1-1995-and-earlier-diagnostic-trouble-code-definition-and-retrieval

Let me know what you find.

Joe

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