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RX7 FD wont rev past 3k RPM!!

Old 03-26-18, 12:13 PM
  #26  
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Coil test

This is how i tested the coils and they were within specs, but i went ahead and swap the leading for fc. My car is single turbo runing 13psi might be pushing 340rwhp on dyno dynamic. I have also hks twin power. The fuel pressure was alarming to me, but the car was still runing, but when i passed 3k rpm would misfire. I also thought that my fpr was bad, but i did the fuel pump rewire and idles better and no misfire.. its like a freaking miracle after testing components. I understand the frustration you are going throug, man.
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Old 03-27-18, 03:46 PM
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Thanks for the info Red94fd, much appreciated. I will give this a try over the coming weekend.

A friend has a complete engine harness in good condition as well, might give that a shot too and switch out my old one.

Cheers
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Old 03-27-18, 05:22 PM
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Good idea, its a lot of work
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Old 04-06-18, 11:52 AM
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Hey guys,

No luck so far. Took out the wire loom but couldn't switch it out with a different one because apparently there are differences with the RX7 FD wire loom and the Efini RX7 FD wire loom ....... anyone know this for sure???? I didn't take it out myself, but my mechanic tried it and didn't fit up. Will check through my wire loom in its entirety to see if any wires are broken / bad connections / loose wires etc...

The fight goes on!!! Still working on other aspects of the car as well. Got my wheels already and some other bits are on the way - rotors, SS lines etc... so at least there is SOME progress in other areas

Cheers
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Old 05-19-18, 06:49 PM
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Hey Guys,

So after sometime still no progress. Pulled the entire loom out. Checked each wire and plug, all in tact. Got the ECU checked. Checked out fine. No issues there.

Changed the coolant temp sensor. Same issue.
Got the fuel pressure coming from the pump at 82psi which is within range (71.1 - 106 psi according to shop manual). Added an adjustable FPR amd played with that. Still same issue.
Tried two separate coils. Same issue.
I am totally confused at this point and dont know what else to try. Any suggestions? Thanks.

Cheers
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Old 05-22-18, 08:35 AM
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Bump for some help
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Old 05-22-18, 03:51 PM
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You may want to post some engine bay/rat's nest pictures and maybe a video of it doing it.

Another possibility is something with the secondary injectors, like them being stuck, not firing, bad wiring to them, etc. They come online at 3000 rpm or so.

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Old 05-22-18, 03:56 PM
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Originally Posted by DaleClark View Post
You may want to post some engine bay/rat's nest pictures and maybe a video of it doing it.

Another possibility is something with the secondary injectors, like them being stuck, not firing, bad wiring to them, etc. They come online at 3000 rpm or so.

Dale
Thanks Dale,
I will try to post up some videos and pics soon.
Will also recheck my wiring to the secondaries. I know they are not clogged for sure. Checked both primary and secondary injectors outside the car on a fuel injector machine - cleaning, flow rate etc... and they all checked out good.

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Old 05-22-18, 03:58 PM
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Also, can the plugs to the primary or secondaries be mixed up? Meaning, can a secondary plug be plugged up to the wrong secondary injector?
I'm not saying primary plugged on secondary and vice versa. Hope you understand what I'm saying lol...

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Old 05-22-18, 04:58 PM
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You can make the computer ignore the limp mode by switching the ignition off and back on without letting the engine stall. Rev it, key off, key back on straight away.
Now you will be able to drive it if is was in limp mode and soon enough you will get fed up of doing this every time you start the car and you will end up buying a stand-alone.
Hope this helps.
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Old 05-24-18, 09:05 AM
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Thanks for all the replies guys. Appreciate it. Spoke with some RX7 owners in my area and they all seem to think the computer is stuck in limp mode for whatever reason.

I think I might pull the trigger and get a Power FC and take it from there. This whole trouble shooting is getting pointless at this stage. Will order one soon and then post back the results.

Cheers
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Old 06-24-18, 11:20 AM
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Quick question guys. What's the voltage u guys see to the fuel pump normally? (Non hard wired pump). I am seeing 7.5V at idle. The car idles horribly as stated before. I will be rewiring the pump in short order, but wanted to know if that was normal. When I rev it or at least attempt to rev the engine, the voltage barely goes up to 8V. Or do I have a bad fuel pump resistor (under brake master cylinder)??

Will be ordering the Power FC soon.

Cheers
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Old 06-29-18, 03:30 PM
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Originally Posted by Trinityevo13 View Post
Quick question guys. What's the voltage u guys see to the fuel pump normally? (Non hard wired pump). I am seeing 7.5V at idle. The car idles horribly as stated before. I will be rewiring the pump in short order, but wanted to know if that was normal. When I rev it or at least attempt to rev the engine, the voltage barely goes up to 8V. Or do I have a bad fuel pump resistor (under brake master cylinder)??

Will be ordering the Power FC soon.

Cheers
BUMP!! Any help would be appreciated. Thanks
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Old 06-29-18, 11:42 PM
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Before the hard wire mod I did several years ago, I seem to remember I did a voltage check before the hard wire mod. I believe from memory I got around 11 volts at idle and around 12-12.5 with the engine revved. This is about 1.5 volts down from the voltage expected at the battery. 7.5 to 8 volts is definitely low. No way you can maintain your fuel pressure as demand goes up.
Mike
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Old 06-30-18, 06:48 PM
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Thanks Mike. Appreciate the info. Will be doing the rewire once I get the time. Hopefully this weekend and I will post up some results.

Cheers
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Old 06-30-18, 08:39 PM
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Do you have an amp installed? I'm having a similar problem on my 93 Touring. Looking at getting the power FC too.
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Old 07-02-18, 08:48 AM
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Originally Posted by edd956 View Post
Do you have an amp installed? I'm having a similar problem on my 93 Touring. Looking at getting the power FC too.
No amp installed, in fact, no radio what so ever.
Whats the issue with the amp being installed? Just trying to connect how it might be related to this issue...

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Old 07-02-18, 12:22 PM
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Electrical drain; Maybe clean the grounds. I'm looking at doing this on my next day off.

http://www.dirally.com/forums/showthread.php?15711-My-proof-that-DIY-grounding-kits-work
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Old 07-02-18, 02:15 PM
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Originally Posted by edd956 View Post
Electrical drain; Maybe clean the grounds. I'm looking at doing this on my next day off.

My proof that DIY grounding kits work
Thanks edd956. I have checked the grounds in the past and they looked good, will double check all to make sure.

Cheers
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Old 07-04-18, 10:41 AM
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A similar post was made on the Facebook group rx7 rotary some guy claimed it was a clogged cat.
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Old 07-06-18, 03:56 PM
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Originally Posted by edd956 View Post
A similar post was made on the Facebook group rx7 rotary some guy claimed it was a clogged cat.

Thanks edd956, I have the cat removed and a resonator installed. 3" from the stock downpipe and then a HKS Hi-Power cat back exhaust. Could the resonator be blocked....maybe... but it was thoroughly checked before install. If nothing else seems to work I will recheck the resonator to be sure.

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Old 07-09-18, 07:43 AM
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Hey guys,

Finally had some time to do some tests on the RX7.

1. Rewired fuel pump as discussed here on the forum and no change. Doesn't seem like a voltage issue to the pump. Even tried a straight wire from the battery terminals to the pump and still no change. Although the car ran slightly better at idle. The car could actually idle long enough to be warmed up to operating temps.
2. Tested the coils finally. The Trailing plugs are firing strong but I get zero spark from either of the Leading plugs. I suspect a dead leading coil and will remove it soon to get it checked properly. I will check all the other coils as well.

Thanks for the help, I will post up any further progress. Will try to remove the coils this week

Cheers
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Old 07-09-18, 02:23 PM
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Man,.. you have been chasing that for a long time. Finally you are getting somewhere.
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Old 07-09-18, 02:33 PM
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Originally Posted by Red94fd View Post
Man,.. you have been chasing that for a long time. Finally you are getting somewhere.
Lol, tell me about it. Time is my main enemy. Only so many hours in one day. But hopefully my schedule allows for more time with the FD
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Old 07-22-18, 12:42 PM
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