Bad stutter and backfire

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silva95teg

Member
I just finished putting in a 2000 b18b into my 1995 integra ...... i finished it on sunday and it ran good. I drove it about 250 km and now if i punch the gass it almost dies then comes back to life , and if i punch it and it is in second once the rpms are high it starts back firing ..... i have changed the plugs , the wires and checked the timing .... i dont know what else it could be ... any suggestions , or has anyone had the same problem ? One other thing though , if i give it gas slowly it seems to run fine also it idles fine and isnt throwing any codes.
 
check your timing. it could be that. seen that be a lot of problems for people. could also be in ignition problem, i'm thinking possibly the distributor is going bad.
 
the dizzy only has 50000 km on it though ...... and the timing is good i checked this morning. i am gonna try rotor today , but i have a spare dizzy if it comes to that.
 
i dizzy can go bad on 50km. mechanical parts are always subject to break. try the rotor, but i doubt that's it. good luck, keep us updated.
 
could be a vacuum leak. anything like that. possibly a blown head gasket. i would get a leak down and compression test done.
 
The thing is it runs great when it isnt doing that ..... it idles fine , starts fine , doesnt go through coolant or oil , oil is clean. spark plugs look a little more on the whitish side than tan so it might be a litle lean although the other motor ran rich ...... also the little black thing on the back of the intake manifold , it looks like a little solinoid , is it supposed to make an audible humming noise when the key is on but the car isnt running?
 
you would have to take a picture. the only thing that should make noise is the fuel pump priming. you get accessory noises from the electronics going though.
 
i think the thing is called an iac or something. Anyway can anyone confirm that when running the obd1 harness from the shock towers back to the computer which is obd1 as well , that when using an obd2 engine harness that there are no pin outs that have to be changed. When i did it there was only one connector that went to the tranny that i had to take off the obd1 engine harness , and i had to run a tach signal from the dizzy , other than that it all just plugged in.
 
I wanted to clarify on the problem a bit......

ok first off these are the things i have checked or changed.
1. Cap and rotor
2. spark plugs
3. plug wires
4. Timing (set right on the red mark) (and the connector was shorted)
5. I cant find any vacuum leaks

Here are things that have been done ......

1. The evap canister is not connected because it is for the obd1 motor so the lines are just pulled off and left open.
2. The evap purge solinoid has been removed and the hole plugged.

Here is my best description of the problem.....

The engine starts fine , the oil is clean and full , and the coolant is also good. The engine does not smoke at all. The fuel filter has been changed less than 20000 km ago.

Ok now that i ahve that all out of the way here is what happens. If i just start the car and have it idleing , then have the hood open and manually open the throttle by hand, all the way quickly, the engine bogs and seems to back fire. However if i dont open it all the way and rev to 3000-3500 and then open it quickly the rest of the way there is no hesitation and it revs up fine.

Now if i am driving the car and dont give it too much throttle , it seems to run and pull just fine. If i am say in second gear at about 2500 rpm and mash the throttle down to the floor it stutters and backfires and loses
power until the rpms have climbed to 3000 - 3500 then it pulls fine.

if i am in second gear and have the rpms above 3000 then mash down the throttle it runs fine, pulls alright but seems a little weak above about 5500 rpm.

Just to clarify it does this in all the gears but second seems like the worst. If i am at 2500 rpm in third and mash the gas it still does it.
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I am including some pictures of the plugs as well as the thing that makes the loud humming noise.</span>

Let me know what you guys think , i really appreciate any help you can give me.

Just another note , when i first got the engine in it ran fine, it was only after a long hwy drive that this problem started.




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i would check your fuel pressure. those plugs are white. you are running lean. i had a similar problem recently and it was the distributor. it didnt' throw a code for the longest. but after everything you say that you have changed or checked, those are your next efforts. fuel pressure and dizzy (it could be one of the mechanical pieces inside your dizzy like the crank position sensor).
 
If it makes any difference it doesnt seem to do it in the morning when it is cold. It starts up as soon as the engine warms up a bit.
 
I just finished my b18b swap in the eg hatch and this sounds like the problem i was having.... check your fuel pressure and then swap the dizzy since you said you had a spare one... My problem ended up being the dizzy.
 
got it fixed .... fuel pressure was good , it was the coil ...... although when the coil was cold it tested fine, once it was hot though it went to shit.
 
That makes sense. Glad you got it figured out.
 
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