My very own hesitation/bucking thread

[pierceME311]

Has Ford ever had a bulliten on this problem? It's so common I would think that they would know about it, I searched for it but I only found threads about people asking or posting how to fix it. I'm going to start searching the web for a Ford company fix for it, if one exists. Maybe they just ignore it and pretend like it doesn't happen. I still haven't cure my bucking, it's not horrible but it's just a PITA. Good luck iBrent!!

 

[iBrent]

Thanks! I'll keep everyone posted with my progress as I am not giving up. It's gotten so bad that I don't drive as much as I used to. It's just too annoying.

 

[iBrent]

So here's my thought. While I was at Autozone today buying a new PCV valve and IAC, I remembered someone on this thread saying that the coil pack can burn out your plugs and wires. Well, about 10k miles after replacing my plugs and wires, I tested the coil pack. Sure 'nuff it tested out of spec, so I replaced it. That didn't change anything so I kept on going. So while I was there today I ordered a new wireset and bought some new double plat plugs. I also bought some seafoam, because to be honest I wasn't all that confident with my cleaning job of the intake manifolds. So I bought 3 cans, one for the intake/cylinders (through the vacuum port), one for the oil (valves/lifters, etc) and one for the fuel system (injectors).

My question is, in what order should I do this? I'm thinking this:

1) Replace PCV valve, clean the hoses around it, and replace the IAC/IAC gasket.
2) Put a can of seafoam in the gas tank and a can in the oil crankcase. Then do the 3rd can through the vacuum port on the intake manifold.
- Run the car for a half tank of gas (~150 miles, probably take a week).
3) Change oil in the car
4) Run the rest of the tank out of gas and fill up
5) Replace plugs and wires

How does that look? I kinda made it up so if that's totally wrong, especially regarding the number of miles in between steps, please let me know.

Thanks again everyone.

 

[yapper]

I've been following this thread so here're my suggestions

Install the plugs and wires first. Bucking/Hestitation is usually ignition system related.

Use a Ford MotorCraft PCV. There's a belief that OEM is better than aftermarket.

Inspect the PCV hoses and use clamps. You mentioned you didn't use clamps before.

While the UIM is off replace the IAC gasket. I'm assuming you're going to take it off especially if clamps have to be put on PCV hoses. You might also want to install a fresh set of UIM gaskets; aftermarket is fine.

Perform the UIM vacuum intake cleaning, fuel system cleaning, and then change oil. I guess 150 miles of driving with fuel and oil additives isn't to bad - if the products allows it.

 

[Desiato]

I replaced my PCV valve tonight and so far my low rpm bucking has been eliminated and hesitation has been greatly reduced. It didn't solve all of my issues, but it had a greater effect than I expected. I have other maintenance to perform for the rest of the issues (plugs/wires/fuel filter/uim cleaning/etc).

I didn't replace the hoses, but it wouldn't have been a bad idea. The next time I'm doing work in that area, I plan to.

 

[getsum111]

Just a FYI, when I did my UIM/LIM cleaning, the Berryman's cooked a couple of the plugs, causing a misfire. So now I do the berryman's, then change my plugs so I don't foul up a new set of plugs.

 

[SHOgoFast]

Regarding genuine ford PCV valves. I went to two dealerships and before I made my purchase I did the "blow through" test to see how well they would seal.

NONE of the brand new motorcraft PCV valves sealed under preasure!!! This is particularly bad for me being turbo as if they do not seal I preasurize the crackcase and blow oil out of the valve cover vents. Now, I did pick up a PCV at pepboys that sealed about 98% when doing the "blow through" test. Just and FYI. It wont make as much of a differece in a N/A car but still. These brand new parts were no better at sealing than my worn out PCV.

Also, when you do replace the pcv clean out the tube that it goes into. If you are going to replace the oil right away you can get cleaner down in there and be okay.

Another thing. When you did the UIM cleaning did you removed the TB and clean the EGR passages that are behind the TB gasket? If not check that out as well.

 

[striker2]

NONE of the brand new motorcraft PCV valves sealed under preasure!!! This is particularly bad for me being turbo as if they do not seal I preasurize the crackcase and blow oil out of the valve cover vents.

i had the same issue after i installed my turbo so i just took a spare vacuum brake booster check valve and put it in between the intake manifold and the PCV valve so that it will still suck air out of the crankcase but not blow air into it. it seams to be working great so far.


iBrent: i was having a hesitation of my own. i checked the resistance of my cam and crank sensors and compared to new ones they were high. i replaced them it seems (so far) to have fixed it. it might be worth looking into considering the cam sensor controls the injector timing and the crank sensor controls the spark timing.

 

[TourDeForce]

Guys, guys, guys....

First, there is ONE thing that nobody has suggested as yet. Clean the MAF. Costs nothing & won't hurt. To check your MAF (before or after cleaning) simply unplug it & go for a short drive. If your problem mostly goes away, you've figured it out.

Second, plug wires. I know you don't wanna hear it, but this statement by iBrent clued me in to the plug wire thingy:

It's weird though, it seems to buck the most during normal driving, but once I mash the gas at WOT it bucks the least.

That is the EXACT problem I had when I mistakenly had my plug wires mis-routed, AND a the same as when I had a wire with a cut in it. Check your frikkin' wires for damage. A sharp edge on the UIM did me in. Double check the routing, the coil leads are not a direct match to the cylinder location.

Since you may have been driving with the car in this condition for a while, please double check your plugs. This kind of mis-fire can easily damage spark plugs and has been a MAJOR PITA for a few guys in the Zetec world. It'll only take a few minutes, so please check them.

 

[iBrent]

First, there is ONE thing that nobody has suggested as yet. Clean the MAF. Costs nothing & won't hurt. To check your MAF (before or after cleaning) simply unplug it & go for a short drive. If your problem mostly goes away, you've figured it out.

I have cleaned the MAF before, with an electronics no-residue cleaner, de-oxit type stuff. But I can definitely do it again. What happens to the drivability with the MAF unplugged and how short should the short drive be?

Second, plug wires. I know you don't wanna hear it, but this statement by iBrent clued me in to the plug wire thingy:

I have new plugs, which will be properly gapped, and I'm currently looking for Ford Motorcraft brand wires. Unfortunately, the only people locally is the Ford dealer, selling them for 122.

That is the EXACT problem I had when I mistakenly had my plug wires mis-routed, AND a the same as when I had a wire with a cut in it. Check your frikkin' wires for damage. A sharp edge on the UIM did me in. Double check the routing, the coil leads are not a direct match to the cylinder location.

I'll check this tomorrow afternoon. Thanks for the ideas!

 

[iBrent]

iBrent: i was having a hesitation of my own. i checked the resistance of my cam and crank sensors and compared to new ones they were high. i replaced them it seems (so far) to have fixed it. it might be worth looking into considering the cam sensor controls the injector timing and the crank sensor controls the spark timing.

How easy are these to get to? I looked on the Autozone help page and it doesn't go all the deep into where these two components are actually located. Perhaps you could help me out a little?

 

[striker2]

well idk where they are located on the duratech so i cant help you out while im here at work but i can certainly look it up on my ford CD when i get home afterwards. IIRC the cam sensor is on the front bank head on the serpentine belt side (i could be way off though)

 

[cje1985]

How easy are these to get to? I looked on the Autozone help page and it doesn't go all the deep into where these two components are actually located. Perhaps you could help me out a little?

I believe they are on the front cover of the engine (by the serpentine belt, should be visible)

EDIT:
from the ONP 99M03 recall
pic: http://www.contour.org/FAQ/recall/99M03/Recall-ONP 99M03_files/r99m03r_files/99m03f07.gif
description:
FOLD-OUT 3 (3 OF 3)

LEGEND

1. OIL PRESSURE SENSOR CONNECTOR
2. CRANKSHAFT POSITION SENSOR CONNECTOR
11. FRONT OXYGEN SENSOR AND CAMSHAFT POSITION SENSOR CONNECTORS
12. ENGINE CONTROL HARNESS CONNECTORS
26. IGNITION CONTROL MODULE CONNECTOR
27. HEATED OXYGEN SENSOR RELAY CONNECTOR

 

[TourDeForce]

Quote:
Originally Posted by TourDeForce
First, there is ONE thing that nobody has suggested as yet. Clean the MAF. Costs nothing & won't hurt. To check your MAF (before or after cleaning) simply unplug it & go for a short drive. If your problem mostly goes away, you've figured it out.

I have cleaned the MAF before, with an electronics no-residue cleaner, de-oxit type stuff. But I can definitely do it again. What happens to the drivability with the MAF unplugged and how short should the short drive be?

The short drive should be long enough to confirm if your bucking & hesitation has gone - just don't flog the thing. A car that is in good running order runs almost normal with the MAF unplugged. You'll loose a little power & there might be some slight hesitation because the MAF isn't sending any info for the fuel mix adjustments, therefore timing gets pulled & fuel mix is done at the upper O2 sensors and run from the mix tables vs rpm, throttle position, etc.

You could theoretically run the car however long you want without damage if you're not aggressive behind the wheel. If it takes you a trip around the block to confirm the bucking is gone (or not), great. If you have to take it on a highway run for 15 miles, that's OK too.

 

[iBrent]

UPDATE:

Replaced PCV valve, cleaned PCV passage to intake manifold.
Replaced IAC and IAC gasket (genuine ford parts from Bill J.)

No change.

Did what was suggested, ran car with the MAF disconnected. It was horrible. Ran really bad, lots of hesitation.

Now what if this problem is not an engine issue? What I mean is, it doesn't really feel like hesitation as much as the car bucking back and forth. The engine still sounds solid. I know the sound of a misfire and its definitely not that. When its bucking the engine doesn't make any peculiar noises at all. What if this is in the flywheel, clutch or transmission? Some sort of mechanical imbalance that causes the car to buck back and forth during acceleration? It's gotten worse and continues to get worse even with all the things I'm replacing on the engine. The clutch doesn't slip I know that, but what if some gears are not balanced or something? I don't really know how all that works beyond the flywheel, so this is all just speculation. OR, what if something on the accessory belt is sticking, like the alternator or something, causing unnecessary and intermittent loads on the engine. What do you guys think?

 

[fornetti14]

Take each plug wire off and make sure you have di-electric grease on the plug and the coil. Make sure you feel the "snap" when the plug wire seats on the plug. Still sounds like you have a bad wire in there somewhere. I've fixed 3 cars this way.

 

[iBrent]

Take each plug wire off and make sure you have di-electric grease on the plug and the coil. Make sure you feel the "snap" when the plug wire seats on the plug. Still sounds like you have a bad wire in there somewhere. I've fixed 3 cars this way.

I don't think its an ignition related misfire or hesitation. I think its more a bucking caused by a mechanical imbalance. I'll check those tomorrow in the light, but i'm still convinced its not ignition related.

With a faulty wire, what does the hesitation feel like?

 

[Tony2005]

Try one more test. El cheapo plugged exhaust test. If that doesn't solve the issue, maybe time for a real time live data scan and post the results (it cost about $100 at the shop or buy your own Actron CP9180 for about $200). The cheapest would be to check if you can hook up with some MA CEGers with a real time scanner.

You may have a plugged main catalytic converter.
http://www.contour.org/ceg-vb/showthread.php?t=762

 

[iBrent]

UPDATE:

I bought a vacuum pressure guage tester yesterday. I plugged it into the intake manifold, where the hose comes off and goes to the EVR. Now if I had a vacuum leak anywhere after that point, such as in the green, yellow, and red lines, it wouldn't see it. Where else can I plug my gauge into?

Here were my results from that port:
idle - 19"
3000rpm - 25"

I'm nervouse about doing the el-cheapo exhaust plug test because I've never messed with O2 sensors or anything and I wouldn't know how to fashion up a heatshield. So I read that you can tell the exhaust is plugged based on how much vacuum there is at high(er) rpms. So is 25" normal at 3k?

 

[livelyjay]

i was having a hesitation of my own. i checked the resistance of my cam and crank sensors and compared to new ones they were high. i replaced them it seems (so far) to have fixed it. it might be worth looking into considering the cam sensor controls the injector timing and the crank sensor controls the spark timing.

I just started reading this site, and this thread has been great because my wife's car has been bucking/hesitating for some time now. Her fuel economy sucks as well. The engine light went on yesterday and it was for the Cam Position Sensor. I just picked on up today from Advance Auto and plan on installing it this weekend. I'll let everyone know if it fixes the problem. PCV will come next, after that I'll just move down the line of sensors and valves and replace them all.