I have a 98 4x4 4 door with 200,000 on it. I have been dealing with a lurching issue for a while now, but it seems to be getting much worse. Under acceleration, when it hits about 2k rpm, it starts to lurch. It feels like the power just quits for a half second and the tach drops a little. Sometimes it can get pretty rough, sorta like a bucking bronco-but those are FORDIt will do this a few times until it is over 2k and then quit until the next shift when it falls back down. at 70 mph, it hovers at 2k and will lurch gently every 10 seconds or so.

I have replaced plugs and wires, thinking that a wire was breaking down and causing it to misfire. Does this sound like a misfire? I dont know how to take the distributor off so I dont know if thats in good shape or not. Are there any transmission issues that sound be causing this? Thanks in advance!

EDIT: plugs were gapped when i installed them, they are double plat Delco's

 

taking the dist cap off is easy, grab a flashlight and look down at the base of it, there is 2 screws on it, undo and lift dist up.

Tune up parts: fuel filter, dist cap, rotor, PCV valve. And if you are feeling adventurous you can service your EGR valve at the same time and pull those plugs out and GAP them properly if you didnt do it before.

You will find a how to on these forums for all of that if you need the help.

 

Yeah, I forgot to mention that it was a 4.3 so the distributor is in a tight spot and has Torx head screws, for which I have no driver. I was going to try to get some opinions of what it might be before I try that. My mechanic is trying his best to find time but I farm and it's spring so we are all wrapped up.

Do the symptoms sound like something ignition related? I'm on a college kid budget so even buying a 33 dollar dist cap hurts. Thanks for the help.

 

BUMP to attract attention. I need some help guys, this seems to be getting worse.

 

I had a Jimmy that had a bad wire and did the same thing. I really noticed going up an incline and feeding it just a little gas. That's when it hit. Mine was a spark plug wire. You have replaced them as I see. Yes it sounds like ignition and I would check the cap first. Yeah it's tough but if you want to fix it, go for it. Don't cost anything to look. Did you gap your plugs? I've posted a wire check for the wire length vs Ohms resistance at least three times. You might want to double check your wires to see if one is defective but I'd bet it;s the cap/rotor. Replace them both. I understand about tight budgets but now ain't the time.

 

UHG, alright thats what i needed to hear. I'll jump on that next week. Thanks for the help

 

Is your service light on? If so does it flash at all when the bucking happens?

 

Whatch the temp. gadge when it's acting up. If it falls to zero and back up just as quick as the surge, it could be the temp sending unit is bad or the plug on the wire harness isn't making contact. comon prob on many GM's and it drives the computer crazy and shuts the motor down when acting up.

 

No light on, and certainly no flashing. Id sh*t my pants if that happened. And the temp gauge stays planted when all this is going on, the only thing that moves is the tach.

 

It sounds to me like a sensor, or a faulty plug contact. If you do get a code it may be what you need. Most parts stores still diagnose trouble codes for free. If you pull the cap and rotor and they show no signs of excess ware, burn marks, or cracks save your coin, clean them and move on to other avenues. I did the whole tune up and still was getting the surge from time to time. I spotted my temp gage acting funny while it surged and had noticed the temp reading wasn't always in the same zone on the gage. This morning I pulled the plug on and off a few time to clean the contact, not saying it was the fix but it had no surge today with a steady temp reading. The surging isn't my only problem but it didn't show itself today.
I don't see any reason to remove the distributor other than if it's the cam sensor, which is located under the cap, is easier to get to off the motor. If you do end up having to remove the distributor read up on how to line the marks up, my crank pulley has three. I just rotated the engine untill one of the marks fell on TDC and the rotor was pointing at the V mark on the side of the distributor housing. Remove the distributor hold down bolt completely. Raise the distributor out slowly paying attention to where rotor is pointing when the drive gear disengages from the cam gear, that is where you start when putting it back in. (Don't move the motor for anything while you've got it out and it should fall right back in place). The hold down allows for no timing adjustment, if the marks are on once you put the hold down bolt in,(considering you did not turn the motor for anything) you shouldn't have any problems. Be patient, pay attention to how it comes out and don't drop anything in the distributor hole but the distributor itself.
Like I said before some parts stores read codes for free but if you can find someone with a scanner that reads the motor while running it might locate the problem. Even if you had to pay to have it diagnosed, it might be cheaper that replacing the wrong component time and again.

I just caught another blog and it brought this to mind. the V I was talking about is a spot on the distributor with a v shaped tab with a 6 embossed into it. It will be on the passengers side of the distributor housing if you look straight down on it, alone the rim where the cap seats.