Hi. I have a 99 Ranger and I've been haivng some engine trouble lately. Basically like the topic says, my engine is shaking when idle (enough to slightly move my whole truck). And when I'm driving its almost like i'm fighting my limiter. The truck will be driving and start to go kinda...slow for a second then spurt foward again I guess? Kinda like when the limiter kicks in for a second.

Either way it seems to be getting worse over the days.

Thanks for any help I can get..

 

Welcome to FTE.

We need some more clues, to make a better guess.
Which engine & how many miles on your ride & where are you on due & past & present scheduled maintenance items, like filter changes, spark plugs & wires.
Have you made any mods to this ride?????

Do you have a CEL on???? If so have your favorite autoparts store do a no cost computer trouble code scan, then post ALL the codes found & the order in which they were retrieved, as they can offer up clues that help diagnose problems.

If you don't have any codes, then do a fuel pressure & flow test & lets see what they show. Could be a weak fuel pump, or maybe a clogged fuel filter, if it hasn't been changed lately.

If it isn't fuel delivery related, then maybe it's spark related, so check the condition of your plugs & wires & do a spark check with a inductive timing light on each wire, to see if you can catch one acting out.

If that checks out ok, have a look at the MAF sensor & see if it might be dirty & confusing the Computer with corrupt data.
If it's dirty, then look up stream to find out why!!!!

If that seems ok, then look for a vacuum leak. Check all your vacuum lines, including the PCV valve, vapor recovery system & intake manafold gaskets.

Just some things to ponder in getting started on your troubleshoot.
Let us know what you find.

 

Thanks for the detailed response! Though hoenstly I don't know what you mean by CEL and such. Unfortuantly, I'm not really a car kinda person; know very little about them unfortuantly. However situations forces me to try a DIY approch so...

I've had my truck for almost 6 years now, and have 96k miles on it. It's a 2WD v6 engine, 3.0L if i recall correctly. Looking through all my papaerwork I honestly couldn't tell you where I am on scheduled maintence. Probabaly behind. I did have a tune up, however it was several years ago and the actual paperwork seems to have eluded me for the time being. On filters, I know my oil filter is fine. My fuel filter however is a different story and I believe I have heard that it needs to be replaced or cleaned. On spark plugs and wires, I'm not sure if they have possibly ever been changed. ;x

There are no mods also on it so nothing crazy going on. Just a guy that doesn't take the best care of his car. I'd check the spark plugs and such for you, but I don't know even where they are on my truck. However this seems to be a progressively worse problem as it seems to be escalating as the days have gone by. And elt's not even talk about the shaking and spurting when I turn on the AC. ;x

I can go to autozone to see if they can check codes for me; I'm just not really a fan of driving at this point without figuring out what possibly is the problem, as I'm afraid of driving it and only making it worse. ;x

 

Might want to check your motor mounts also.

 

Where are the motor mounts and how do I check them? :[ And I was mistaken my truck is a 4.0L not a 3.0, sorry.

I did check my air filter though and i could for sure use a new one of them. However for sure knowing my plugs and wires haven't been changed I am thinking of checking/changing them however I don't have any idea where they are.

Sorry for so much trouble, I have very little clue as to what I'm doing here.

 

OK, good honest feedback.

CEL = Check Engine Light. it's in the instrument panel & it'll come on & stay on, if the computer detects a sensor problem it's monitoring, with the emissions systems.

It is possible to have "pending trouble codes" stored in the computer, that havent happened often enough (matured), to turn the CEL on, but a computer trouble code scan at AZ will call it/them up. So post ALL the code numbers found.

With the mileage you have on your ride & not really knowing where you are on scheduled maintenance, it could be a number of things.

So maybe begin with the computer trouble code scan & lets see what turns up there.

Then consider continuing on, with the less expensive scheduled maintenance things, like Air & Fuel filter changes & see what happens.

Your owners manual will show you how to change the air filter, or maybe the guys at AZ will show you how, maybe even do it for you, as it doesn't require any hand tools.

Changing the fuel filter is a little more involved & requires getting under the truck on the drivers side, about where your feet hit the ground when you get out.

The fuel filter is mounted underneath, on the chassis frame rail & is under pressure, that must be bled off, before removing the lines, so you may want to have this done at a garage.

This may be your power problem, the filter can clog up & the fuel pump just can't push enough fuel through it (flow rate) to meet demand.

With this mileage, you may also have other problems, like worn spark plugs with too wide a gap, such that the weak spark blows out when you put the engine under load.

The change intervial for plugs & wires is 100K & your right at it.

I found my 99's spark plug gap to be way over spec at only 50K miles, so if you've never had yours looked at in 96K, I'd bet they need service.

And if the air filter hasn't been changed in all this time, it's WAY over due too. both it & the fuel filter are scheduled for change at 30K mile intervials. So a cloged up air filter, sure can mess with the engine power also.

I just finished doing my Rangers 60K mile fluid & filter changes this week. New Motorcraft Air & Fuel filters!!!! So if pawpaw, can learn to do it, I'll bet you can too.

On the spark plugs & wires, raise the hood tonight & with the engine running, look on top & both sides of the engine & see if you can see any sparks coming from the ignition wires. If their leaking any high voltage, you'll see, maybe also hear the "snap", of high voltage arcs. Let us know what you see & hear.

If you don't want to learn how to turn wrenches on your ride, then take it to the Dealer, or a trusted shop, to get the due past & present scheduled maintenance done.
This would include fluid & filter changes, other than just the oil & filter changes you've had done.
Expect to have to lay out about $300-$400 to have it brought up to date, if others do it, or about $100 if you do it all.

On Edit: I see you posted again while I was replying.
So you have a 4.0L engine, not the 3.0L.
So we need to maybe add intake manafold vacuum leaks to the suspect list.
Sounds like you may be of a mind to learn how to begin turning your own wrenches, so maybe begin by looking at some repair manuals in your library & see who's format suits your skills, before investing in one.
If you want lots of detail, maybe consider a repair CD.

Let us know what you do & what you find.

 

I dont have a CEL on., However I have gone to AZ and the error code shows I have a misfire in the 4th cylinadir. My friend is over now and helped me locate the spark plugs. When we pulled the plug the center conencter isn't in there (looks to be broken off) and we don't know where it is. I don't know how big a gap is beyond reson, but its about the width of two of my knifes blades apart.

We haven't checked the fuel filter because of how bad the 4th spark plug looks. However he doesn't know if that would be the cause of the shaking and such or not. What would you suggest from here? (He owns an rx-7 so his experience with non-rotary cars is limited)

 

I can't figure out how to edit my post here so I'll just do a new reply. Sorry ;x

We changed the 4th sparkplug but the engine continues doing the sputtering thing. Right now we're kinda stuck on what to do. We can't get to the other ones easily right now so not sure if they're the problem too or if we need to go onto chekcing the fuel filter or something. Friend says he doesn't know how to depressurize the fuel filter on the truck, though we did locate it.

That's the situation currently though.

 

Well to depressurize the fuel system, first disable the fuel pump.

This can easily be done several ways, like thumping the in cabin fuel pump cut-off inertia switch, to cause it to trip, or disconnecting it's electrical power connector,( it's located in cabin, on the passenger side firewall, just above the carpet), pulling the fuel pump power relay, located under hood, in the power distribution box, drivers side inner fender, up close to the brake master cylinder, or pull the fuel pump power relays fuse.

Once the fuel pump is depowered, crank the engine 10-15 seconds, until it ceases trying to start, this will bleed fuel pressure off.
At this point, if it's warm outside, I also open the fuel cap, to bleed off any tank built up air pressure. I leave the cap loose, until the filter is changed.

You'll need a disconnect tool to get the fuel line loose. I like the "Dorman 800-009 one piece molded plastic quick disconnect tool.
It looks kinda like a grey top hat, with the crown cut out & a slit down the side & through the brim, so it can be spread open & slipped over the fuel line.
The tall part slips into the line connector, to spread the out of sight circular spring, to cause it to turn the connection loose, so the filters line will slide out.
Sometimes it's a real bear to get them apart.
Some folks say they have better luck with the scissor type release tool, but I had two of those hummers & the part that slips into the connection, to release the spring, wasn't long enough to get the job done.
The plastic Dorman tools flange was half again as long & the lines parted with very little effort.

Anyway seeing as how this one likely hasn't been changed in 96K, or 8 years, be prepaired to use some of your best words of persuasion!!!!! lol

Good idea to change the #4 plug imo.

You need to use double platinum replacement plugs, for our "waste spark ignition system.

Preferably Motorcraft, or Autolite, who makes Motorcraft to Fords specifications.

These engines are kinda persnickety about the spark plugs they get.

Motorcraft AGSF-22PP is the specified replacement plug for the 99 4.0L engine.
They should be gapped at 0.052"-0.056".
I'd suggest setting them to the .052 spc, as the gap is always openng up as the plug is used. It'll also make for a hotter spark & easier winter starting in real cold weather.

They should be tightened to a torque of 7-15 foot lbs. I'd also suggest using a dab of high temp, nickle loaded, antisieze compound on the spark plug threads & tighten the plugs to the low side of the torque spec, to allow for the lubricity of the antisieze compound, so you don't over tighten them.

YUP, if the other plugs are way out of spec on gap, or in theshape of #4, it sure won't make the engine run better.

Without more diagnostic tests to yield more clues, we're just speculating on what best, to work on next.

If you suspect the air & fuel filters have never been changed, I'd do them, because they're WAY past due & could be contributing to your driveability problems.

The specified fuel filter is Motorcraft FG-986B, Airfilter FA-1658, PCV Valve EV-225.

I'd pull & inspect all the plugs. If #4 was in as bad a shape as you've posted, the others aren't likely to be any better & yes they certainly belong on your driveability suspect list.

We have about 1 hour to edit a post, then the edit button at the bottom of the post window goes away.

Keep us posted on how things are going.

You & your friend can likely fix this problem, but without some diagnostics, you might have to sneak up on the problem/s, by replacing the next most likely suspect part, but most of the suspect parts we're talking about are normal maintenance things, that are due for replacement anyway, so this is just like performing/catching up on, normal maintenance, rather than throwing parts at a problem, trying to fix it.

 

You're very helpful to someone who know into the negative about cars. ;x

However in the above quote I'm not really sure how I would begin to do any of that.

We didn't use the double platinum ones though. Think we used about the cheapest one we could; some Champion ones I believe. Got a 6 pack to replace them all, but since we didn't have a ratchet extention or anything so we could only replace #4 at the time.

I am planning however to take your advice and go watch the spark plugs and such tonigth once it gets dark. However, as I live in central Texas cold mornings have enver really been an issue for me haha.

I suppose I'll keep posting as I go along. Sorry for being so clueless and posting so much. The help truely is appreciated though. Your detailed intructions though make it 100x easier on me not only to locate stuff but also trying to fix it as well.

 

No problem on the learning thing, I was there at one time too.

After paying the VW Dealer $50 bucks back in 65, when that was a bite out of my pocket, to do my 3K mile mainenance & half way home, havig the engine sputtering & bucking & about to completely lay down on me, I began to have doubts about having others turning wrenches on my ride.
Anyway, after getting it home & doing some inspections, I found the Tech had forgotten to torque the danged spark plugs & all were loose & one was about to fall out!!!!.

So out came my spark plug socket & wratchet & back in went the plugs.
My next stop was Sears, to buy a Torque Wrench, so I could properly tighten up those 65 VW Beetles spark plugs.

Just finished using that same torque wrench on the Rangers brake caliper mounting bolts this week.

If your going to begin turning your own wrenches, like I did, at least invest in a repair manual, or CD. It'll pay for itself in short time & make your repairs go faster & be less worysome & frustrating.

like I suggested above, check out your local library & see who's repair manuals format & detail suit you best.
I happen to prefer Haynes or Clymer, but thats just me.
The more much more expensive Factory Repair Manuals by Helm Inc, are good, as are the online CD repair manuals, I'm told.
So you have several choices to choose from.
On Edit: WOOPS forgot to answer your question about the spark plug numbers.

The .052 number (fifty two thousandths) of an inch gap, is the distance between the spark plugs threaded end, inside center electrode & "L" shaped ground electrode, that extends from the threaded end of the plug, over the center electrode.

This distance is the "Spark Gap" & is to be checked, or set if necessary, with a wire feeler gauge, so the spark gap is in specification as required by Ford.

The gap will goveren how hot the spark is & how well it'll ignite the air/fuel mixture & thus how much power & fuel economy you'll get.

The double platinum plugs I listed above, are of the proper heat range, so the plug doesn't operate too cold or too hot & remains clean so it'll do it's thing better, over a longer time.

Because our coilpack "Waste Spark" system, fires/sparks a spark plug TWICE as often, as the old single coil distributor spark system, the spark plugs get worked TWICE as often & TWICE as hard, so the spark plugs & wires need to be up to Fords specifications, to work real good & last a long time.

So if you used a standard, non double platinum plug, of the wrong heat range, it may not run as well & it's spark electrodes will wear out & the spark gap will open up really fast, maybe in as little as 12K-15K miles, so keep a check on them, if you use them.

Also keep a close ear for spark knock (ping) on a pull, or when accelerating. If you hear ping, get the proper plugs installed without delay, as you could seriously damage your engine, if you ignore the ping.

The tightening/torque numbers I listed in, inch/pounds, is to ensure the plugs aren't over tightened & damage their, or the engines threads & to ensure their tight enough to properly conduct heat to the head, so they operate at the proper heat range.
The antisieze compound on the plug threads, will ensure you being able to get them out for replacement, or service without problems later.

 

Well as it is dark I went out there and looked around the engine in darkness (and man is it ever dark out there) but I don't seeing any arcing nor snaping sounds, so it doesn't look like anything is leaking out that way.

Work on it more tomorrow and hopefully have more updates. I'll look into those double platinum sparkplugs though. Consider the poor care I keep my vechile in, they would probabaly be a more solid investment. I assume the doube plat ones you speak of are the P2 ones like #4 we pulled out earlier? The one we have right now are copper or something.

Can I really overtighten them though? It took us 30 minutes jsut to get #4 out because it refused to move at all. Some of that may have jsut been our lack of an extention though and the given space.

I would assume I would simply tighten them until they were securely in there, much like you do with any threaded object. Is that the wrong approch to have?

 

Ok good feedback, so it seems as though you might not have external flash over problems, or the plug wires breaking down & arcing to the engine block.

Sounds like you bought the standard copper core spark plugs.
I agree with the double platinum plugs likely being the better investment, as your lax on maintenance.

If you still have the OEM factory plugs in the engine now, the passenger side bank, cylinders 1-2-3, will have a Motorcraft AGSF-22PG.

The drivers side plugs, cylinders
4-5-6, will have Motorcraft AGSF-22P.

The PG suffix denotes the plugs in this bank of cylinders, because the spark in our system has reverse polarity for this bank of plugs & emits from the ground electrode, to the center electrode, will have platinum on the ground electrode, (PG) to reduce wear & save the Factory some money, by not having platinum on both electrodes.
So these plugs are to be used only on cylinders 1-2-3.

The "P" suffix, denotes that the center electrode has the platinum, because the spark polarity on cylinders 4-5-6, causes it to emit from the center electrode to the ground electrode, so the center one needs to be platinum, to reduce wear & cut Factory costs.
These single platinum plugs are to only be used in cylinders 4-5-6.
Problem is, we can't get replacement single platinum plugs, with the platinum only on the ground electrode, (PG) for cylinders 1-2-3.

So the factory specifies double platinum plugs, that way it won't matter which bank of cylinders they're used in, but they'll cost us a little more.

I suppose if money were really tight, you could opt for the available center electrode, single platinum plugs AGSF-22P, for cylinders 4-5-6 & double platinum AGSF-22PP, for cylinders 1-2-3, so their ground electrode has the needed platinum!!!! lol But I doubt you can buy them in singles, or packs of three!!!!?????

On the tightening thing, what you describe sounds about right.

I don't know how big & strong you, or your friend are, but whats normal tightening torque for me, at 5'7" & 145 pounds, might be different for a 6'6" 250 pounder!!!! lol.

If you or your friend doen't have a torque wrench, tighten the plugs until they bottom out, then snug them down by hand a little more, say using a 3/8 drive 6" long wratchet, without a cheeter bar, piece of pipe on it & you'll likely be about right.
Just don't get crazy on us & wrench them down with a 18" long 3/4 drive breaker bar!!!!! lol

 

Well my CEL came on maybe an hour ago while driving, however it's very hot outside so I'm not sure if thats a reason or not. I havent been able to change the other spark plugs yet however I'm going to attempt to do so later today.

Does the CEL mean the problem is getting worse? ;x

 

The CEL coming on is the computers way of indicating it has detected an out of parameter condition with one of it's sensors.

Could be any number of things, maybe another misfire code, if it's still missing badly.

So get the computer rescanned & post the ALL trouble code numbers found.

Probably a good idea to get the plugs changed out. I'd also get the fuel & air filters done too.

If you don't have the tools to do the plug change, ask AZ if they have a Loan-A-Tool program. Most do for a refundable deposit.

Also if your not going to invest in a repair manual, or CD, go to the AZ web site & enter your vehicles particulars, they have a repair section with fairly good "how to" instructions & illustratons, on many of the things you want to do.