95 Civic, just did a swap from a D15B7 1.5 to a D16Z6 1.6 VTEC. I got everything done, got the timing set, and took it around the block. Everything runs good, idles good and drives good, no check engine light. My problem is...everything runs great at partial throttle, but when I punch it good it falls on its face. It studders, bogs, and bucks. As soon as I ease up it runs perfect again. Then when I try to punch it it just bogs down. Doesn't matter what gear its is. Is this a fuel problem? What do I need to check? Any suggestions would be greatly appreciated.

 

That's an ignition problem. It's worse when trying to accelerate uphill, no? Start by checking your grounds with a meter set to resistance. There should be zero resistance between grounding points like the valve cover and the battery negative post. You can test the ignition before and after adjustments to see how it is doing by either getting a spark tester or:

Performing this test at night or in a dark area will make it easier to see the sparks. Warm the car up completely to normal operating temperature or as hot as your motor gets. Ignition components are affected by heat and problems with those parts may not show up until the engine is hot. Disable the fuel injectors by pulling the fuse or disconnecting them and get a new or known good spark plug. Set the gap of this plug to your vehicle's specifications and make sure it is clean afterward. Wear gloves (welding gloves work great), preferably with latex or nitrile gloves underneath, and remove a spark plug wire from its plug. Connect the good plug to the end of the wire. Hold the plastic deep-well tube by the rubber boot at the tip of the wire end with the threads of the plug touching clean, bare metal on the valve cover. Have an assistant watch you during the test so that the starter can be turned off immediately if need be. Tell the person to crank the motor while you watch the spark, carefully keeping all body parts as far from the plug, motor and metal body parts as possible. You're not just avoiding touching the source of the voltage, but also any grounded metal. Different types of plugs have different colored sparks but usually a good spark is a thick, strong flow of bright pink or white. Little "lightning bolts" indicate a weak ignition. Check all four wires. If the sparks at all of the wires are weak, try holding the threads of the plug against the battery negative post to see if the better ground makes a stronger spark. This will test your entire ignition.

You follow a similar procedure when using a spark tester. If the problem occurs when the engine is cold and doesn't get worse as it heats up, the most likely causes are going to be grounds, cap & rotor, plugs and wires, probably in that order.

 

I'm not at home right now to check, but I'm trying to remember if I even hooked a ground to the valve cover. I'll make sure when I get home and go from there.

 

sounds like your having the same problem im having i have a 89 CRX SI stock motor D16 with ram air intake and 4-2-1 manifold its running good timings on point but when you jump on the throttle it bogs hard and sputters then corrects its self when you let off a little, i thought it mite have been dirty injectors or a MAP sensor?

 

Make sure you dont have the MAP and TPS connectors reversed. That will cause the same problem and happens alot when people do a mini-me swap.

 

I dont think they are swapped, cause when I was putting the motor in I cracked the TPS sensor and connector. I put a new conector and sensor on. Plus I dont think I could swap them cause the one wont reach the other.

 

new spark plugs spark is good then the fuel filter went bad car wouldnt start fixed that its on to the injectors, and i already checked the tps and the map there good i still dont know what it could be?

 

Bogging out under load is almost always the ignition. It will happen more at low RPM, WOT and uphill or when carrying extra weight. It will get better when you give it less gas and the spark doesn't have to jump through as thick a concentration of gasses. It usually won't happen as much at higher RPM because more current is being fed to the ignition. Also because the higher RPM's greater amount of torque is less affected by a given load.

 

I'm going to throw some new plugs, wires, and fuel filter on and see what that does.

 

I changed the fuel filter, didnt help at all. I'm going to pick up a cap and rotor and see what happens. I have my set of plug wires from my D15B7, will they work on the D16Z6 I put in?

 

I think I may have a TPS problem. I noticed it would do nothing when I had the pedal all the way down, no matter what speed I was at. When I got back home, I put the car in nuetral, in the driveway with no load. When I would rev all the way to full throttle, it would cut out as soon as I got the pedal all the way down.

I unplugged the TPS and MAP sensors and plugged them back in. All of the sudden the car would rev all the way, even with the throttle all the way open. When I sat back in the car it had a check engine light. I ran the self diagnostic, and I believe its a 7 and a 41. The 41 I had when I first put the motor in and I had a bad O2 sensor. I replaced it, and the CEL went away until now. So I pulled the 7.5amp fuse under the hood to let it clear, then undid the negative battery cable for a little bit. I put all of that back on, started the car, no CEL, but now I'm back to cutting out at full throttle. Any ideas?

 

Perhaps a loose connection in the TPS circuits. Try having someone hold the connector on the TPS and see if it helps when you rev. Check the terminals and wires for dirt and corrosion. Get a meter and turn the key to on without starting the engine. Locate the 3 wires at the TPS and pierce the TPS negative wire with the black probe. Pierce the TPS reference wire wire (power) with the red probe. There should be 5v. Pierce the TPS signal wire with the red probe. There should be about .5v. Manually open the throttle. The voltage should rise smoothly to about 4.5v at WOT.

 

Which one is negative and which one is the reference?

 

Over gaped spark plugs got me, sometimes the simplest issues throw you for a doozie.

 

Negative is black and you'll know what the other two are when you test them. I believe the signal wire is either red with stripe or has a red stripe.

 

ok, I dont have a black. I have:

red/blue stripe
green/white stripe
yellow/white stripe

I used the green/white as the "black" and pierced it with the black probe.

Then I pierced the red/blue with the red probe. Without moving the throttle at all it was at 2.1 volts and as I applied throttle is slowly moved to zero (at full throttle)

Then I pierced the yellow/white with the red probe. With no throttle it was at 4.97 volts and remained there and never changed all the way to full throttle.

One other thing I wanted to point out is I also cant start the car with the key anymore either. I have to turn the key to "on" and run a jumper to the blade on the starter selonoid and its starts right up.

 

Lol mine was doing this too last week....I swaped ecu,tb, and new fuel filter and didn't change...changed out inj,rail, fpr and added a couple grounds to motor...runs as good as a single slam could

 

the wierd part to me is I can run it as hard as I want, running the throttle up by hand. It revs all the way up until the second I hit full throttle, then nothing.

 

my car was doing this, and a new cap rotor/plug wires solved it. it could also be your grounds, doesnt hurt to change em out, or add acouple.

 

Sorry. I checked and the green is the ground, yellow is reference voltage and red is the signal. Your TPS is not working correctly. You should remove it and make sure the little plastic TPS arm fits into the metal slot in the TB without turning it more than about a quarter inch. The TPS signal voltage needs to move from about .5v at closed throttle to about 4.5v at WOT. I've seen backwards TPS operation when the green and yellow wires are switched, but when that happens it usually starts at 4.5v for closed throttle.

 

I had this problem when i changed my o2 sensor from a 1 wire to a 4 wire. As soon as i put old sensor back in, problem solved. The wiring was fine it was just the sensor

 

Another thing I was looking at is....on the D16Z6 motor, the green/white wire was in the middle. The throttle body on the motor now is the one that came off of the D15B7 I pulled out. The one on the D16z6 got hit during installation and broke the TPS and the TPS connector. So I just swapped throttle bodies, but I left the wiring like it was for the D16Z6 I put in. Maybe I need to swap the wiring on the TPS over to how it was wired on the D15B7.

 

I checked one of our B series's and it goes red-yellow-green. I realize you have a D but I don't have one of those atm. Try switching the yellow and green wires and the TPS voltage should then move in the right direction. Just twist the wires together when you switch them until you see for sure that it helps. Either solder or use butt connectors, both covered in heat shrink for permanent connections. Afterward, set the TPS for .5v idle voltage and make sure it goes all the way to 4.5v. If you're able to do all that, this problem at least should be fixed.

 

just came in from finally fixing it!!!!

I took the picture of my TPS from the D15B7 and wired it that way:

Red/blue in the middle
Green/white closest to drivers side
Yellow/white closest to passenger side

 

i found out what my problem was after 3 days it was year and a half old gas that was in the tank... but tryed to go smog yesterday and it was all bad didnt pass "NO" was off the chart like a 1500 and max meas was like 800 think my cats bad cuz i just put a brand new o2 sens and plugs, injectors, oil change, fuel filter but i do have headers and a ram intake going to get a new cat today and re-check for any leaks and try to test again mite have to through the stock intake and manifold back on to pass IDK