D15B7 to D15b Swap
 

Need help guys, first time here, hopefully you can help me with my issue.
I got a 92 civic LX from a friend and it had a D15B7 motor in it. The engine needed replacing.
I found a running D15B and talked to a few guys I know if it would work and all answers were YES.
So here I am after switching the D15B7 with the D15B. Please note that the motors are non vtec.
My problem is that when I start the car, it idles almost perfact, but when I try to give more gas the engine starts to hesitate.
I have fully floored the gas padel and it does not get better. The engine does not die but hesitates like crazy. and when I let it idle it is fine again.
Things that I have changed to troubleshoot the problem:
I have put in a new distributor
a new fuel filter
a new fuel pump
new plugs and wires
air filter is new
I am stuck and do not know what else to look for, any help would be greatly appreciated.
Thanks in advance.

Re: D15B7 to D15b Swap
 

check if you plugged everything into the right sensors. for ex.. purge solenoid to iat. i messed this one up and car idled and ran shitty. check grounds..etc

Re: D15B7 to D15b Swap
 

Triple checked all wiring harnesses and all connections.
What selonoid are you metioning, I thought only the Vtec had the selonoid.
All grounding is good as well.
Thanks

Re: D15B7 to D15b Swap
 

Just an idea, but have you checked the timing and TPS sensor voltage?
Any CELs?

Re: D15B7 to D15b Swap
 

Timing is good, what should be the voltage at the throttle position sensor? Is there anyway to test the sensor apart from checking the voltage?
I tried to unplug the TPS and nothing changes as far as idle or pressing more gas.
Would you recommend to change the throttle body from theold motor and see if it would make a difference.
It really does not make sense because the motor ran fine in the other car. What are the chances of the TPS packing it in before I swapped it.

Is there any difference between the two motors, the d15b7 and the d15b. Please note both motors are non Vtec.

Thanks.

Re: D15B7 to D15b Swap
 

do you have a service manual? it tells you how to set the tps sensor. it is VERY specific.. you can't just take it off and put it back on and expect the car to run.

had the same prob when i first put in my d15b vtec,
got all scared cuz it ran like complete crap, then it was like.. oh.. just set the tps.. then it ran perf.

idk theres probly a writeup somewhere online,
its not hard

Re: D15B7 to D15b Swap
 

My question would be why the motor would run perfact before I purchased it and now after I have installed it in my car, all of a sudden the TPS sensor would be an issue.

Re: D15B7 to D15b Swap
 

And you're positive the MAP and TPS connectors aren't switched around?


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Re: D15B7 to D15b Swap
 

Are those two not the same thing??
I checked all the wiring connectors and none is switched or in the wrong place.

Re: D15B7 to D15b Swap
 

Manifold Absolute Pressure sensor and Throttle Position Sensor are not the same, but have identical looking connectors in a similar location on the harness.

Often people get them mixed up, and the engine won't run right. Just a thought I had while reading your thread.



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Re: D15B7 to D15b Swap
 

Thanks,
It is pretty hard to get a wrong connection for the two, on my car. When replacing the engine I did not have to unplug the MAP sensor and the connection to the TPS was already connected as it came with the wiring harness.
Does anyone know if bad injectors would cause similer problems?
The car starts and idles fine and as soon as I try and give more gas, it starts to hesitate really bad.
HELP.

Re: D15B7 to D15b Swap
 

This is a shot in the dark but your d15b maybe obd0 and have different injector resistance.

I went from a d15b non-vtec and swapped in a d15b vtec and had to change the injectors.

just my 2 cents.

Re: D15B7 to D15b Swap
 

No cels?

Re: D15B7 to D15b Swap
 

No, I do not get the CEL.

Re: D15B7 to D15b Swap
 

did ur firing order get messed up some how? it sounds almost like bad spark...just my guess.that or the timing is off.

Re: D15B7 to D15b Swap
 

New dizzy and timing is good, also tried swapping the ECU. Nothing changed.
Checked the injectors, all good. Running out of things to look for.

Re: D15B7 to D15b Swap
 

Just thought I would throw it out there.

I would test the TPS at this point (don't assume anything, it won't help you solve this problem) recalibrate or replace if needed. If it's fine I would test the MAP sensor and replace if needed, although those external MAP sensors can be a bit hard to find from my experience.

These OBDI ECUs can be a bitch, sometimes they won't just won't set off a code - even when there is an obvious sensor malfunction. It also could be something as stupid as bad continuity somewhere in the harness and you'll have to track it down yourself.

Don't give up, it is fixable.



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Re: D15B7 to D15b Swap
 

did you take the tps off or not?
the voltage has to be set whenever its taken off and put back on (unless you mark its exact position though).

Re: D15B7 to D15b Swap
 

have not had time to look at anything yet. A few guys have said it could be the TPS, will let you guys know how it turns out.
An help in the mean time would be appreciated.