Throttle issue with pickup truck.

[Zero Knievel]

On my Mazda B3000, there’s an issue with the accelerator that I’d like to fix but can’t identify the cause.  Sometimes, when trying to use the accelerator pedal, there’s this resistance like the pedal doesn’t want to move.  You apply more pressure, and it gives, but then you’re getting a lot more gas than you wanted.  This only happens (from what I recall) when my foot is off the pedal, but it doesn’t happen every time.  I don’t see any evidence of the cable being damaged or binding.  On the pedal side, the cable connects to the top of the pedal which has a spring spacer.  If I pull on the cable, there’s about an inch of excess cable.  I don’t know if that’s normal.  At the throttle control under the hood, it seems fine.

 

Thoughts?

[DaveK]

I know nothing about this stuff but it anything lubed down there? 

[Zero Knievel]

2 hours ago, DaveK said:

I know nothing about this stuff but it anything lubed down there? 

No.  The cable shows no indication of binding, and the mechanical bit under the hood works effortlessly.

[ironmike]

Hmm, found this . . . may or may not apply.

 

https://www.therangerstation.com/forums/threads/replacement-throttle-body-cable-options-for-1994-vintage-mazda-b3000.174443/

Edited August 2 by ironmike

[SwampNut]

This is the clear and obvious solution.  https://a.co/d/17BgTbZ

[tomek]

3 hours ago, Zero Knievel said:

No.  The cable shows no indication of binding, and the mechanical bit under the hood works effortlessly.

Disconnect cable from throttle body, and check if butterflies open smoothly. Do same for gas pedal. I mean it has to be one of those three, there is nothing else there, so,,,,

[Zero Knievel]

7 hours ago, SwampNut said:

This is the clear and obvious solution.  https://a.co/d/17BgTbZ

Smart ass…. 😘

[superhawk996]

Carbon/oil/junk buildup in the throttle body.  Take the air tube off, hold the throttle open, and use a rag wet with carb cleaner to clean it up.  No need to make it pretty, just clean off the excessive goo.

[Zero Knievel]

Engine is direct injection.  There should be no buildup issues at the throttle control.

[The Krypt Keeper]

1 hour ago, Zero Knievel said:

Engine is direct injection.  There should be no buildup issues at the throttle control.

But, there is a large volume of airflow that is slightly filtered down but dust particle size varies and can build up over time in the throttle body. Say in an antique Mazda pickup this is roughly 30yrs old.. If anything as you say "there should be no buildup issues" well I guess checking and eliminating that as the issue should take almost as long as it took me to type this up. 

 

You don't have your floor mat crumpled up behind the pedal do you? 

 

I am going with cable bind but really leaning to the pedal assembly. Those two are used constantly while driving and the assembly is in dirty area from rain, snow, dirt and so on from shoes. Its older, made of plastic mostly and has a service lifespan 

[blackhawkxx]

1 hour ago, Zero Knievel said:

Engine is direct injection.  There should be no buildup issues at the throttle control.

Are you sure about that?

 

The 1998 Mazda B3000 does not have direct injection. It is equipped with a 3.0L V6 engine (VIN U, 6-cylinder, 12-valve), which uses multi-port fuel injection (MPFI). Direct injection, where fuel is injected directly into the combustion chamber, was not used in this engine. Instead, the MPFI system injects fuel into the intake manifold before it enters the combustion chamber.

[SwampNut]

I was sitting back, making bags and bags of popcorn, waiting for the moment that the actual mechanic here would be foolish enough to provide an answer and then be told he was wrong.  Backing up what was already posted above...

 

 

[Zero Knievel]

Okay.  I cleaned the butterfly valve and surrounding area with carb/choke cleaner.  Got a nice bit of brown and black stuff out with my fingers and paper towels soaked with the cleaner.  About halfway, I see a label on an associated part saying not to use cleaners on the valve as it has a protective coating.  Well, too late for that, and after 30 years, what are the odds it’s still there?

 

Tried to address the 1/4 inch slack in the cable.  What I noticed is that the cruise control has its own control arm.  So, without my foot on the pedal with the cruise control on, the slack is at the throttle body.  This arches the slack enough that it can catch on a tab on the mechanism.  I used a small zip tie to make a band to keep the cable in its channel.  I doubt that’s the issue as I would expect it to produce acceleration then a sudden drop once the cable slips off and goes back into the channel.

 

Have yet to take it for a test drive.  As far as it being dirty being the cause, I can see it being possible.  If I let it close completely and gently pressed on the mechanism, sometimes it released easier than others.

[Zero Knievel]

Just did the test drive.  No issues so far.  I’ll know if it reappears over the next couple of weeks.

 

Thanks, everyone.

 

FWIW, how does “multi port fuel injection” NOT make one think it means direct port injection.  How is it different from throttle body injection…or are the fuel injectors in the individual pipes of the intake manifold and not in the cyclinder head itself?

[SwampNut]

In the Bad Old Days, I would spend a few minutes typing, or a few minutes googling to post a link, but now, it's a five second job.

 

Answer the question in the last post here

 

 

 

 

Answer the question in the last post here

 

 

 

Absolutely! Here’s a clear answer to the question in the last post:

Q:
How does “multi port fuel injection” NOT make one think it means direct port injection? How is it different from throttle body injection… or are the fuel injectors in the individual pipes of the intake manifold and not in the cylinder head itself?

A:
Great questions! Here’s the breakdown:

• Multi-Port Fuel Injection (MPFI):
  In MPFI, each cylinder gets its own fuel injector. These injectors spray fuel into the individual intake runners—not directly into the combustion chamber, but into the intake manifold just upstream of where the air enters the cylinder. This means the fuel mixes with air before entering the cylinder itself.

• Direct Injection (DI):
  In direct injection systems, the injectors spray fuel directly into the combustion chamber of each cylinder. This allows for more precise fuel delivery and typically improves efficiency and power, but it’s a newer (and more complex) technology.

• Throttle Body Injection (TBI):
  In TBI, there is usually just one or two injectors located at the throttle body (where the carburetor would have been on older engines). They spray fuel into the incoming air stream at the entry to the intake manifold, and then the mixture gets divided up and sent to each cylinder, much like with a carburetor.

[Zero Knievel]

AI is already making you lazy. 😛 

[SwampNut]

[CALCXX]

Mike has been using his own version of AI for years.

Everytime he types in a question, the answer is ---

 

That won't work.

 

Download the app today.  ZI

Edited August 4 by CALCXX

[CALCXX]

On 8/3/2025 at 9:17 AM, Zero Knievel said:

 I used a small zip tie to make a band to keep the cable in its channel.  I doubt that’s the issue as I would expect it to produce acceleration then a sudden drop once the cable slips off and goes back into the channel.

 

 

Why didn't Mazda think of that?

[Zero Knievel]

2 hours ago, CALCXX said:

Why didn't Mazda think of that?

 

It would make it impossible to attach/remove the throttle cable.  I can always cut the zip tie.

[XXitanium]

9 hours ago, CALCXX said:

Mike has been using his own version of AI for years.

...are you calling us a fake?

[superhawk996]

On 8/3/2025 at 1:36 AM, Zero Knievel said:

Engine is direct injection.  There should be no buildup issues at the throttle control.

 

On 8/3/2025 at 9:17 AM, Zero Knievel said:

Okay.  I cleaned the butterfly valve and surrounding area with carb/choke cleaner.  Got a nice bit of brown and black stuff out with my fingers and paper towels soaked with the cleaner.  About halfway, I see a label on an associated part saying not to use cleaners on the valve as it has a protective coating.  Well, too late for that, and after 30 years, what are the odds it’s still there?

 

Tried to address the 1/4 inch slack in the cable.  What I noticed is that the cruise control has its own control arm.  So, without my foot on the pedal with the cruise control on, the slack is at the throttle body.  This arches the slack enough that it can catch on a tab on the mechanism.  I used a small zip tie to make a band to keep the cable in its channel.  I doubt that’s the issue as I would expect it to produce acceleration then a sudden drop once the cable slips off and goes back into the channel.

 

Have yet to take it for a test drive.  As far as it being dirty being the cause, I can see it being possible.  If I let it close completely and gently pressed on the mechanism, sometimes it released easier than others.

Take it to mechanic, or a junkyard, or just park it; you're too stupid to work on it.

[superhawk996]

13 hours ago, CALCXX said:

 

Why didn't Mazda think of that?

Maybe because Mike wasn't on their engineering team.  Or maybe because their engineering team understood that the cables act differently when you press the pedal vs. manually open the throttle valve at the throttle body.

 

One of my friends told me that there's no such thing as a dumb 50 year old because they'd already be dead, I disagree.

[DaveK]

52 minutes ago, superhawk996 said:

 

Take it to mechanic, or a junkyard, or just park it; you're too stupid to work on it.

Quote of the….well, lifetime. 

[DaveK]

47 minutes ago, superhawk996 said:

Maybe because Mike wasn't on their engineering team.  Or maybe because their engineering team understood that the cables act differently when you press the pedal vs. manually open the throttle valve at the throttle body.

 

One of my friends told me that there's no such thing as a dumb 50 year old because they'd already be dead, I disagree.

Oh fuck you, you fucking fuck. You aren’t allowed 2 of the forums best quotes ever in the same evening. 
 

IT’S NOT ALLOWED. 🚫