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idle to redline in neutral....boost = sputter

PostPosted: Sun Oct 26, 2014 2:01 am
by outinnowhere3193
Ok my setup for this car I have is a ST165 us car and I installed a ST185 JDM into the car using the injectors and intake with sensors. I didn't have a AFM so I pulled one from a NA car.

At first the car wouldn't rev past 3500...sputter out like it was getting to much fuel....I pulled the plugs and verified I was getting to much fuel so I opened up the AFM and adjusted it. At about 8 clicks from stock position the car idles good and revs to redline well. When driving it's a 1/8-1/4 throttle....anything pass that equals a sputter.

I adjust it to where it's about 18 clicks from stock and it idles horribly and sometimes dies but revs nicely to redline and when driving if I slowly roll throttle I can even boost in low gears smoothly. At 60 mph I can maintain it with no problem but as soon as boos comes its a sputter. I tried doing a downshift and I carried the 4000-5000 rpm in 3rd smoothly with the response to throttle.

So basically if I set it where it doesn't idle I can NA rev well but nothing on boost and if I set it where It idles and still revs to redline it wont even hold speed at 60.

Any thoughts? I am using a Walbro 255 fuel pump......I just thought could it be as soon as I hit boost fuel pressure goes up and that's my issue?

Tuesday I'm suppose to have my wideband so I'll be able to see what's really happening.

Re: idle to redline in neutral....boost = sputter

PostPosted: Sun Oct 26, 2014 2:38 am
by outinnowhere3193
oh and my speedo isn't working.....does the car need that working to know how fast I'm driving?

Re: idle to redline in neutral....boost = sputter

PostPosted: Sun Oct 26, 2014 7:46 am
by underscore
For starters get the right AFM for the ECU, you'll have a hard time getting it running right without that.

Re: idle to redline in neutral....boost = sputter

PostPosted: Sun Oct 26, 2014 11:24 am
by outinnowhere3193
Where do you get one? I've looked at the parts store and on rock auto as well as ebay. I even made a post about it like a month ago I got told a NA one would work.

Re: idle to redline in neutral....boost = sputter

PostPosted: Sun Oct 26, 2014 5:17 pm
by Meenya
underscore wrote:For starters get the right AFM for the ECU, you'll have a hard time getting it running right without that.


+1

Find out what ECU do you have (part number) 90-91 is different than 92-93
Try to find out what engine do you have 92-93 came with 9 studs exhaust manifold
Look for correct AFM for your application

To add for the confusion there is also RC AFM & ECU which are different

Just because someone said NA will work, doesn't mean it will work correctly. HTH

Re: idle to redline in neutral....boost = sputter

PostPosted: Sun Oct 26, 2014 6:17 pm
by outinnowhere3193
The car is a 88 and the motor is a 91. I'm using the 88 wiring n ecm.

Re: idle to redline in neutral....boost = sputter

PostPosted: Sun Oct 26, 2014 6:19 pm
by outinnowhere3193
Will a 91 afm work with the 88 ecu? If so I've located one.

Re: idle to redline in neutral....boost = sputter

PostPosted: Sun Oct 26, 2014 6:24 pm
by outinnowhere3193
Heck just thought can someone tell me what part number or numbers I need to get

Re: idle to redline in neutral....boost = sputter

PostPosted: Mon Oct 27, 2014 12:37 am
by ___Scott___
Will a 91 afm work with the 88 ecu?


I'm pretty sure the 90+ AFM doesn't have the shut-off switch for the fuel pump that the 88 ECU and wiring will require. It will be obvious if you need that switch and don't have it when the engine starts fine, but then dies about 3 seconds later.

Re: idle to redline in neutral....boost = sputter

PostPosted: Mon Oct 27, 2014 12:56 am
by outinnowhere3193
So besides the switch it will work correct? I can work around a fuel shut off switch.

Re: idle to redline in neutral....boost = sputter

PostPosted: Mon Oct 27, 2014 3:23 am
by ___Scott___
The switch in the AFM is a safety feature that causes the fuel pump to shut off in the event of an accident that also stalls the engine. You really don't want to experience a pressure fed fuel fire, there will be enough other "excitement" in the event of an accident where a fuel line ruptures. So, you shouldn't try to work around it unless you also implement the same safety functionality.

That being said, I believe the 90+ (non-RC/CS) will work if you "hot-wire" your fuel pump relay to bypass that safety switch (though I've never done it.)

Re: idle to redline in neutral....boost = sputter

PostPosted: Mon Oct 27, 2014 10:29 am
by outinnowhere3193
Well we will give it a try then. Maybe I can add the switch in?.... who knows I'll figure it out n post back in.