RPM flutter problem

7mgte

New Member
Jun 9, 2010
10
0
0
Washington
Just finished a motor swap in my 84 pickup. I put a JDM 7mgte in place of the old 22r. Finally got everything running good, so I take it to have an exhaust system installed. On the way home at around 3k rpm the motor would surge and the rpms would flutter. I limped it home and am trying to come up with ideas for troubleshooting in the morning. I am fairly new to the 7m so any help big or small is greatly appreciated.
 

7mgte

New Member
Jun 9, 2010
10
0
0
Washington
I figured it would probably be vacuum somewhere but just wanted to get someone else opinion too. No build thread yet, I am working on it though. Thanks
 

Nick M

Black Rifles Matter
Sep 9, 2005
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Pull your diagnostic codes also.

How does it idle? Because cam timing creates a vacuum problem, which is why they run bad even one tooth off. It isn't unreasonable to say the tensioner might not be tight on the belt is it?
 

7mgte

New Member
Jun 9, 2010
10
0
0
Washington
Sorry I misread your post, I have a homemade bracket on the alternator in place of the stock adjustable bracket. I have not touched the timing belt or the tensioner. I will take the cover off and have a look though.
 

7mgte

New Member
Jun 9, 2010
10
0
0
Washington
No intake leaks that I found. I checked the timing and it was at 0. I then turned the cps to get it to 10 degrees. However it still idled low at around 500-600. So i adjusted the throttle screw to get it to about 800. When I rechecked the timing it was above 15 and the cps was turned all the way down. I tried returning the throttle screw but it was still at 15 degrees. Any help?
 

Nick M

Black Rifles Matter
Sep 9, 2005
8,897
40
48
U.S.
www.ebay.com
If you are sure on the engine timing, which is hard to do since there isn't a mark on the crank timing pulley, then the CPS also could be out of time. The tooth off is just a thought. Especially with timing at zero. Somebody prior might have done that to keep it running right, instead of correctly timing the sensor.
 

7mgte

New Member
Jun 9, 2010
10
0
0
Washington
Well i never did get it back to 10 degrees which is what my manual says it should be at. Could this be because the tps is out of time?