Engine hesitates and sluggish acceleration

Its common when one coil out the rest tent to follow here is are diagrams below of the job being done so you can fix yours with a guide that should help as well.


https://www.2carpros.com/articles/engine-misfires-or-runs-rough


Check out the diagrams (Below). Please let us know what happens.

How is it going? So my truck has recently started to idle really bad to where it might stall but does not. It also loses power when trying to accelerate. I have need to my local parts store and they suggested cleaning my throttle body and EGR valve and idle air control which I performed this weekend to no avail. Any thoughts?

Hello,

I would start with a tune up and then check the engine for vacuum leaks, here are a couple of guides that will shoe you how to get the problem fixed.

https://www.2carpros.com/articles/how-to-tune-up-a-car-engine

and

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

Please let us know what you find ;)

Cheers, Ken

I do not have any codes shown. All coils and packs are brand new. I have a cold air intake with a Spectre air filter. New fuel filter. My mechanic ran an inspection camera down the exhausts and did not find any restrictions. He said that the converters were actually gutted.

Truck runs good but as you go up any incline, I have to hit the accelerator or I will lose speed. When I hit the accelerator, I will get up to 3,000 rpm's until the climb is made then it goes back down to normal. It is like the motor should not be trying so hard. From stop to fast take off, it is all exhaust. No squealing tires or anything like that. It could use some faster improvement from 0 to 50. What are some things that can make this better? Is there an easy way to find exhaust leaks or a product that can indicate a leak? Thanks!

Exhaust leaks will cause low power a smoke machine or visual inspection should help with that but to me it sounds like you have low fuel pressure. Here is a guide to help us check the pressure:

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Fuel Pressure
Key on, engine off .................... 240-310 kPa (35-45 psi)
Engine running .................... 193-345 kPa (28-50 psi)

This guide can help as well

https://www.2carpros.com/articles/engine-has-low-power-output

Please run down this guide and report back.

Cheers, Ken

Every time I attempt to take off from a standstill I have no power to accelerate. Engine has no problems/trouble codes. Transmission has no issues, fluids have been changed, along with electrical issues that occurred due to a wiring issue. What could be the cause of no acceleration power at take off?

Hello,

This sounds like a classic plugged catalytic converter here is a guide to confirm the issue.

https://www.2carpros.com/articles/how-to-test-a-catalytic-converter

Please let us know what happens.

Cheers, Ken

I removed all cats, I have better throttle response now. But when actually taking for a drive it doesn't seem to want to shift gears.

I have seen where the MAF sensor can be a little off and cause low power and give false information to the PCM causing late shifts. Have you installed a new one recently? This sensor should be replaced as a regular maintenance item. When this sensor gets off a little it will not trigger a trouble code.

https://www.2carpros.com/articles/how-to-replace-a-mass-air-flow-sensor-maf

It also sound like a input shaft sensor can be causing problems as well but those will trigger a code when they go out.

I have a maf code and haven't changed it recently. but no codes for the input shaft

The MAF can cause the problem. That is what I would try next.

Yea, I just don't want to start throwing money at it though, bc the maf sensor for my truck is $100

Yep the sensor can be off a little which can be detected by a scanner that can read live data, and then compare that reading to a known good sensor. Some scanners have both live and average readings for a normal sensor. That is the only way to test you currant sensor that I know of.

when i accelerate the truck acts like its not getting enough fuel. it idles and revs fine in park and nuetral. takes a couple cranks to start(twice as much as normal). awhile ago i changed the fuel filter for the first time since ive owned it, bought it at 177k. the truck ran great right after i changed it. it ran like my dads new 4.6l ford. the next day the truck ran the same way it previously did(before the filter change). i proceeded to change the fuel tank, fuel pump, and fuel filter again. no change has occurred. the truck is still running bad. no idea what to do from here.

also the the mpgs are low about 7mpg

check the actual pressure. check the back pressure for the cat converters as well. Please go over these guides to help find the issue.

https://www.2carpros.com/articles/engine-has-low-power-output

and

https://www.2carpros.com/articles/how-to-test-a-catalytic-converter

Please run down these guides and report back.

roy

Thank you for your reply. I'm working on getting a fuel pressure gauge. How do i go about checking the back pressure for the cats? The exhaust is dual with separate mufflers. Both outlets seem to have a good steady pulse, when checked by hand.

you remove upstream o2 sensor and insert a fitting which measures the back pressure

Roy

when i accelerate it stays at the same speed and does not advance I changed the coil module thinking it was that but it wasn't. If its the fuel pump what do i do and how much would it cost? It shakes when i accelerate i don't know what it can be.?

You can change the pump yourself and save a bundle by removing the tank. check this link, our site made a great article about it.

https://www.2carpros.com/articles/how-to-replace-an-electric-fuel-pump

this is not the same car but gives you an idea :-)

OMG that was such good info! this site rocks :-)

That's what we do!

Truck has no power. When taking off . The more gas its given the weaker it gets till it reach high 2000.no Smell of raw gas no hiss from under hood took off cats no glog Good tune up. No smoke from exhaust. And always back fires from exhaust. When shifting gears till 4 and 5th gears are reached . Takes about 100 ft to get to 30to40mph.

Have you check the mass air flow sensor? If not get some mass air flow cleaner first and try cleaning it, if that don't work then unplug it and see if it runs any better. With it unplugged it won't have a great throttle response. Let me know what you find and we will go from there. Please go over these guides to help find the issue.

https://www.2carpros.com/articles/engine-has-low-power-output

and

https://www.2carpros.com/articles/how-to-test-a-catalytic-converter

Please run down these guides and report back.

I have cleaned, in the beginning of all this never unplugged. Not sure how much worse the throttle response can be. But thank you very much. I do appreciate you working with me.

Let me know how it does when you unplug the mass air flow ok.

It has rough idle motor shakes really bad and it won't go over 15 miles an hour. can't get out of there gear. I have replaced the MAP sensor the idle air control valve, plugs wires, injectors and cut out catalytic converters. still does same thing. please help

Let's start with checking for codes. Then we need to check for a vacuum leak as the intake manifolds have been known to leak on these engines.

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

Also, you said you replaced the MAP sensor but did you do anything with the MAF sensor?

Truck runs awesome when it is first started up, drives beautifully but the check engine light will come on for a second then go off and i lose all power. it lowers the idle to 500, chugs and if i try to give it gas it just pops through the intake system. it has a fresh tune up, new fuel pump and filter, and a new vacuum canister purge solenoid. nothing seems to fix it. i cannot get it to duplicate the problem in the driveway at idle it would rather strand me and have to be towed home.

Good morning,

Do you have the code? I need the code to help with the area of failure. Please go over these guides to help find the issue.

https://www.2carpros.com/articles/engine-has-low-power-output

and

https://www.2carpros.com/articles/how-to-test-a-catalytic-converter

and

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Please run down these guides and report back.

Roy

I have the reader for KOEO it is 565 Continuous code is 512 and KOER the codes are 538. 536. 632. The engine light is very intermittent, i just had it idling for an hour, power braked it to simulate being under power and nothing, stayed running great.

512 is the key. The KAM or keep alive memory looks like the issue. The ECM is bad.

NOTE
KOEO refers to Key On Engine Off (KOEO)
KOER refers to Key On Engine Running (KOER)
DTC refers to Diagnostic Trouble Code (DTC)
DTCs should be diagnosed in the order they are received.




DTC 511
Powertrain control module Read Only Memory test failure, KOEO self-test.

KOEO Hard Code - Replace Powertrain Control Module.

KOER Hard Code - Replace Powertrain Control Module.

KOEO Memory Code - Replace Powertrain Control Module.

DTC 512
Powertrain control module Keep Alive Memory test failure.

KOEO Memory Code .................... Go to QB1


DTC 513
Powertrain control module internal voltage failure, KOEO self-test.

KOEO Hard Code .................... QD1
See: Computers and Control Systems > Pinpoint Tests > QD1 - Diagnostic Trouble Code 513

KOER Hard Code .................... QD1
See: Computers and Control Systems > Pinpoint Tests > QD1 - Diagnostic Trouble Code 513

KOEO Memory Code .................... QD1
See: Computers and Control Systems > Pinpoint Tests > QD1 - Diagnostic Trouble Code 513

DTC 519
Power Steering Pressure switch circuit open during KOEO self-test.

KOEO Hard Code .................... Go to FF1


DTC 521
Power Steering Pressure switch circuit did not change states during KOER self-test.

KOER Hard Code .................... Go to FF5
See: Computers and Control Systems > Pinpoint Tests > FF5 - Verify Operator Interaction DTC 521

DTC 522
Vehicle not in "PARK" or "NEUTRAL" during KOEO or Park/Neutral switch circuit open.

KOEO Hard Code .................... Go to TD1
See: Computers and Control Systems > Pinpoint Tests > TD - Transmission Range Sensor

DTC 525
Indicates vehicle in gear or A/C "ON" during self-test.

KOEO Hard Code .................... Go to TA1
See: Computers and Control Systems > Pinpoint Tests > TA1 - System Identification

KOEO Memory Code .................... Go to TA1
See: Computers and Control Systems > Pinpoint Tests > TA1 - System Identification

DTC 527
Park/Neutral Position switch circuit open or A/C on KOEO self-test.

KOEO Hard Code .................... Go to TA1
See: Computers and Control Systems > Pinpoint Tests > TA1 - System Identification

DTC 528
Clutch Pedal Position switch circuit failure.

KOEO Memory Code .................... Go to TA1
See: Computers and Control Systems > Pinpoint Tests > TA1 - System Identification



DTC 536
Brake On/Off circuit failure or not actuated during KOER self-test.

KOER Hard Code .................... Go to FD1
See: Computers and Control Systems > Pinpoint Tests > FD1 - Verify Brake Was Pressed

KOEO Memory Code .................... Go to FD90
See: Computers and Control Systems > Pinpoint Tests > FD90 - Check For Proper Stoplamp Switch Installation

DTC 538
- Insufficient RPM change during KOER dynamic response test.
- Invalid cylinder balance test due to throttle movement during test.
- Invalid cylinder balance test due to cylinder identification circuit failure.

DTC 632
Transmission Control Switch circuit did not change states during KOER self-test.

KOER Hard Code .................... Go to TB2
See: Computers and Control Systems > Pinpoint Tests > TB2 - Diagnostic Trouble Codes 65, 632 and 653


DTC 565
Canister Purge circuit failure during KOEO self-test.

KOEO Hard Code .................... Go to KD6
See: Computers and Control Systems > Pinpoint Tests > KD6 - Check VPWR to CANP

I was afraid of that. now this one accesses from under the hood? Drivers side?

Yes it is. It is under hood, drivers side.

Roy

All other codes are gone. i went ahead and ordered a new mass air sensor and installed it worked great! thank you.

Will be driving along fine for about 20 miles, then the engine loses power like it is going to shut off. Pushing gas pedal to floor and it sputters. Some times it backfires. Engine light pops on then I switch to the reserve tank and the engine light goes off and the truck running and drives smooth. For some reason this only happens while using the main tank. Does this truck have a fuel pump driver module? If so could that be the problem?

There is no driver module on this truck. It sounds like the pump in the main tank has gone bad. When replacing the pump, inspect the tank for rust. The last one of these trucks that I worked on ate my lunch because I did not check for rust and I had to eventually remove the tank and send it to a local radiator shop so they could acid-dip it.

Thank you!!

No problem!

The truck starts fine. After driving anywhere from a quarter to a half-mile the truck slows down as if I took my foot off the gas pedal. I have to floor the gas pedal and let up, then it roars back to life, only to do it again over and over. Three different mechanics have tried everything they can think of that could go wrong under the hood. No one has checked anything pertaining to the gas tanks. It doesn't matter which tank, the problem persists. The truck doesn't have a computer to plug into to run diagnostics. Any help sure would be appreciated. Marsha

Hi,

My first suspect is fuel pressure or even a faulty catalytic converter. I have seen converter insides come loose and rattle around causing a blockage of exhaust from the engine. Do you notice any rattling?

Do me a favor. Although this doesn't have an OBD2 design for a scan tool, you can still retrieve diagnostic trouble codes. Here is a link that explains how to do it without using a scanner:

https://www.2carpros.com/articles/ford-lincoln-mercury-obd1-1995-and-earlier-diagnostic-trouble-code-definition-and-retrieval

Try that and let me know if anything is found. If not is, then I feel we should check fuel pressure.

Let me know.

Joe