I've been dealing with this problem for a while now, and can't seem to find the answer. Under ligh acceleration (20-40% throttle) the car hesitates and sometimes stops acceleration all together for a few seconds, and then jumps back to normal. I've replaced evertthing I though it could be and nothing has changed.

So far I've:

-Had the car timed
-All valves adjusted
-Replaced distributor
-Replaced cap & rotor
-Replaced Spark plugs
-Replaced Plug wires

The motor is a B20vtec motor in a Del Sol. Any Suggestions? I'm running out of ideas here...

 

what fuel management? Tuned? Was tuning done on street or load capable dyno or only full throttle??

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Evs-One &raquo;</TD></TR><TR><TD CLASS="quote">what fuel management? Tuned? Was tuning done on street or load capable dyno or only full throttle??</TD></TR></TABLE>

None thus far. I was told I was going to need a bigger fuel pump and a fuel pressure reg, but I didn't think that these things would have this big of an effect on the car. I believe I'm running in the ballpark of 35-40 psi on a ghetto crushed stock fpr, and the recomended amount is something like 45psi.

I have a safc, but don't know how to tune it. My tuner however does know how, and I believe he would give me a decent street tune if I asked. or idea?

 

tuning is a must....what ecu are you running right now?? I'm guessing a p28 maybe??

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 93eg2james &raquo;</TD></TR><TR><TD CLASS="quote">

None thus far. I was told I was going to need a bigger fuel pump and a fuel pressure reg, but I didn't think that these things would have this big of an effect on the car. I believe I'm running in the ballpark of 35-40 psi on a ghetto crushed stock fpr, and the recomended amount is something like 45psi.

I have a safc, but don't know how to tune it. My tuner however does know how, and I believe he would give me a decent street tune if I asked. or idea?</TD></TR></TABLE>

That's what I'd say, ur going from a 1.5 non-VTEC to a 2.0 vtec. Fuel pump might be of insufficient size and/or going do to stress levels. Also, if those #'s u stated are correct it's obviously dumping too fast.

Those are the two things I'd look at before anything else.

 

No no, I have a p72 gsr ecy all hooked up and working nicely.

So it's possible for the fuel delivery to be the problem? I would have guessed it would be running lean, but not so lean that it hesitates like that. Am I in risk of detonation?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 93eg2james &raquo;</TD></TR><TR><TD CLASS="quote">No no, I have a p72 gsr ecy all hooked up and working nicely.

So it's possible for the fuel delivery to be the problem? I would have guessed it would be running lean, but not so lean that it hesitates like that. Am I in risk of detonation?</TD></TR></TABLE>

No. I would definitely look into getting it replaced ASAP though and not go too hard on it. See running an engine lean like that increases the chance that you'll throw a rod. So I'd just be careful w/ the RPM until you make sure you're pushing adequate fuel pressure w/ the correct FPR.

 

think tuning might be your problem. try throwing a wideband on it when its bogging to see what it does.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Syndacate &raquo;</TD></TR><TR><TD CLASS="quote">No. I would definitely look into getting it replaced ASAP though and not go too hard on it. See running an engine lean like that increases the chance that you'll throw a rod. So I'd just be careful w/ the RPM until you make sure you're pushing adequate fuel pressure w/ the correct FPR.</TD></TR></TABLE>

WOW, still giving out bad advise i see. well, good thing im here still.

OP: your car isnt running lean on the stock ecu, if your settings in the AFC are 0% all across the board atleast. chances are you have a bad TPS sensor, or its out of calibration.

if the TPS checks out ok see if the problem is there without a load, in nuetral rev the engine SLOWLY, and i mean slowly raise the throttle position and see if it does it. if not grab a known good map sensor and try it, but i would put money on the TPS if its around the same throttle angle everytime.



Modified by schardbody at 7:14 PM 2/26/2007

 

Oh I forgot to mention something. I ghetto fixed my IACV with a peice of cardstock so I wouldn't have the ricer idle. I'm sitting at my table now cleaning it with brake cleaner. Could this cause the problem?

Also, about the TPS senor. Are they expensive?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 93eg2james &raquo;</TD></TR><TR><TD CLASS="quote">Oh I forgot to mention something. I ghetto fixed my IACV with a peice of cardstock so I wouldn't have the ricer idle. I'm sitting at my table now cleaning it with brake cleaner. Could this cause the problem?

Also, about the TPS senor. Are they expensive?</TD></TR></TABLE>

Alright, just finished cleaning the IACV. I installed it and still the same thing. ricer idle, but now when I put my finger in the hole for the IACV vacuum, the car feels as if it's going to stall out.

Ideas?

 

Raise your idle. Yeah im with schardbody on this one if you are running a stock p72 then you should have plenty of injector and fuel pump capacity. When you start tunning you might run into a problem.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by smileycvc &raquo;</TD></TR><TR><TD CLASS="quote">Raise your idle. Yeah im with schardbody on this one if you are running a stock p72 then you should have plenty of injector and fuel pump capacity. When you start tunning you might run into a problem. </TD></TR></TABLE>

I just cleaned my FITV, and the car idles perfect! I'm about to go eat dinner cause it's my brother b-day, but when I'm done I'm going to go take it for a ride and see if the blockage of the IACV/FITV vacuum port caused this headache.

I will be back in a few with updates. Thanks everyone for the input so far. I've been dealing with this problem forever, and it needs to be fixed.

 

Just took the car for a ride. The idle is fixed, but the car still hesitates. I went maybe 3 miles to get coffee with my brother and is hesitated more then ever. It almost felt like it was going to die.

I'm thinking it's either the TPS sensor or an o2 sensor... any ideas?

 

i had this problem b4 in 2 cars one had a clogged cat the other tripped a code electronic something ended up replaing the fuse block in the engine bay but i hear eml can be dissabled in a chipped ecu yuppa hope it helps -phil

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nightshocker &raquo;</TD></TR><TR><TD CLASS="quote">i had this problem b4 in 2 cars one had a clogged cat the other tripped a code electronic something ended up replaing the fuse block in the engine bay but i hear eml can be dissabled in a chipped ecu yuppa hope it helps -phil</TD></TR></TABLE>

Do you mean one of the fuses that screws into the fuseboard?

Could a bad o2 sensor make my car bog really hard like that? I have the feeling it might be. I used the voltmeter on the TPS sensor and it was perfect, so this is the only think I can think of...

 

bump, need help bad!

 

Im also thinking it's the fuel filter. The body of my car has over 250k on it, and I'm pretty sure this hasnt been replaced yet so... maybe?

 

almost sounds like something wrong in the ecu.. mine had done that once.. and i took it back and was a bad chip.. but if ur not using the right ecu that could be it

 

mine has been doin that also i was gonna put new plugs in it myy ecu is p06 tuned on crome so i might get a new chip

 

Just replaced the fuel filter with no result. Stil boggs, stutters, ect...

I'm ordering a FPR and Fuel pump tomorrow. Hope that's it

 

Alright, I ordered the parts, should be in soon!

Another question. Could my o2 sensor do this? I figured that if it was bad, I would have a code, but I don't... any possibility there?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 93eg2james &raquo;</TD></TR><TR><TD CLASS="quote">Do you mean one of the fuses that screws into the fuseboard?

I used the voltmeter on the TPS sensor and it was perfect, so this is the only think I can think of... </TD></TR></TABLE>

please explain the process you used to do this. i find it hard to believe you actually took it upon yourself to do this, and did it correctly. i cannot help any further until i am sure you are actually going to take my advise to heart, and not just go uh huh, i did that, and it didnt help.

 

Okay...

I had to look up the wire colors in my helms and it said:
Green = Ground
Yellow = Constant 5v
Red = Should be variable when throttle is moved.

I'm going to school for video/radio. With this program it's required that I have sufficient knowledge in electronics engineering. In my first semester I learned how to check continuity, solder, make basic connectors, and how to use a multimeter. So, having completed my first semester, I know how to use this tool.

Green is ground, so I grounded the multimeter there, next would be the red wire, seeing as it is the signal wire informing the ecu of the throttles position. My number with the throttle completely closed was 0.45 volts and at WOT was a little over 4.2v. Is this bad? I was under the impression that these numbers are okay.

 

bump