D15B7 Sputtering/Possible Misfire?

D15, D16, D17 and Mini-Me swaps
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D15B7 Sputtering/Possible Misfire?

By Loaf31
- Sun Jun 19, 2016 10:23 pm #359329 A little background on my engine:

ALL REPLACED 15K OR LESS AGO:
- water pump
- head gasket
- Reaurfaced head
- piston rings
- rods/Pistons
- rod bearings
- crank bearings
- fuel pump
- fuel filter
- valve cover gasket
- spark plug tube seals
- dizzy

Now, the problem. After I rebuilt the engine, everything went fine as far as the engine goes. It ran smoothly and fine. When I give the car a rev or when I'm driving and I put my foot down more than just a tap, it sputters and sounds kind of like its misfiring. Then, at about 3500 to 4K RPMS, it clears up and runs strong. Twisting the injectors in the fuel rail sometimes make the car run fine. Might be the injector connections? A couple months ago, I pulled the injectors and soaked them in seafoam and then tightened the fuel rail back down. Ran with no problems for around 5K miles. Started acting up about 150 miles ago. No CELs. I'm starting to think it could be the MAP sensor since the symptoms are: rough acceleration, smelling of gas, and sudden jerks or hesitation upon acceleration.

Can anyone help narrow down my problem? I'm planning on pulling the spark plugs tonight to see if they're fouled. Then maybe doing a compression test.
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Re: D15B7 Sputtering/Possible Misfire?

By teal_dx
- Mon Jun 20, 2016 8:53 pm #359343 A cheap & easy maintenance thing I don't see on your list is cap & rotor. (or were those replaced along with the dizzy?)
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Re: D15B7 Sputtering/Possible Misfire?

By Loaf31
- Tue Jun 21, 2016 2:03 am #359345 Yeah those were replaced with the dizzy as well, my bad for not posting that.

We took out the spark plug wires and the plug wire closest to the Cam gear had some oil on it and the corresponding spark plug was drenched in oil. Any ideas?? We've already replaced the valve cover gasket and the tube seals
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Re: D15B7 Sputtering/Possible Misfire?

By Loaf31
- Fri Jun 24, 2016 5:26 pm #359367 Well, turned out that it was the throttle position sensor. Replaced it with a newer one that I had laying around and it ran great! Still bogs down a bit, but that may be due to distributor placement. Thanks for all yor help!
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Re: D15B7 Sputtering/Possible Misfire?

By TrailerTrash
- Fri Jun 24, 2016 9:52 pm #359368 did you adjust the TPS correctly? i would imagine if its out of wack that it could cause the bogging.
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Re: D15B7 Sputtering/Possible Misfire?

By Loaf31
- Sun Jun 26, 2016 4:50 pm #359388 Wasnt the TPS, Car is still sputtering.

TrailerTrash wrote:did you adjust the TPS correctly? i would imagine if its out of wack that it could cause the bogging.

How would I go about doing that? :?
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Re: D15B7 Sputtering/Possible Misfire?

By TrailerTrash
- Sun Jun 26, 2016 7:50 pm #359389 super simple :thumb:
http://www.d-series.org/forums/diy-foru ... e-tps.html

im not saying its going to fix your issue but its worth a shot
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Re: D15B7 Sputtering/Possible Misfire?

By Driv-it-hard
- Fri Jul 01, 2016 12:33 pm #359426 Loaf,
Are you still having oil in the number 1 cylinder ? Have you check the spark plug? You may have a bad ring that is leaking oil pass the ring and drowning the plug.
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