2nd Generation Specific 1986-1992 Discussion

S5 swap won't rev and has no power

Old 07-16-2011, 12:22 PM
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So I recently became the new owner of an 1986 Rx7 with a complete S5 swap. From what the previous owner told me and from what I've seen so far the swap was done the hard way and all S5 components were used and the wiring harness swapped and modified.



The car came with the Pineapple racing ACV block off, a BACV blockoff, rats nest removed, tein s-techs, tokico shocks, some no name strut braces, aftermarket seats (i had to build custom brackets to get a decent fit) and a Walbro 255. Also the 6-port stuff was disabled (smog pump is gone and the exhaust is a straight pipe from header to two cans in the back)



Since i've owned the car I've replaced the three manifold gaskets, the front cover gasket, water pump gaskets, injector o-rings, removed and cleaned the 6 port sleeves, repaired and cleaned up the wiring, replaced the clutch slave and master cylinders, replaced the thermostat,added a double groove pulley to the alternator and flushes and refilled all the fluids. I also removed the rats nest and re-sealed and capped all the unused vacuum ports.



Since completing all of this and re-timing the car my cranking and idle has increased dramatically. The car revs freely to redline when the clutch is depressed of the car is out of gear. MY problem though is while under load the car breaks up and stumbles badly when trying to accelerate. It doesn't stop at 3500 rpms like i've read about. In fact it will rev to redline under load but only gradually at very little throttle. IT will not rev at full throttle under load and shudders if to much pedal is applied.



I've read about tps and the grounding issues but i've already spent a month getting the car this far. I don't want to waste more time chasing the wrong problems



If anyone has had this issue and can point me in the right direction with my next repairs/ troubleshooting I'd greatly appreciate it
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Old 07-16-2011, 04:09 PM
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i want your savanna badge
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Old 07-16-2011, 04:23 PM
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Originally Posted by RicerJ View Post
i want your savanna badge


I've been thinking about parting it since I'm not a big fan of gold packages



Also I was thinking, if anyone knows, since the car revs to redline while not in gear can I rule out TPS and focus on grounding and maybe fuel?
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Old 07-16-2011, 06:12 PM
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OK went ahead and cleaned/sanded crude off of the factory grounds and added a second 4 awg ground to the negative battery terminal. Seems to have helped some but now a new problem has shown up. As the car warms up the acceleration problem returns. It's almost like once the car gets to temp the timing jumps out of whack.
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Old 07-16-2011, 06:32 PM
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Originally Posted by RicerJ View Post
i want your savanna badge




lol i've give the badge to the person that figures this out XD
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Old 07-16-2011, 06:57 PM
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lol so the ecu and everything from a s5 is used?
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Old 07-16-2011, 07:15 PM
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Originally Posted by RicerJ View Post
lol so the ecu and everything from a s5 is used?


yeah as far as I know. The whole engine harnees is bulky now because everything has two plugs. Looks like all the sensors and stuff now have s4 and s5 wiring. (s4 plugs just hang there) Supposedly the car was running fine before he had the front cover off to fix a leak. He thought it was a CAS problem, i'm thinking its timing, temp, or tps problem
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Old 07-16-2011, 07:53 PM
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reset the timing and check the ecu number
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Old 07-16-2011, 08:24 PM
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Originally Posted by RicerJ View Post
reset the timing and check the ecu number


where can I find part #s that correspond to S5 ecu's?
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Old 07-16-2011, 09:04 PM
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I'm going to try and reset my timing again but there are no marks on the pulley. The last time the timing was set I



removed the front two plugs,

turned the rotors until and apex seal was visible in the top hole

marked the pulley at the timing pin

turned the rotors until the apex seal was visible in the bottom hole

marked the pully again at the pin

measured the diameter of the pully

measured the distance between the two marks

split the difference and made my mark (yellow dot)



I just thought of something, do I need to do this for the rear rotor as well to get my "red" dot?



Is there a more precise way of finding the timing mark on a pully without one? Does the keyway on the IS represent TDC?
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