When I try to do a rapid acceleration the needle gets to 4000RPM and then starts falling gradually despite still having my foot on the accelerator. To get it to rise again I would have lift my foot of the gas and apply it again gently.
This does not happen when I accelerate slowly, if I
do slowly, I would hit 5000RPM without any
problems.
The Check Engine light is not on and I have used a dealer level diagnostic tool on the car and it returns no codes whatsoever.
Outside this the car moves fine and does not even
jerk when this happens, you just notice the car
slowing down despite hitting the accelerator. Any ideas?

The car is a 2003 4cyl Accord.

Only way this can happen without a CEL is if it's an issue along your fuel lines i.e fuel pump all the way to the injectors and FPR.
When you turn on your ignition without starting the car does your check engine light come on?

nissparts: Only way this can happen without a CEL is if it's an issue along your fuel lines i.e fuel pump all the way to the injectors and FPR.
When you turn on your ignition without starting the car does your check engine light come on?

Yes it comes on momentarily and goes off once I start the car

I may have found what the problem is; I did a drain and refill of ATF 3wks ago.

I just checked my ATF level immediately after coming back from work today and found it to be at the low mark. I inspected the drain bolt and there was no leakage.

I have refilled up to the high mark and would do a test drive tomorrow. will update after the test drive.

No luck yet. No change after my test drive...Ikenna and Siena

thast a sign of transmission problem..hope u refilled with original honda atf?...also revving ur car to 5000rpm isnt very good for ur engine!

cretin: thast a sign of transmission problem..hope u refilled with original honda atf?...also revving ur car to 5000rpm isnt very good for ur engine!

I used original Honda atf which I bought from jand to be precise. still troubleshooting will let us know when I get I cure. I also welcome more comments

cretin: thast a sign of transmission problem..hope u refilled with original honda atf?...also revving ur car to 5000rpm isnt very good for ur engine!

I used original Honda atf which I bought from jand to be precise. still troubleshooting will let us know when I get a cure. I also welcome more comments

Piyke: When I try to do a rapid acceleration the needle gets to 4000RPM and then starts falling gradually despite still having my foot on the accelerator. To get it to rise again I would have lift my foot of the gas and apply it again gently.
This does not happen when I accelerate slowly, if I
do slowly, I would hit 5000RPM without any
problems.
The Check Engine light is not on and I have used a dealer level diagnostic tool on the car and it returns no codes whatsoever.
Outside this the car moves fine and does not even
jerk when this happens, you just notice the car
slowing down despite hitting the accelerator. Any ideas?





The car is a 2003 4cyl Accord.

is your car automatic or manual ?

remember with a manual you need to change to lower gear to accelerate fast

automatics have what we call kickdown sensor, when acceleratiom peddle is down on the flow the car changes down to lower gear for you to have a good accelaration

lonelydora: It's not a tranny problem, Most modern cars have what i called Circuit breakers( i have forgotten the actual name), if you accelerate at once it will break somehow because the cylinder is getting too much fuel than it can burn..... when you remove your leg from the acclerator, it will pick up again. i will give the explanation later on.

I do believe you that this is not a transmission problem because:
1. [b]The car changes gears effortlessly as you can tell the change of gears in automatics by the..."change in gear sound" . Also none of the gears are stiff or hard to engage. All gear changes on the gear stick are supple.

2. I have used a diagnostic tool which has the capability to scan transmissions apart from just the powertrain and it returned no codes as I earlier stated.

My mechanic said something about cleaning the engine sensor (I'm not sure this is the mechanical name), but I'm still doing my own research before I take that advice. So far an auto engineer has suggested that clogged catalytic converters could cause this. I would pursue this lead and see what happens.

First things first, I intend to service my injectors. Not because I'm convinced its the cause, but what the heck, it won't hurt.

Thanks to everyone who has given their sweat here. I promise I would update once its solved.

ZIM DRILL:

is your car automatic or manual ?

remember with a manual you need to change to lower gear to accelerate fast

automatics have what we call kickdown sensor, when acceleratiom peddle is down on the flow the car changes down to lower gear for you to have a good accelaration

Its auto

The other thing I should state is that this problem started just after I bought fuel from an Oando filling station and added ABRO Injector cleaner.

Piyke: The other thing I should state is that this problem started just after I bought fuel from an Oando filling station and added ABRO Injector cleaner.

I have talked about people putting in any container they see written Injector cleaner in their fuel tanks. As far as am concerned, that ABRO injector cleaner is a no-go area. Most of the ABRO products you see in Nigeria are concotted here. Some of their coolants are simply water with poster colour.

Probably, your car is having sticky intake valve issue or partially clogged injectors issue, as a result of the bad injector cleaner you introduced in the fuel system.

Techron injector clearner would have been the best solution here, but you wont find it in Nigeria. Notwithstanding, we have TOTAL & Mobil injector cleaners which you can get in any Total and Mobil filling stations. The Total cost N500, while Mobil cost N750. Try any of them and see if any improvement. But you wont notice the change immediately. It may take it a day or so to thoroughly clean up the clogged system, if they are as good as they claimed.

I hope it hasnt affected the fuel pump as well? Fuel pressure guage could tell us how good your fuel pump still is.

By the way, your car issue has nothing to do with the transmission. At least, your ECU is not going into Limp home mode.

Thats all i can think of right now. Will let you know more if any other ideas popped up. Goodluck.

Ikenna.

Ikenna351:

I have talked about people putting in any container they see written Injector cleaner in their fuel tanks. As far as am concerned, that ABRO injector cleaner is a no-go area. Most of the ABRO products you see in Nigeria are concotted here. Some of their coolants are simply water with poster colour.

Probably, your car is having sticky intake valve issue or partially clogged injectors issue, as a result of the bad injector cleaner you introduced in the fuel system.

Techron injector clearner would have been the best solution here, but you wont find it in Nigeria. Notwithstanding, we have TOTAL & Mobil injector cleaners which you can get in any Total and Mobil filling stations. The Total cost N500, while Mobil cost N750. Try any of them and see if any improvement. But you wont notice the change immediately. It may take it a day or so to thoroughly clean up the clogged system, if they are as good as they claimed.

I hope it hasnt affected the fuel pump as well? Fuel pressure guage could tell us how good your fuel pump still is.

By the way, your car issue has nothing to do with the transmission. At least, your ECU is not going into Limp home mode.

Thats all i can think of right now. Will let you know more if any other ideas popped up. Goodluck.

Ikenna.

Thanks a lot Ikenna, I owe you one. Will search for total or Mobil ASAP. I normally use STP which I buy from Shoprite but they've not had it for a while. I'll stay clear of Injector cleaners after now. I'll keep you posted. Thanks a bunch.

Siena: Not every MAF issue triggers a CEL. Even if it's still within spec, it could still be faulty. Remember, voltage rises and falls with airflow.

You need to get it tested. A diagnostic tool with measuring block capability. May need to be a dedicated Honda OBD platform. Voltage tests can also be carried out with a digital multimeter. Do you know what make it is? If it's a BOSCH MAF, I can tell you how to test it.

Most Japmobile's run DENSO, Hitachi, Mitsubishi etc MAF's though, and I'm not conversant with the pin-outs on these.

Thanks a lot Siena, This accord trim doesn't have a MAF sensor rather it just has an IAT

Today I added Mobil Injector cleaner as suggested by Ikenna. Would drive it for some days before attempting another test, this should provide enough time to clean any clogging in the fuel system. I've also used this opportunity to clean the fuel filter. Fingers crossed...

Piyke:

Thanks a lot Siena, This accord trim doesn't have a MAF sensor rather it just has an IAT

Some MAFs have IAT inside them. Since yours have separate IAT, I would suspect it has MAP instead, since you are saying yours doesnt have MAF, and I doubt if it has AFM.

So, I wouldnt rule out AFM, MAF or MAP yet, since they could give similar symptom when they fail too.

But it got me thinking. If your injectors are clogged, you should be experiencing hesitation, misfiring or rough idling. Hmm! But then, you said the problems started after introducing bad fluid in the fuel system and combustion chambers. That shouldnt affect MAP then. Anyway, if there is no improvement by tomorrow or next, then do as Siena suggested. Look for the MAP and swap in another and see if any improvement. If yours is the type that can be cleaned, do so and put it back and check for result. If its MAF, unplugging it will make the car run better, if the MAF is faulty. Am not sure about MAP, but you can try that.

By the way, have you checked to be sure you dont have any vacuum leak?

Ikenna.

If the injector clean doesnt work, then you may have a loose hose causing a vacuum leak as Ikenna mentioned. Check the hose on your airbox if it's loose

Siena: Not every MAF issue triggers a CEL. Even if it's still within spec, it could still be faulty. Remember, voltage rises and falls with airflow.

You need to get it tested. A diagnostic tool with measuring block capability. May need to be a dedicated Honda OBD platform. Voltage tests can also be carried out with a digital multimeter. Do you know what make it is? If it's a BOSCH MAF, I can tell you how to test it.

Most Japmobile's run DENSO, Hitachi, Mitsubishi etc MAF's though, and I'm not conversant with the pin-outs on these.

Ikenna351:


Some MAFs have IAT inside them. Since yours have separate IAT, I would suspect it has MAP instead, since you are saying yours doesnt have MAF, and I doubt if it has AFM.

So, I wouldnt rule out AFM, MAF or MAP yet, since they could give similar symptom when they fail too.

But it got me thinking. If your injectors are clogged, you should be experiencing hesitation, misfiring or rough idling. Hmm! But then, you said the problems started after introducing bad fluid in the fuel system and combustion chambers. That shouldnt affect MAP then. Anyway, if there is no improvement by tomorrow or next, then do as Siena suggested. Look for the MAP and swap in another and see if any improvement. If yours is the type that can be cleaned, do so and put it back and check for result. If its MAF, unplugging it will make the car run better, if the MAF is faulty. Am not sure about MAP, but you can try that.

By the way, have you checked to be sure you dont have any vacuum leak?

Ikenna.

Thanks again guys. It has a MAP just as Ikenna suggested. wasn't able to do a test drive today, it rained massively today so no speeding.

Siena its a Denso MAP, once I do a test drive that isn't successful I'll proceed to troubleshoot the MAP as suggested.

In also forgot to mention that I read Livedata from the car, before I added the injector cleaner, I focused on fuel trims STFT never showed the car was running lean even at high RPMs so that tells me the fuel pump is still good. It never ran rich too. fuel trims typically lay within +-5%

Never mind. Just seen that you checked at different RPMs

I did a test drive yesterday with no change. So I'll proceed to troubleshoot the MAP sensor as recommended by Siena. I've inspected the intake hose and made sure everything is fitted tight.

Should be at Enugu by the weekend to see if I'll pick up a new MAP sensor at coal camp. I've also read that a malfunctioning VSS can cause similar symptoms. will explore that route too.

Still need your assistance with any info you feel will be beneficial...

Piyke: I did a test drive yesterday with no change. So I'll proceed to troubleshoot the MAP sensor as recommended by Siena. I've inspected the intake hose and made sure everything is fitted tight.

Should be at Enugu by the weekend to see if I'll pick up a new MAP sensor at coal camp. I've also read that a malfunctioning VSS can cause similar symptoms. will explore that route too.

Still need your assistance with any info you feel will be beneficial...

Replacing parts at random is not always ideal, because you could get more frustrated when you dont get results as you replace parts. Lol! Trust me, it can be very frustrating.

Back then, before i got my 505 v6 Electrical workshop manual, comprising of wiring schematics and sensor values of the car, i would take the car to APO, asked them to bring used parts of the sensors or components i want to test or change. I would swamp them in, like 4 or 5 of them. If i see any improvement, i would ask for the amount. If they say 5k, i would price it N700., knowing that they wouldnt sell to me at that price. I would them leave them and seek for a new one (if thats what i intend to buy anyway). My point is, i was using used parts to confirm if my sensor or component is still ok or the faulty. Nice tip! Lol! But when i got the manual, i now check the values with my DMM. If the DMM read below factory value (resistance, volts or both), i would know the parts would need to be changed.

In your case, even if you apply my old method of diagnosis, it maynot work since you will need to drive the car to know if there will be any change or not. Hmm! Which way now?

If i may ask, where your MAF positioned? Is it mounted directly on the intake manifold or mounted elsewhere, but connected to intake manifold via a vacuum line?

Am asking the above question because, if its mounted directly on the intake manifold, you can pull it out, clean it and put it back. Some people have claimed they cleaned theirs with Carb cleaner and it started working again. But some will argue that carb cleaner will be too harsh for the MAP, since its made of plastics. Here is proper fluid for cleaning MAP, the MAF or throttle body cleaner, but where will you see them in Nigeria? But you never know, you may find such in Shoprite. At least, i was surprised to see WD-40, meant for cleaning electrical connectors or contacts, etc. I saw it at Enugu Shopite last Xmas, 30/12/2012. You can try shoprite first.

Then if the MAP is not mounted on the intake, check the condition of the vacuum line, right from the MAP sensor to the intake. If any leak or crack is detected,replace it. If there is carbon build up inside the hose, clean it out and put it back. It may put life back into the non-functioning MAP sensor.

The speed sensor in Peugeots controls only the speedomter, variable ratio steering and ABS in some models. Unless Asian cars have Vehicle speed sensor and also speed sensor separately, i wouldnt know.

I will be in Enugu too this weekend, but i dont know if i will have enough time to go round the town.

Ikenna

Ikenna351:

Replacing parts at random is not always ideal, because you could get more frustrated when you dont get results as you replace parts. Lol! Trust me, it can be very frustrating.

Back then, before i got my 505 v6 Electrical workshop manual, comprising of wiring schematics and sensor values of the car, i would take the car to APO, asked them to bring used parts of the sensors or components i want to test or change. I would swamp them in, like 4 or 5 of them. If i see any improvement, i would ask for the amount. If they say 5k, i would price it N700., knowing that they wouldnt sell to me at that price. I would them leave them and seek for a new one (if thats what i intend to buy anyway). My point is, i was using used parts to confirm if my sensor or component is still ok or the faulty. Nice tip! Lol! But when i got the manual, i now check the values with my DMM. If the DMM read below factory value (resistance, volts or both), i would know the parts would need to be changed.

In your case, even if you apply my old method of diagnosis, it maynot work since you will need to drive the car to know if there will be any change or not. Hmm! Which way now?

If i may ask, where your MAF positioned? Is it mounted directly on the intake manifold or mounted elsewhere, but connected to intake manifold via a vacuum line?

Am asking the above question because, if its mounted directly on the intake manifold, you can pull it out, clean it and put it back. Some people have claimed they cleaned theirs with Carb cleaner and it started working again. But some will argue that carb cleaner will be too harsh for the MAP, since its made of plastics. Here is proper fluid for cleaning MAP, the MAF or throttle body cleaner, but where will you see them in Nigeria? But you never know, you may find such in Shoprite. At least, i was surprised to see WD-40, meant for cleaning electrical connectors or contacts, etc. I saw it at Enugu Shopite last Xmas, 30/12/2012. You can try shoprite first.

Then if the MAP is not mounted on the intake, check the condition of the vacuum line, right from the MAP sensor to the intake. If any leak or crack is detected,replace it. If there is carbon build up inside the hose, clean it out and put it back. It may put life back into the non-functioning MAP sensor.

The speed sensor in Peugeots controls only the speedomter, variable ratio steering and ABS in some models. Unless Asian cars have Vehicle speed sensor and also speed sensor separately, i wouldnt know.

I will be in Enugu too this weekend, but i dont know if i will have enough time to go round the town.

Ikenna

Thanks a lot for the advice Ikenna, my MAP is just beside the throttle body. Never knew shoprite would have fluid for cleaning electrical components. Infact it was because I know carb cleaner isn't good for electrical components like MAF that made me think of replacing it.

Well, once I come into Enugu I'll hola you. One thing I like about this challenge is that I havent given the car to any mechanic tear apart. I'm learning.

Piyke:

Thanks a lot for the advice Ikenna, my MAP is just beside the throttle body. Never knew shoprite would have fluid for cleaning electrical components. Infact it was because I know carb cleaner isn't good for electrical components like MAF that made me think of replacing it.

Well, once I come into Enugu I'll hola you. One thing I like about this challenge is that I havent given the car to any mechanic tear apart. I'm learning.

I arrived Enugu this afternoon, drove to Shoprite and found the WD-40 out of stock. Well, will try the Abuja Shoprite when i get back.

Ikenna.

Ikenna351:

I arrived Enugu this afternoon, drove to Shoprite and found the WD-40 out of stock. Well, will try the Abuja Shoprite when i get back.

Ikenna.

Thanks for the headsup, leaving Owerri in the next 20 mins. I'll check to see if game has in their auto section. Will buzz you soon.

Ikenna just confirmed the absence of WD-40 at shoprite. heading to game...

I'm sorry I'm lost.
What do you want to do with WD-40?
I hope it's not for cleaning the MAP/MAF sensor?

REALLY!..WHAT DO U WANT TO do with wd -40?.
if u r in ph go to ikoku..its there..or parkshop ph/lenu shopping mall abacha rd...
but pls o...dont use wd 40 inplace of maf cleaner.

WD-40 is a penetrating oil, you might need electrical contact cleaner like a crc maf cleaner 05110