Community Forums

tiffy2000 · 02-24-2019, 07:35 AM

Just throwing this out there, someone on a Ford truck forum had a sporadic issue, threw a bunch of stuff at it and it turned out to be a 5-star issue , put it back to stock and issue went away, I think 5-star made it good for him

Ndrorder · 02-24-2019, 09:02 AM

Couple thoughts . . .

When a shop cannot recreate an issue, you sometimes have to take them on a drive and demonstrate the issue. Doesn't mean they will be any more interested in solving the issue.

The correct obd2 tool to diagnose an issue that doesn't create codes must have the ability to display the live data from the vehicles sensors. If it's a tps issue, you'll see the throttle body voltage bouncing around. Many have this ability, but they don't state it well online. You're local autozone, oreilly, advance auto, etc. Will have one on the shelf and be able to tell whether it has the live data monitor feature.

SuperGewl · 03-03-2019, 10:45 PM

Quote:

Originally Posted by 890ken

You might also have a bad coil pack or spark plug boot. Had 2 fail on my 1999 V-10. Would shudder under load unless I downshifted and let it run at high RPM. The rubber boot which covers the connection between the coil and the plug can deteriorate which causes misfires on that cylinder. In my case I had 2 coil packs that would break down under load. If you have the correct diagnostic OBD2 reader, it will tell you which cylinders are misfiring. Or you can take it to Ford and they will fix it for $$$$$$. Or, just buy 1 coil and boot assembly, replace #1 coil and see if it gets better. If not, put old ones back and put new on in #2. Keep on doing that until it gets better. Might have to buy more than 1 coil to get it all fixed.

Stop being cheap, they are over 10 years old and need replacing anyway, so do the plugs. Do your required maintenance and it will run right.

TeJay · 03-04-2019, 09:44 AM

Changing the coils and plugs was something mentioned in post #11 based on the age of his RV. If he chooses not to do then so be it. Generally speaking a code reader won't tell you much about misfires unless it happens enough to cause emission issues.

Common sense has to prevail. If every time you had a misfire it turned on a code light can you imagine the number of vehicles in shops for little to no reason?? Remember when the scheduled vacuum checks for the evaporation system brought scads of vehicles into the dealers with loose gas caps? The dealers were overwhelmed.

A code reader that streams live data is only as good as the person reading it.

wildmanbaker · 03-04-2019, 01:16 PM

TaJay is correct. A code reader could help rule out sensors as the possible cause, but will not tell you how to fix it, or what the problem is. It is very hard to diagnose a problem on line. It is fairly hard when you are talking to the customer face to face, actually find what the problem really is, as different people will focus on different symptoms.

Pirate · 03-04-2019, 05:01 PM

Before you hook up a code reader, make sure you go back to stock if you have a custom tune installed. I had some erroneous readings when I tried to read codes with 5star installed such as only 8 cylinders and wrong o2 sensors. This could be dependent on the type of reader though, bluetooth vs. wired, I'm just not sure. Perhaps 5star will comment on this.