Im getting a real bad hesistation at just off idle when shes cold. What could we be looking at?

A car that needs to be warmed up a little bit before being driven perhaps

It sure seems that your Mark VIII has a lot of problems. Are you sure it only has 71,000 miles on it? Has it been well maintained? Just currious.

It sure seems that your Mark VIII has a lot of problems. Are you sure it only has 71,000 miles on it? Has it been well maintained? Just currious.

yea its well maintained...the problems are problems that never get cured, i just keep trying to solve the situation. this problem has been arround for 2 years now. im not 100% on the 71k, but carfax says so. im bout 99% on the 71k.

Check your fuel pressure.

My Mark 8 has 140,000 miles on it and I have not had hardly any problems with it, I must have got a good one.....:)

Check your fuel pressure.

stupid question, but how do i go about doing that, i havent done that one yet.

Put a fuel pressure gauge on the schraeder valve of the fuel rail.

is that it?

Yes, it is that little thing that has a black cap on it. Just twist that off.

I've noticed my Mark likes to be warmed up before getting on it. That's just how fuel injection is until it warm up completely. When first started cold, your engine runs in what is called "open loop." This is a basic factory program that tells the computer how to run your engine until it warms up. Not the best for performance, but best for your engine until it properly warms up. After your engine has warmed up, your computer will enter the "closed loop" and rely on all of the sensors to properly regulate fuel and timing demands.

You should always let your engine warm up completely before romping around. This also goes for your transmission. They like to be warmed up before abusing them.

:I It's never good to floor it on a cold engine, it is not good on all those rapidly expanding internal parts.. my car also likes to be fully warmed up before it will make full power.

cuz off idle is flooring it.

I came across a Tech link that had stated that the MK VIII engine should be at least 140 degrees before hammering on it. It gives the aluminum the chance to fully expand to keep your gaskets in palce.
Whether fuel injected or carb, the engine needs to be brought up to operating temp before any rated values can be met or reliable performance can be expected.

cuz off idle is flooring it.
dude, don't be a tard, if it's off idle than maybe you should check your TPS voltage.

and if that doesn't fix the problem try adjusting your muffler bearings with a metric crescent wrench.

and if that doesn't fix the problem try adjusting your muffler bearings with a metric crescent wrench.

i thought muffler bearings used Torx bits for the adjusting rod...?no?

and if that doesn't fix the problem try adjusting your muffler bearings with a metric crescent wrench.
A metric crescent wrench :D

dude, don't be a tard, if it's off idle than maybe you should check your TPS voltage.

dude! iv done that, my tps is only one year old. im getting codes that show low voltage on tps egr and maf...and since the tps is new, its more than likely a bigger problem than the individual sensors.

So, Mr. Wilson. If your car is only missing "off idle" when it is cold, what does it do when it is warmed up?

So, Mr. Wilson. If your car is only missing "off idle" when it is cold, what does it do when it is warmed up?

its a hesitation when cold, and rough when warm. always has been rough idle, but the hesitation is new.

dude! iv done that, my tps is only one year old. im getting codes that show low voltage on tps egr and maf...and since the tps is new, its more than likely a bigger problem than the individual sensors.

What about the egr and the MAF? Are they new also? The only real way to attack a problem is a systematic approach. You are getting codes, for the TPS, it is new, could it still be bad?? Possibly. But you are also getting the other codes. Try eliminating those as the possible cause of the codes. You usually can't eliminate all of the issues that you are getting codes for by just replacing one bad part. Wishful thinking.

It is very true that any internal combustion engine should reach operating temperture before being flogged. And that includes everything from way tiny little hobby engines to way big humongus navy destroyer powerplants. Maybe, just maybe Mr. Wilson, it is you that is your Marks worst enemy. Not picking on you, but from the list of issues that you have gone through, you either have one of the worst lemon Marks in history, or you just plain beat the hell out of that poor car.

What about the egr and the MAF? Are they new also? The only real way to attack a problem is a systematic approach. You are getting codes, for the TPS, it is new, could it still be bad?? Possibly. But you are also getting the other codes. Try eliminating those as the possible cause of the codes. You usually can't eliminate all of the issues that you are getting codes for by just replacing one bad part. Wishful thinking.

It is very true that any internal combustion engine should reach operating temperture before being flogged. And that includes everything from way tiny little hobby engines to way big humongus navy destroyer powerplants. Maybe, just maybe Mr. Wilson, it is you that is your Marks worst enemy. Not picking on you, but from the list of issues that you have gone through, you either have one of the worst lemon Marks in history, or you just plain beat the hell out of that poor car.

well, im quite sure its a lemon, cuz i got the car with 42k, and im the 6th owner...so theres obviously a reason everyone dumped it.

My thinking is that its something other than those individual parts, because it all failed at once.

well i just pulled the codes again, cuz i keep getting the check engine light now, instead of every once in a while, its quite often. No new ones, but i dont have the TPS low voltage again.

well i just pulled the codes again, cuz i keep getting the check engine light now, instead of every once in a while, its quite often. No new ones, but i dont have the TPS low voltage again.


Do list all of your "new" codes individually. Sounds like you have a low voltage issue that stems from a low battery or Alternator. If I were you, I would begin a methodical search of every ground connection on the car. Do a votlage drop check at every ground tap to see if the issue lies in that.
Its not a bad idea to look at the cables that come off of the battery to see if they are in good shape. More than a cursory "visual" check, mind you. Get in there and move the cables around, looking for corrosion, splits in insulation or anything that feels or sounds funky.
After you have posted all of your numbers as accurately as possible, that should help the rest of us w/ potential suggestions.:cool:

:I I think Mr. Wilson should take an automotive course at a vo-tech this summer. Mr.Wilson--you should really consider this. All of the questions you ask involve systematic approaches to problems most people don't think about. You keep mentioning these codes: Do you know what these codes really mean? Every mechanical device is prone to failure eventually. This is how the universe operates. Because of this, diagnosing any internal combustion engine involves the same process. A computerized system does potentially contain more problems and headaches, but the same, systematic approach still qualifies. Start with the basics and move on. Don't just start replacing things because you interpreted a code said something was bad. If you don't take a course, at least go to the library, or Barnes and Noble, or someother place and check out a book about modern electronic control systems found in automotive systems.

Just a little FYI...my car had the same problem you are experiencing, but it basically had been sitting for 3 years. I changed the spark plugs, wires, and ran a lot of B-12 in the fuel system. It cured my hesitation when at proper operating temperature and the miss went completely away. While you're at it, replace your fuel filter as well.

Do list all of your "new" codes individually. Sounds like you have a low voltage issue that stems from a low battery or Alternator. If I were you, I would begin a methodical search of every ground connection on the car. Do a votlage drop check at every ground tap to see if the issue lies in that.
Its not a bad idea to look at the cables that come off of the battery to see if they are in good shape. More than a cursory "visual" check, mind you. Get in there and move the cables around, looking for corrosion, splits in insulation or anything that feels or sounds funky.
After you have posted all of your numbers as accurately as possible, that should help the rest of us w/ potential suggestions.:cool:

already done all that. perhaps not EVERY single ground, but the main ones that would have the most effect on those particular systems. not only me, but other mechanics too.

:I I think Mr. Wilson should take an automotive course at a vo-tech this summer. Mr.Wilson--you should really consider this. All of the questions you ask involve systematic approaches to problems most people don't think about. You keep mentioning these codes: Do you know what these codes really mean? Every mechanical device is prone to failure eventually. This is how the universe operates. Because of this, diagnosing any internal combustion engine involves the same process. A computerized system does potentially contain more problems and headaches, but the same, systematic approach still qualifies. Start with the basics and move on. Don't just start replacing things because you interpreted a code said something was bad. If you don't take a course, at least go to the library, or Barnes and Noble, or someother place and check out a book about modern electronic control systems found in automotive systems.

Just a little FYI...my car had the same problem you are experiencing, but it basically had been sitting for 3 years. I changed the spark plugs, wires, and ran a lot of B-12 in the fuel system. It cured my hesitation when at proper operating temperature and the miss went completely away. While you're at it, replace your fuel filter as well.


dont think im some 10 year old tinkering with daddys car, iv done everything i and many other people can possibly think of, short of changing out the maf/egr. I would be willing to put my wrench against many a man(or woman) out there. Now, im not saying im the best, but im no newb either. the only reasons i havent changed out the egr/maf is because it just doesnt make sense that they (and the tps, which has now magicaly stopped throwing) failed at the same exact time.

So have you done your votage tests? Have you checked the ohm signals and votage signals from your MAF and TPS using an accurate DVOM? Have you checked for drains, shorts, corrosion, bad solder joints, bad pins, internally corroded wires? Have you checked your reference voltage from your computer to these components? Have you ohmed all of your ground wires or all of the wires coming from the plug to the computer to the components?

I wasn't impying earlier you were a 10 year old tinkering with daddy's car. Knowledge is an effective tool and weapon against mechanical and electrical demonds. My suggestion for you to take a class would hone your skills and enable your efforts to repair your car more effective.