Well, I've started my usual 60+ mile commute for school everyday and recently whenever I'm driving it feels like the engine just bogs down, then picks itself back up.

It will do it when going from a dead stop and accelerating, and when cruising on the highway.

Recently I replaced the TPS due to bad idle and dropping RPM's quickly, which fixed that problem, now I have this.


I'm thinking the fuel pump is starting to give out...any ideas?

It's a '94 GSR in a '94 Civic DX btw.

 

did you set the TPS correctly?
how old is the O2?

 

did you notice this new problem right after you replaced the tps?

when's the last time you replaced your plugs/wires/cap/rotor? do you notice it in the rain or when its really humid out?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by na+b18c_hatch &raquo;</TD></TR><TR><TD CLASS="quote">did you notice this new problem right after you replaced the tps?

when's the last time you replaced your plugs/wires/cap/rotor? do you notice it in the rain or when its really humid out? </TD></TR></TABLE>


It was doing it SOME prior to replacing the TPS, but has gotten worse and worse.

I did the swap back in November of '06 which everything was replaced with OEM-quality parts...so about 2 years and 30K miles of driving.

And I live in Southeast Texas...it's humid everyday and rains just about every week (especially with hurricane season in full swing).

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Relic1 &raquo;</TD></TR><TR><TD CLASS="quote">did you set the TPS correctly?
how old is the O2?</TD></TR></TABLE>

Yep, TPS was calibrated correctly. As for the O2 sensor, it was replaced the same time as the swap (2 years, 30K miles).

It hasn't throw any codes for anything (yet), but from what I can tell it doesn't throw a code until it's on its last leg.

EDIT: 1500 posts

 

I know it's tough to describe problems like this, and OBD1 stuff can be a bit hard to diagnose without a CEL.

My .02 is that I have had a couple OBD1 Civics give me a similar issue, one was a faulty 02 sensor, the other was a leaking header.

An uncalibrated/not properly TPS is also suspect.

No offense, I hope this helps.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mcvtec &raquo;</TD></TR><TR><TD CLASS="quote">
I know it's tough to describe problems like this, and OBD1 stuff can be a bit hard to diagnose without a CEL.
My .02 is that I have had a couple OBD1 Civics give me a similar issue, one was a faulty 02 sensor, the other was a leaking header.

An uncalibrated/not properly TPS is also suspect.

No offense, I hope this helps.

</TD></TR></TABLE>

I'm not cancelling out the possibility of it being the TPS, but I had my dad who has owned/operated his own import repair shop for over 25 years check it all over...people make mistakes, but I don't think that's it right now.

It's really hard to describe the issue...I'll be cruising at 40mph in 5th gear and it feels like the car just shuts off (without actually dying)...or takes a plunge in fuel pressure/fuel itself.

Would the O2 sensor throw the air/fuel ratio off that much to make the car feel like it's going to die then pop back on?

 

Bump for some more input.

 

After cruising sometimes I get gunk on my 02 sensor, and at very light throttle the car surges a bit, but running through VTEC usually solves the problem for me.

Sounds like your 02 sensor is a possible culprit.

 

I'd try removing and cleaning the throttle body before doing anything else. I've seen problems similar to this several different times that were solved by doing that. In my personal case, it seemed that the butterfly was sticking shut at very light throttle, causing the car to bog and buck badly.

I also had the same problem on a b18 that turned out to be because I'd gotten some water in 2 of the plugwells. This was also causing the car to buck and stutter. I pulled the plugs, dried everything out, and put in new plugs, and it runs like a champ.

 

^I cleaned the throttle body and the spots that I could reach in the intake manifold, so I'm sure that's not it.


I need to put a fuel pressure gauge on it and that will answer my question of it, but I've been busy with school/work/approaching hurricanes...

 

had pretty much the same exact problem. take the dizzy cap off and check your cap and rotor button. on the 92-95 the screw comes out pretty easily for some reason, so your rotor button will pop off, and just kind of spin with the rotor, not really making contact and therefore your plugs won't all fire. Check that, it'll tkae you 5 minutes.

 

^I'll give it a look tomorrow


No school tomorrow due to Ike...good, but bad. Wish Texas luck guys.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by OMGWTFBBQ! &raquo;</TD></TR><TR><TD CLASS="quote">After cruising sometimes I get gunk on my 02 sensor, and at very light throttle the car surges a bit, but running through VTEC usually solves the problem for me.

Sounds like your 02 sensor is a possible culprit. </TD></TR></TABLE>

wouldn't the O2 sensor give a CEL code? i am having the same exact problem right now, car is actually at the shop right now. they still cant figure it out. i live in hawaii, so the humidity/rain seems to be a common factor.

 

I put a fuel pressure gauge on it last week, and everything was within specs...it rained today leaving school and it seemed to be doing it worse than usual.

I took a video of it today while driving, so I'll have to put that up so that you can see what I'm talking about.


But...mainly...

When moving from a dead stop I will go to accelerate and it will completely lose power (almost like I'm not giving it any gas), and I will give it more gas and it picks back up...sometimes it takes a second even after I give it the throttle.

Other times I will be cruising on the highway (70-80mph) and it will just cut in and out, almost like a bucking horse I guess. It will lose power, gain power, lose power, gain power...and EVENTUALLY it clears out, but sometimes it takes longer.

 

Bump