Power loss around 4500-5000 rpm

[GEN 3 SHO FAN]

No, they seem not working at low speed on high accel but they will open on accel at high speed...(based on the sound). Sometime, it doesn't give me the normal accel when needed (stay closed or some can be stuck in closed position even if the shaft rotate ?)

However, I wired them open : Me 1 ; Ford 0 but I lost some blood in the project. No bug until now but the temp is cool since (this bug coming on hot day). The next week-end will be hot, I will see how it does.

 

[stephen newberg]

OK, keep us informed as you give it a try. There is some mechanic saying that if you did not end up cut and bleeding, you must not have done it right.

pax, smn

 

[GEN 3 SHO FAN]

Ok, I go to Ontario this week-end (a hot one, 88 degree) and I can say it's not IMRC related. They were wired open and the box unplug all the time.

On the run while the return (highway), I remarked when I needed a kickdown, the RPM goes up but no power at all. Seems the torque converter doesn't want lock up. If let the gas a little, the transmission return in overdrive and TC lock giving me a very light accel... And when I have others car all around forcing me to adjust my speed (a little gas, no gas, a little brakes), the TC seems to have hesitations. This happpens only when the trans is hot and running for a while.

If I put a bigger cooler, is it useful in this case or the trans is going away no matter what ? Ford seems to understand lately because on 2001+ SLO the factory trans cooler is bigger and it's finned (mine isn't finned, just a tube...).

 

[stephen newberg]

Oh well, so much for the easy fix.

However, I am unsure about your report in other ways, as normally what happens is that the Torque Converter has to unlock to give you the ability to accelerate. When it locks up, that is when you RPM drops. Is this what you mean and we are just having a language confusion?

Overall, it is starting to sound like transmission problems, though. A lot of these cars got used as if they were stop light racers and as a result there can easily be premature transmission failure. It certainly cannot hurt to have a greater cooling capacity for the transmission, but it is starting to sound to me like you already have slippage there and it might be getting to rebuild time, or if the transmission has already been rebuilt, time to take it back to that shop and start complaining.

pax, smn

 

[GEN 3 SHO FAN]

I will first try a bigger trans cooler. Do you have any suggestions that will fit in place of the front one (tube) ?

I found how to remove the IAT semsor from the air box, you have to rotate it. I will try that too.

 

[stephen newberg]

I picked up a transmission cooler from FPS and it works very well. I do not know if they still have more or not. Actually, I cannot find them in a quick Google search, so they may not be around any more. You will just have to do some searching about, I guess. Most of what I have found looking about quickly is very old.

pax, smn

 

[SHOdded]

I thought Doug was on this forum, no?

http://www.fordspecialists.com/contactus.html

Street Address

Ford Performance Specialists Inc.
351 Six Flags Pkwy SE
Mableton, GA 30126

Hours: 9am - 6 pm
Monday - Friday

Phone: (770) 949-7191
Fax: (770) 485-9738

[email protected]

https://www.youtube.com/channel/UCqcOANzO9zwbZ29EvXSN84A

 

[stephen newberg]

Ah, excellent. Thank you. I was a little surprised when he did not come up on a Goggle search. I should have tried the full name rather than the initials.

pax, smn

 

[SHOdded]

Long time since I Googled him as well Took me a couple of minutes, that's like molasses on internet time!

 

[GEN 3 SHO FAN]

Thanks guys,

I just purchased some subframe bushings from Rockauto and I realized the change rate with Canada going worst and worst. I decided to find one in a scrapyard (I found something that will made the the job for 2$).

I replaced the IAT sensor nothing changed.

I found this on V8SHO.com :

"...Cams welded, I've been trying to diagnose this problem also with not much luck. No vacuum leaks I can detect. Compression is fine.. I've narrowed it down to a sensor or sensors. Threw 2 O2 sensor codes Bank 1 sensor 2 malfunction and Bank 1 Sensor 2 heater circuit malfunction. Now the car misfires bad but I've narrowed it down because its running rich as ****. At idle at a stop light or anything I can smell unburnt gas through the exhaust, so which tells me something is fubarred and telling the computer its at WOT when its at idle therefore the cylinders load up with fuel and wala you got the misfires. If I get on the gas hard it will usually stop after 4K RPM when its actually at WET (WOT?) and using all that fuel. Good 'ole computers !"
-Jon
http://www.v8sho.com/SHO/CarMissesChangedPlugsCoils.htm

But I have no O2 sensors codes... I will check for fuel smell.

 

[GEN 3 SHO FAN]

Ok, I rebuilt all the front of the car and I put a auxiliary trans cooler with 2 factory finned tubes (one replacing the rusty metal hose behind the radiator). I took the time when the trans hose was unplug to change transmission oil. I know my prob can be one of trans because it's heat related too.

I started the car (motor cold during a cold summer day) and the oil coming out had many small bubbles in it... I'm wondering if it's normal ? Is it a symptom of a defect in the trans ? It was a cheap oil replacement of Mercon V I bought at the start of this summer (I put Mercon V after).



Thanks for your replies guys,

 

[SHOdded]

That fluid should be quarantined immediately! An outbreak is in progress! J/K

Possibly some foaming going on? Are you sure you put in the correct amount of fluid and that there are no leaks of any kind?
http://diybuildingandrepairs.com/auto-repairs/air-bubbles-transmission-fluid.html
http://www.justanswer.com/dodge/0sc8j-bubbles-transmission-dip-stick-fluid-level-transmission-issue.html

 

[GEN 3 SHO FAN]

Ok thanks, the front hoses were unpluged from some days while I replace all the rads. The trans loose many liters during this process by gravity (like 5 or 6) but not all because we have around 12 liters in it. I started the car (after many days) to retreive some more oil (another 3 or 4 liters) but with bubbles this time... It's normal then.

Thanks for the infos, I'm not a mechanic but I do my best to keep it on the road.

 

[GEN 3 SHO FAN]

Ok, back again with this problem. During these repairs I also repaired the secondary air pump causing P1413 code. Moreover, I replaced the gas tank to eliminate the P0453 code because the pressure sensor was missing on it. I have no more code on the car.

Tryed the car, nothing changed. The bug commonly coming at 4000 rpm depending on the ambiant temp. Sometime, the torque converter just seems to disengage (no power at all) and sometime it seems to be lock one second the other not, when it's occurs I just have to retreive gas on the pedal and the t/c return to his place correctly. But it doesn't seems to me to be a trans prob, it will shift perfectly in all gears at low/medium rpms and in cold conditions. It's driveable but it doesn't offert performance like a sport car.

I tought a lot about that recently and I remembered that this bug came after I replaced all rear coils and cleaned my intake... The car shift perfectly in all conditions and rpms range before this maintenance.

4 things coming on my mind :

1) When I replaced the coils (for news ones), I also replaced the plugs and for one, I heard a little "tick" when I bolted one to the motor. After some time, I'm begining to had a misfire. I checked my rear bank and I found that the "tick" plug craked badly on the white ceramic part. I changed the plug but not the coil... Does the coil going bad because of this ? I must say that I have no misfire at low or high rpms...

2) During this operation, I had to seperate the rear wiring from the head with a screwdriver because it was frying on it... I put some plastic protection between head and wiring but not between each wires. Maybe some wires lost their protection and causing electricals probs or noise to PCM ?

http://www.shoforum.com/index.php?threads/cop-harness.107677/#post-1154424

3) When I cleaned my intake, I found my 2 gaskets between runners and lower intake were a little rusty and I put red silicone on them just to be sure to doesn't have a leak there. Maybe I have a leak there because I put too much silicone... What are the effects of a leakage on the intake (motor sucking air somewhere) on motor performances ?

4) At the same period, I also changed the gas tank. We replaced the old gas pump (136 000 miles) in the new tank which is difficult to put in the tank mostly because of the gauge and the filter. Maybe the pump is going away but I rarely rode something about a bad pump and when they go bad, they just stop working... (Edit : the car always starts at the first try, no pressure lost on the line.)

I will be very gratefull to have yours advices and past experience on that kind of probs. I'm begining to be very tired of this, I have this car for 2 years now and it's worked correctly only a few months...

Thanks guys,

 

[stephen newberg]

I do not think #s 1-3 are likely to be causing what you describe, but 4 is possible. If the fuel pump is not keeping up with demand, yes, you might start getting stumbling at 4000+ rpm. Or, it is also possible that the problem is completely new and not associated with your prior work, in which case looking into the transmission itself might be a place to start.

pax, smn

 

[GEN 3 SHO FAN]

If the rear wiring is toasted, any of the 4 coils can be short cut and then send false information to PCM... I found a Kirk Doucette old reply from 2007-8 saying that the wiring issue happens often and happens more often as these cars aging. I will check that for sure.

Edit : I found another old reply from saying that if the coils are fireing back to the PCM, it can then shut down defectives coils resulting in a loss of power (the car can run on 4 cylinders).

Is a plug which taken lot of oil can be a problem ? I retreived some oil from a plug well, I cleaned all and changed the coil but I kept the plug.

 

[stephen newberg]

Never hurts to check, but normally when you have shorting of this sort causing problems, it is not something that comes on at particular rpm levels, but is rather more constant.

Similarly, it is not likely that having had oil on the plug is going to matter much if you have cleaned it all up and the plus is still working at all, though if it was an old plug and had cracks, it is possible that under the higher load of greater RPMs it might start to break down. If it was a new plug, I doubt the problem is there, though, of course, every now and then you do get a bad plug from the factory. Very rare, though, these days.

pax, smn

 

[GEN 3 SHO FAN]

Ok, this plug is in the front head, I will replace it even if she is 1 year old.

I talked to my mechanic, he said that a vacuum on the intake will gives higher rpms on the motor which isn't the case... Someone experienced different behavior with that kind of probs ?

Some people had probs with the rear harness.

http://www.shoforum.com/index.php?threads/cop-harness.107677/#post-1154376

Edit : Many wires pass on the rear head, one of them is the wire of the turbine shaft speed on the transmission...

 

[GEN 3 SHO FAN]

Ok, we checked the fuel pressure this week.

32 psi at idle (correct ?)
40 psi max (without vacuum plugged on the fuel regulator) which is correct spec as I rode

but Sperold, SHOZ123 and others said here that the fuel pressure must be above 35 psi normally (on idle I presume)
http://www.shoforum.com/index.php?threads/99-sho-wont-run.129766/#post-1426642

Someone knows if 32 psi is correct or I found the prob ? I have no modifications on fuel system. Always starts at first try and idle runs smooth (even with IMRC opens).

Thanks guys,

Edit : The normal pressure is really 32 at idle and 40 at max. This problem was related to a bugged fuel pump which create a fuel pressure drop when pressing the gas pedal aound the half. The problem never return after pump replacement.