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robby j

New Member
If you followed my previous thread, car overheated, blew head gasket, etc...

Everything is put together, planed the head, new thermostat, new temp sensor.

At a stand still, car runs very well, so smooth that you have to check to see that it's actually running. Revs up very well, smooth throughout the entire RPM band.

On the road (under load) it's another matter. Car doesn't have the same power as before, and is sluggish when you put the pedal to the floor. At 4000 rpm, car won't continue to build rpm......it just won't. If I continue to keep my foot down, motor falters and sputters.

I was thinking that ..........
A. It's a vacuum line connected wrong

B. It's bad plug wires, but their characteristics wouldn't change overnight, and car wouldn't run well at a standstill either if that was the culprit (would it?)

C. ????

Here in Mexico, most mechanics aren't familiar with Honda motors (neither am I yet) Car was given a complete tune up with new fuel filter, etc........

Any ideas?

Anybody have a 2.2 VTEC vacuum schematic?

link to original thread below.
https://hondaswap.com/nsx-tsx-rl-tl-cl/bad-news-501893/
 
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check engine light on? if so you need to find out what code.

that's the thing.........it's not on! i have only driven it about 10 miles. but there is nothing visibly wrong, as in something unplugged. what I was hoping for was something like "Did the mechanic......?" from somebody here, but, no :(
 
is it possible the the vtec solenoid is not operating correctly? but that would result in a code and a check engine light, right?
 
My guess is the timing is out. When my dad and I started playing with Hondas and pulling heads we would usually get the timing a tooth or so off wack after. Definately check the timing.
 
My guess is the timing is out. When my dad and I started playing with Hondas and pulling heads we would usually get the timing a tooth or so off wack after. Definately check the timing.


I have thought about that, but, if the timing were off, wouldn't the motor run poorly at a standstill also? The car purrs like a kitten and runs so smooth that you can't tell it's running. but when driving, as soon as you hit 4000 rpm, car bogs!
 
that wouldnt affect power output at 4k. check your vacuum lines, especially if its got a firewall mounted map sensor

Ok, that is where I feel the problem must be. (I hope) It is entirely possible that the guy working on my car missed something. He's a great mechanic, one of the very few that I trust actually, but has never worked on a Honda. I even asked him before I brought it to him..... "Are you comfortable doing this?" He said yes.

So, without me searching up and down the internet, does anybody have a 2.2 vtec vacuum schematic saved on their computer?

I appreciate all the replies. Rob
 
I have thought about that, but, if the timing were off, wouldn't the motor run poorly at a standstill also? The car purrs like a kitten and runs so smooth that you can't tell it's running. but when driving, as soon as you hit 4000 rpm, car bogs!
Still get the timing set. But maybe something in the ignition, dizzy maybe.
 
Ok, so I finally got my license plates. i was driving the car back to my mechanic about 10 miles from my house, and the car behaved PERFECTLY. Ran strong, motor growled as far as I pushed it till about 5500rpm. I thought.....Am I crazy? It ran horribly when I brought it home a week ago!!! But 5 minutes later, it started acting like before or maybe even worse, bogging at about 3000rpm. So, the new characteristics are........

Runs well when cold, shitty when warmed up.

My diagnosis, bad plug wires, or bad fuel pump. I told him to change the wires and check performance, then just go ahead and change the fuel pump (they always fail on you in an inopportune place and time, right, I'm Mr. preventative maintenance!) The great thing about life in Mexico is that labor rates are very cheap. It'll cost me about 30 bucks to have the pump changed and have the tank cleaned. The pump is about 60 to 100 bucks. I'll close this tomorrow with ultimate findings.
 
Could be O2 sensor. Maybe running ok open loop and craps out when it warms up and transitions to closed loop?
 
Could be O2 sensor. Maybe running ok open loop and craps out when it warms up and transitions to closed loop?

Hmmm, I'll check or just replace. Problem persists. I have now changed the VTEC coil (I'm not sure of the proper name, enlighten me here if I am incorrect, and plug wires, and cleaned (again) the EGR valve. After the aforementioned work, car runs like a bat out of Hell for about 10 minutes, as before but stronger, but still bogs after that. Hmmm indeed.
 
10 minutes of good run time. Well, it could be the O2, but I was more inclined towards that if it was at the warmup transition to closed loop.

I'd be looking at the temp sensor and wiring also, based upon the 10 minute good run time. Change the temp sensor the ECU uses to tune with - not the one for the fans or temp gauge.

Keep old parts as you are doing swaptronics - some or all will be good depending upon what the final outcome is.

Not throwing any fault codes?

Good luck with it.
 
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+1 for a coolant temp sensor. I worked on a nx2000 one time that drove me batty for days doing much the same thing. Found out that one of the wires from the temp sensor to the ecu had a problem causing the thing to dump so much fuel when it was warm that it would barely run.
 
+1 for a coolant temp sensor. I worked on a nx2000 one time that drove me batty for days doing much the same thing. Found out that one of the wires from the temp sensor to the ecu had a problem causing the thing to dump so much fuel when it was warm that it would barely run.

hmmm (again) I changed the temp sensor that is on the water neck. Don´t remember if it was on the water neck where the thermostat is located or on the other water neck where the upper radiator hose goes.

Where exactly is this sensor located?

No....no fault codes, neither when cold nor when hot!
 
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I don't have tech data for this car/engine and offer assistance in troublshooting based upon general automotive & mechanical experience and hands on with the D16A6 in my '91 hatch.

That engine has the fan temperature swithch mounted on the firewall side of the block and it has two temperature sensors located in the tranny end of the head below where the dizzy mounts.

Sensors are discreet for fan, temp gauge and ECU. I would assume Honda follows a similar format on other models.

I'm about out of suggestions. :)

No fault codes. Injectors can wreak havoc and not show up on fault codes, fuel pump too, exhaust back pressure, cam timing, dizzy timing, etc. It may or may not be a problem related to the overheat and subsequent maintenance.

Basically, you're going to have to keep turning over rocks until you pick up the right one. Manifold vacum pressure, fuel pressure, exhaust back pressure, actual engine temp, wiring, connections and so on.

I'm suspecting cam timing may be the culprit. Have you ran a compression test? Like cam timing, low compression won't throw fault codes in the ECU. Could have wasted the cat when it china syndromed.

Good luck with it.

Have you checked the timing? No top end power could be a retarded cam.
 
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something that I forgot......I changed the fuel pump, previous one seemed fine and with a nanometer showed a consistent 40psi but it was something that i wanted to do anyway because as I said I just bought the car and wanted to change the pump and clean the tank. nothing worse than a road trip and have your fuel pump die. anyway, new Bosch pump, but a funny thing, 40 psi till the problem reoccurred and then it dropped to 20 or so.

I hope someone says "AHAH!, it's.........."
 
Low fuel pressure isn't good and very well could be the cause of your problems. Probably found it.

Not necessarily the pump though. Check voltage at connections at pump. Debris in the inlet, clogged filter, leak, etc. could be the pump is simply a POS.
 
update: a third mechanic found source of problem. he disconnected the speed sensor and car doesn't hesitate at high rpm. so now have to figure out if problem is in the computer or the sensor. he believes that it's in the computer as no codes are thrown. we'll see (hopefully) tomorrow.
 
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