lose power at 3000 rpm
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Red88 RICK
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so whatw as the outcome fo this because im going throught the same ting right now i just got throught having a bad new TPS (surging idle) code 63 and now have code 94 which was displayed right after clearing codes and i havnt checked recently today for any new ones. i ahve nice idle and power but right when i get to exactly 3000 RPM it feels extramly wierd liek the car just dosnt pull anymore witht eh old tps i ddint notice this at all... iv only tried it durring WOT im going to give it a shot just normal throttle tomoarrow the if you ned anymore info to help me ask please and THANKS
I've had a thread going with what sounds to be the same problem for about a year now:
Looking for some diagnostic help on my ’95 GT 93,000 mile 5.0 motor with a stock intake system (except for K&N filter) and a Mac shorty / Flowmaster cat-back exhaust. In other words, a basically a stock original motor w/o many mods.
The car runs great except above 3000 RPM at wide open throttle. About 2000 miles ago I had some intermittent starting problems so the fuel pump, idle air control valve, ignition control module (not the computer), ignition coil, and fuel filter have all been replaced. (Replacing the ignition switch finally fixed the problem….). The car has been fine up to about a month ago.
For normal everyday driving the car is fine. If you run it up to 4500 at part throttle it’s fine and it will run continuously (cruise) at 4500 without a problem. It’s when you punch it and try to rev it above 3000 RPM that it has a problem. In other words, it will run up to 4500 fine with a part throttle but if it’s WOT (floored from a take off) it will run up to 3000-3500 RPM and then act like it’s running out of fuel above approximately 3000 RPM. It will start to die and loose power at 3000-3500 but momentum will carry it up to about 4500 (starts acting up about 3000 but will still rev up to 4500) but by then it’s dying enough to slow itself back down. If you hold it WOT it will continue to slow itself back down just like it’s running out of fuel. If you back off to part throttle at any point it’s fine and will run at 3000, 3500, 4000, what ever you want, but as soon as you step back down to WOT it acts like it’s loosing it’s fuel flow and begins to die again. I really don't believe it's a fuel issue though so the best way to describe it is to say it feels just like a rev limiter is kicking in or the advance is being pulled waaay too far forward or something. It's like it's a rev/vacuum controlled type issue.
No check engine light is showing and the fuel pressure regulator seems to be operating ok (I have a fuel pressure gauge mounted on the rail and at idle the PSI bumps up with the vacuum line disconnected like it should). With a new fuel pump and fuel filter, new ICA, and new ICM in the car and the regulator appearing to work I don’t really know where to go from here. It strikes me as a computer control/signal issue or some sensor like maybe the throttle position sensor type issue. I just hate to just throw money at new parts (particularly the computer) and hope something fixes it.
Anyone had this problem and know how to fix it!
About midyear I posted this:
Quick recap....
Replacement/check recap:
Car driven approx 2500 miles in the last 2 years, all replacements parts have less than 2000 miles on them. K&N filter, headers, Flowmaster cat-back are only intake/exhaust mods. No fault codes showing up on computer.
MSD 8MM Heli-Core wires, cap, and rotor replaced by previous owner. Have approx 8-10,000 miles on them with no apparent shorts. Have checked and cleaned cap, rotor,and distributor internals
When purchased car had intermittent starting issue so replaced:
New IAC - Idle Air Control Valve
New Ignition Coil
New ICM -Ignition Control Module
Added fuel gauge on rail, fuel pressure regulator increased PSI w/o vacuum but still decided to replace fuel pump. Everyone swore it was the fuel pump.
New Fuel Pump - standard flow Carter
New Fuel filter
New Ignition switch. Ignition switch fixed it!
Started having WOT throttle issue last summer
New Spark plugs (Motorcraft with factory .052 gap)
New Air filter - changed K&N out for stock Fram paper filter and cleaned MAF twice
Pulled distributor top apart, clean and no apparent loose/broken internals
TPS- Throttle position sensor checked ok, was .96 volt at idle to 4.69 at WOT
ACT - Air Charge Temp sensor is 60.1K ohm @ 49°F (within spec)
ECT - Engine Coolant Temp 4.67K ohm @ 170°F, 23K ohm @ 87°F (within spec)
Swapped computer, no change
Swapped MAF, no change. Original MAF tested 3.7K ohms, .69 volt @ idle, approx 1.9 volt at high RPM
Installed new throttle position sensor
So where I am today:
I now think it's a fuel issue ......
Moved the PSI gauge to the windshield today and now that I see it under load, I think I've been going in the wrong direction this whole time looking at the ignition and control side of things. Even though I have a new fuel pump, new strainer, and new fuel filter, something is not right ....
About 1400 miles ago I had put in the new Carter brand OEM style pump because I had starting problems. That turned out to be an ignition switch problem. Everything was great for 600-1000 miles after that but then this WOT issue started up. So initially, trouble shooting the WOT thing, the pump just didn't make sense as the problem since it was new. Even testing it today, fuel pressure appears to be within specs at idle showing 31 PSI with vac line attached, 39 PSI w/o vac attached.
The problem is, that under load, the PSI drops to 10 PSI.
It's an electric pump so RPMs have no connection to flow like a block mounted pump might. Pressure is the resistance to flow. So low pressure means, not enough flow down the line (bad pump or plugged lines?), or, basically too big of a hole on the outlet side (bad PSI regulator allowing too much return to the tank???).
The pump (and strainer) only has about 1000 miles on it and the fuel filter is basically brand new. So flow wouldn't seem like it would be an issue. But then that's why I didn't bother checking the PSI under load in the first place, I assumed new means couldn't be a problem.
At this point I would have to guess the pressure regulator is leaking and creating a larger flow that the pump can keep up with when also flowing fuel to the injectors under load.
Does this sound like a PSI regulator issue??
So after reading all this, does my problem sound like it's the same as yours??
Anybody got any suggestions for us?
Looking for some diagnostic help on my ’95 GT 93,000 mile 5.0 motor with a stock intake system (except for K&N filter) and a Mac shorty / Flowmaster cat-back exhaust. In other words, a basically a stock original motor w/o many mods.
The car runs great except above 3000 RPM at wide open throttle. About 2000 miles ago I had some intermittent starting problems so the fuel pump, idle air control valve, ignition control module (not the computer), ignition coil, and fuel filter have all been replaced. (Replacing the ignition switch finally fixed the problem….). The car has been fine up to about a month ago.
For normal everyday driving the car is fine. If you run it up to 4500 at part throttle it’s fine and it will run continuously (cruise) at 4500 without a problem. It’s when you punch it and try to rev it above 3000 RPM that it has a problem. In other words, it will run up to 4500 fine with a part throttle but if it’s WOT (floored from a take off) it will run up to 3000-3500 RPM and then act like it’s running out of fuel above approximately 3000 RPM. It will start to die and loose power at 3000-3500 but momentum will carry it up to about 4500 (starts acting up about 3000 but will still rev up to 4500) but by then it’s dying enough to slow itself back down. If you hold it WOT it will continue to slow itself back down just like it’s running out of fuel. If you back off to part throttle at any point it’s fine and will run at 3000, 3500, 4000, what ever you want, but as soon as you step back down to WOT it acts like it’s loosing it’s fuel flow and begins to die again. I really don't believe it's a fuel issue though so the best way to describe it is to say it feels just like a rev limiter is kicking in or the advance is being pulled waaay too far forward or something. It's like it's a rev/vacuum controlled type issue.
No check engine light is showing and the fuel pressure regulator seems to be operating ok (I have a fuel pressure gauge mounted on the rail and at idle the PSI bumps up with the vacuum line disconnected like it should). With a new fuel pump and fuel filter, new ICA, and new ICM in the car and the regulator appearing to work I don’t really know where to go from here. It strikes me as a computer control/signal issue or some sensor like maybe the throttle position sensor type issue. I just hate to just throw money at new parts (particularly the computer) and hope something fixes it.
Anyone had this problem and know how to fix it!
About midyear I posted this:
Quick recap....
Replacement/check recap:
Car driven approx 2500 miles in the last 2 years, all replacements parts have less than 2000 miles on them. K&N filter, headers, Flowmaster cat-back are only intake/exhaust mods. No fault codes showing up on computer.
MSD 8MM Heli-Core wires, cap, and rotor replaced by previous owner. Have approx 8-10,000 miles on them with no apparent shorts. Have checked and cleaned cap, rotor,and distributor internals
When purchased car had intermittent starting issue so replaced:
New IAC - Idle Air Control Valve
New Ignition Coil
New ICM -Ignition Control Module
Added fuel gauge on rail, fuel pressure regulator increased PSI w/o vacuum but still decided to replace fuel pump. Everyone swore it was the fuel pump.
New Fuel Pump - standard flow Carter
New Fuel filter
New Ignition switch. Ignition switch fixed it!
Started having WOT throttle issue last summer
New Spark plugs (Motorcraft with factory .052 gap)
New Air filter - changed K&N out for stock Fram paper filter and cleaned MAF twice
Pulled distributor top apart, clean and no apparent loose/broken internals
TPS- Throttle position sensor checked ok, was .96 volt at idle to 4.69 at WOT
ACT - Air Charge Temp sensor is 60.1K ohm @ 49°F (within spec)
ECT - Engine Coolant Temp 4.67K ohm @ 170°F, 23K ohm @ 87°F (within spec)
Swapped computer, no change
Swapped MAF, no change. Original MAF tested 3.7K ohms, .69 volt @ idle, approx 1.9 volt at high RPM
Installed new throttle position sensor
So where I am today:
I now think it's a fuel issue ......
Moved the PSI gauge to the windshield today and now that I see it under load, I think I've been going in the wrong direction this whole time looking at the ignition and control side of things. Even though I have a new fuel pump, new strainer, and new fuel filter, something is not right ....
About 1400 miles ago I had put in the new Carter brand OEM style pump because I had starting problems. That turned out to be an ignition switch problem. Everything was great for 600-1000 miles after that but then this WOT issue started up. So initially, trouble shooting the WOT thing, the pump just didn't make sense as the problem since it was new. Even testing it today, fuel pressure appears to be within specs at idle showing 31 PSI with vac line attached, 39 PSI w/o vac attached.
The problem is, that under load, the PSI drops to 10 PSI.
It's an electric pump so RPMs have no connection to flow like a block mounted pump might. Pressure is the resistance to flow. So low pressure means, not enough flow down the line (bad pump or plugged lines?), or, basically too big of a hole on the outlet side (bad PSI regulator allowing too much return to the tank???).
The pump (and strainer) only has about 1000 miles on it and the fuel filter is basically brand new. So flow wouldn't seem like it would be an issue. But then that's why I didn't bother checking the PSI under load in the first place, I assumed new means couldn't be a problem.
At this point I would have to guess the pressure regulator is leaking and creating a larger flow that the pump can keep up with when also flowing fuel to the injectors under load.
Does this sound like a PSI regulator issue??
So after reading all this, does my problem sound like it's the same as yours??
Anybody got any suggestions for us?
TFI modules are the primary suspect on 86-93 Mustangs with high RPM power loss on a warm engine. If you have a TFI module that was replaced and still have the problem, how much thermal grease did you put on the back of the module? Did you throughly clean the old grease off the distributor?
jimdrechsler
Member
- Jun 29, 2006
- 248
- 1
- 18
what tool is used to get the tfi module off? what size are the screws? i just bought one today hoping to solve my power loss issue when hot. im going to change it and see what happens. also, can i access the screws without removing anything, or do i need to remove some hoses to access it.
thanks,
jim
thanks,
jim
Some of the TFI modules are removable with a thin walled 1/4" deep socket. Others have Torx fastners that require a special bit available at most auto parts stores.
See http://fordfuelinjection.com/?p=12 for more help
See http://fordfuelinjection.com/?p=12 for more help
Here was the solution to my problem. Had a thread running over at All Ford Mustang forums for a year on this. Finally solved it today..
Well I'm glad to announce that after almost an entire year of jackin' around with this thing I finally found the problem.
LESSON OF THE DAY: Don't assume that just because you've got a new part that there can't be anything wrong with it....
This solution to this is going to sound so simple ...... I found that my new fuel pump was defective!
I dropped the tank today, took the pump back to Pep Boys and swapped it for a new one (Carter brand standard OEM style).
It's running great!
Thanks for everyones suggestions over the past year!
My suggestion for those of you having a problem similar to mine, for a quick easy test, pull the schraeder valve out of the rail test port, clamp on a piece of 4-5ft hose, and attach a PSI gauge at the other end and then tape the PSI gauge to your windshield. The PSIs may look ok at idle, but you you need to test the pressure at WOT and see if that's the problem. (Remember this is only a temporary test set-up).
This is at least the third time now in my 30+ years playing on cars that I've been caught like this by defective new parts. Should know better by now, use common sense in trouble shooting and never assume new always means it actually works...
Wish I had done this months ago!!
Anyhow, good luck with yours!
Well I'm glad to announce that after almost an entire year of jackin' around with this thing I finally found the problem.
LESSON OF THE DAY: Don't assume that just because you've got a new part that there can't be anything wrong with it....
This solution to this is going to sound so simple ...... I found that my new fuel pump was defective!
I dropped the tank today, took the pump back to Pep Boys and swapped it for a new one (Carter brand standard OEM style).
It's running great!
Thanks for everyones suggestions over the past year!
My suggestion for those of you having a problem similar to mine, for a quick easy test, pull the schraeder valve out of the rail test port, clamp on a piece of 4-5ft hose, and attach a PSI gauge at the other end and then tape the PSI gauge to your windshield. The PSIs may look ok at idle, but you you need to test the pressure at WOT and see if that's the problem. (Remember this is only a temporary test set-up).
This is at least the third time now in my 30+ years playing on cars that I've been caught like this by defective new parts. Should know better by now, use common sense in trouble shooting and never assume new always means it actually works...
Wish I had done this months ago!!
Anyhow, good luck with yours!
Wow!!! I have a 2001 mustang GT and it started doing the same thing I know this is an old post but I love my GT and working on cars. I just took my intake malifold off and replaced the gaskets. It was a sucessful repair and my car is running like a champ. So of course I wanted to "get on her" and I noticed a power loss at around 3000 rpm. Thanks for the post Ill look into a fuel pump.
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