ROUGH RUNNING AT HIGHER RPMS

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bluebird02
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Joined: Sun Dec 20, 2015 9:22 am

ROUGH RUNNING AT HIGHER RPMS

Post by bluebird02 »

I just recently bought a 2002 Thunderbird. The previous owner truly enjoyed this car,(152000) but was not to good with maintenance. The car needs TLC and such, but the main issue is, it starts and idles fine and sounds great, but once I get over 2500 rpms, it starts running rough and really only gets up to around 45 mph. The car is currently up on blocks, so I can redo the brakes and suspension and some minor interior repairs. The car was supposedly put on a engine analyzer just before I bought it and no codes were found, but showed a slight miss with one coil pack. Here is a list of all the things I've cleaned, replaced of just plan worked on to try and get this high rpm issue solved, to no avail.
First I did check for any leaks or disconnected hoses, all appear to be good
Cleaned Throttle body with correct cleaner
Replaced Idle air control valve
Replaced EGR valve
Replaced Crankshaft positioner
Replaced all 8 Coil Over Plugs with new spark plugs
Replaced Throttle position sensor
Replaced Gas Filter
Added 93 octane gas to fill tank and added octane booster
The engine actually idles better and sounds smoother, but it still seems to run rough when I give it high rpms. I can't drive it at this time, due to the wheels and brakes are off, but I can give it gas and still at about 2000 rpms, it starts to break up and run rough. My next attempt was to replace the Temp sending sensor, but once I found out that you have to remove the intake to get to it. I decided to buy a engine analyzer and test it myself.
Some might ask, "why the hell didn't he take it in before it went up on blocks", I guess I just trusted the seller when he stated that the issue was just a bad coil. Anyways, if anyone has any constructive ideas or suggestions, please post them. I need all the help I can get.
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redstangbob
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Re: ROUGH RUNNING AT HIGHER RPMS

Post by redstangbob »

I liked this for scanning OBD II Fords http://www.vintagethunderbirdclub.net/p ... 32&t=12600 You didn't mention testing fuel pressure, at 152K you could have a pump/regulator problem. good luck, Bob C
It's gonna be cool when it's done
And now it's really cool !!



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bluebird02
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Re: ROUGH RUNNING AT HIGHER RPMS

Post by bluebird02 »

Bob, thanks for the advice. No I actually didn't check the fuel pressure. I will have to give that a try. Thanks also for the advice with the scanner. I checked it out and it looked good, but I just purchased a Equus 3160 scan tool. It was a little pricey, but I have 12 different cars, so I figure I can get additional use out of it. It hasn't arrived yet, but as soon as it does, I will scan the codes or info. Thanks
bluebird02
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Re: ROUGH RUNNING AT HIGHER RPMS

Post by bluebird02 »

Well, I got my new Innova engine OBD2 and found only one code. P0122, throttle positioner low voltage input. Changed the throttle positioner and cleared the code. Still did not run correctly. Ran the OBD 2 again and no codes came up, but the engine still does not run correctly. Spoke to my mechanic and he suggested a new MAF as opposed to just the cleaning I did. At this point I do not have the struts or brakes down, so I can't even move it to his shop. Ordered a new MAF and am crossing my fingers.
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redstangbob
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Re: ROUGH RUNNING AT HIGHER RPMS

Post by redstangbob »

I want to be gentle with you on this subject, but I'm only trying to help. I looked at the scan tool you purchased, it didn't appear to support mode 6 diagnostics (maybe it does). Did the MAF test OK? if that tool can test it at all. did you do a fuel pressure test? I do this work every day, take it from me you want to test before buying parts. I hope things all work out for you, and you'll enjoy your car.good luck, Bob C
It's gonna be cool when it's done
And now it's really cool !!



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bluebird02
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Re: ROUGH RUNNING AT HIGHER RPMS

Post by bluebird02 »

That was very gentle, anyways, I bought the Innova 3160 scanner. Considering I've never used a scanner before, I was told this is a decent one for the price and a backyard mechanic. Either way, it seemed to show that it scanned several different engine systems. The only thing I have not done is tested the fuel pressure. I just ordered a fuel injection tester (as I only have one for non-fuel injection) and will test it as soon as it arrives. Also, its to late on the buying parts thing, I've already bought many parts trying to resolve this issue, but I will not give up. I love the looks of the car and the engine sounds great at idle, but it just will not run correctly with anything over 2000 rpms. If the MAF doesn't fix it and the fuel pressure checks out OK, I am going to finish the strut and brake replacement and take it into a shop. There is not anymore I can do in my garage., Thanks again for your help.
bluebird02
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Re: ROUGH RUNNING AT HIGHER RPMS

Post by bluebird02 »

Well, the new MAF sensor did not make a difference. Still runs rough over 2000 rpms. I also received my new fuel injector pressure testing gauge and the fuel pressure is only 30 psi at idle and doesn't go above 40 psi when I give it gas. From my research, it should be between 30-65 psi. I already have a new fuel filter, so my guess is it's the fuel pump. Considering that it appears to be the original pump, that would make it 14 years old. I purchased a new one and am waiting for it to be delivered. In the mean time, I'm trying to get the locking cap off the fuel pump. If anyone has done one before, any suggestions might help, considering that its down in a small well behind the passengers seat. I can't get any type of hammer or channel locks in there to open the cap. I did order a special cap remover tool and am also welding up one that might work. The cap is on very tight, the first cap remover I made out of metal actually bent before even moving the cap. This next one is being made with thicker metal. We'll see.
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redstangbob
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Re: ROUGH RUNNING AT HIGHER RPMS

Post by redstangbob »

Uh-huh, you might be going in the right direction. Do some research on-line for testing the fuel pressure regulator, and be sure that side of the system is good. Can't help with the lock ring, never had one give me too much grief. good luck, Bob C
It's gonna be cool when it's done
And now it's really cool !!



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bluebird02
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Re: ROUGH RUNNING AT HIGHER RPMS

Post by bluebird02 »

I used my improved home made cap remover and got the cap off. Now, I'm just waiting for the new pump to arrive. I pulled a used pump out of a Lincoln LS and it looks identical to the Thunderbirds, but I think I will just wait for the new one. I am going back to the recycle yard (politically correct for JUNK YARD) and pull the fuel pressure sensor (regulator) off the engine and try it on mine. Removing the used sensor should not be a big deal and the price should be very little.
I guess the way I have to figure all these good used parts left over is, I plan on keeping this car for some time and I will have all these spare parts available for years to come, Ha Ha. Plus, with all the work I've done on this Bird, I will know how to fix just about everything on this car. Anyways, I hope to get the new pump before this weekend, if not, I will not be able to install it till next month. It really doesn't make a difference, it's do cold to be driving the T-Bird anyways.
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redstangbob
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Re: ROUGH RUNNING AT HIGHER RPMS

Post by redstangbob »

Plus, with all the work I've done on this Bird, I will know how to fix just about everything on this car
Keep thinking positive, those cars are pretty complicated :cool: Did you pick up a set of shop manuals for your car? ebay has them here and there, if you keep the car I'd definitely get the set.
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And now it's really cool !!



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vince
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Re: ROUGH RUNNING AT HIGHER RPMS

Post by vince »

If problem continues, check the ports going into the EGR. These can clog with carbon and can be mechanically cleaned with very stiff wire. Also, you say you changed the plugs. Did you inspect the boots? These cars did have a problem with water intrusion. It was run off from the cowl on to the valve cover. A new style cover was designed to solve the problem. I think you'd have the check the part number of the cover you have with a dealer to determine which style you have (TSB 07M07S1). You might also consider having your mechanic hook up his computer and run a balance test. You could have a cylinder or two running a little below spec, you won't necessarily get a misfire code for this as the cylinder is firing, just under powered. Just a couple of thoughts. Good luck.
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bluebird02
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Re: ROUGH RUNNING AT HIGHER RPMS

Post by bluebird02 »

Vince, Thanks for the advice. Along with changing the plugs, I replaced all 8 of the COPs, so all the boots are new. I also replaced the EGR valve and checked the port at that time. It was actually very clean. Today I picked up a so called good used fuel pressure sensor and will replace that with the new fuel pump. If that doesn't fix it, I still have to reinstall all new struts and springs and brakes, but then I am going to take it into my mechanic. At this time it is not drivable. Thanks for the help and I will post my results.
bluebird02
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Re: ROUGH RUNNING AT HIGHER RPMS

Post by bluebird02 »

Replaced the fuel pump with a new one and the fuel pressure sensor with a good used one. Same result, runs rough at mid to high RPMs. I have to finish replacing the rear brakes and suspension parts (the fronts have already been done) and then I'm taking it in to my (when all else fails mechanic) He is very good and hopefully can find out this issue. After talking to him about this problem, he seems to think that it might be a wiring issue. In all fairness, this will be the first time that I've taken it to him. So hopefully his expertise can determine the issue as well as save me some labor costs. He fits me in between standard brakes jobs and such. I will keep you informed of the results.
bluebird02
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Re: ROUGH RUNNING AT HIGHER RPMS

Post by bluebird02 »

It's running great, I'm enjoying it daily. I wish I could tell everyone what was wrong, but all I can figure, it was a combination of things. I decided to take it out and drive it before taking it to my mechanic. It started by running poorly again, but the more I drove it, the better it was running. I did fill the gas tank before I started working on it and it did not seem to make a difference. I also added several bottles of Seafoam and Racing Fuel (maybe that had something to do with it) anyways, it took about 40 minutes of driving the bird till it was running smooth and accelerating correctly and not running rough. Never did take it to the mechanic. Crossing my fingers that whatever the problem or problems were, they are gone. Love driving this car and can't wait till spring for some top down cruising.
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redstangbob
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Re: ROUGH RUNNING AT HIGHER RPMS

Post by redstangbob »

Part of the Ford EEC system is the personality module, or adaptive module. It will adjust the mapping to the way you drive and the engine's condition. You probably hit on the right combination of bad components and after driving the module may have adjusted again. This can also be done by disconnecting the battery for 15 minutes on many cars, I wouldn't bet my life about that retro-bird though. Glad it's up and running, good luck, Bob C
It's gonna be cool when it's done
And now it's really cool !!



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