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So I've owed an 85 rx7 for 15 years and had an 8 about 9 years ago. A friend of a friend heard in into triangles and asked for help with his 04 manual rx8. He got it from some really bad mechanics or something because it has a real rough start, doesn't want to idle and won't go above 5.5k rpm. Removed the upper plenum and found the throttle body plate had been drilled to allow more air (dumb) and they're were two holes drilled into the upper plastic plenum then jb welded shut..... I soldered the throttle body plate holes and fixed the upper plenum and installed 4 new coil packs. There are so many things wrong with this thing and after reassembling it starts a bit better but still having issues.... looking for some help. Thanks members!
Motor been rebuilt? Looks like a way to fake a higher idle.
If they thought that was a good idea I'd hate to see the internals
funny enough the cousins are painted but not the irons.... seems bass akwards from rebuilding history. Lol and there is noticeable sealant poking between the housings and irons from the compressing of an engine taken apart. So is have to lay money on that it had been taken apart.... also the vac lines to the oil injectors are crimped close... current owner had no idea and didn't know about prefixing. Not his fault, he was never told.
Motor been rebuilt? Looks like a way to fake a higher idle.
If they thought that was a good idea I'd hate to see the internals
I sent a few pic responses but still waiting for mod approval.... any quicker way to get full access? Been a member of the rx7club site for the better half of 2 decades. Lol
Oh boy , you real have been dropped in it with that one . First thing i'd do in a case like that is compression test it to make sure you aren't wasting your time trying to fix the unfixable. These things will still run ok to way below the minimum specs but there is a limit to that.
Oh boy , you real have been dropped in it with that one . First thing i'd do in a case like that is compression test it to make sure you aren't wasting your time trying to fix the unfixable. These things will still run ok to way below the minimum specs but there is a limit to that.
from past experience I'm assuming the only way to compression test is with a rotary compression tester or a dealer then..... I told him with a standard tester it will only show your highest compression rotor face but not the other two. They would fall below the best chamber and not show, correct? Thanks for the help!
Same for the front rotor.... new plug on bottom FL and top is FT.... also looks dirty like not firing..... are the trailing plugs controlled differently? I'm used to dizzy firing plugs with the first gen so I'm wondering if they hacked into the harness and deleted the trailing plugs on accident? New plugs for the trailing need picked up from the parts store but till then I'm gonna try using 2 plugs for my 7 with the 4 prongs..... seems like the same depth till I get the new ones. Also put sea foam in the tank to try clearing out gum and junk. And these trailing plugs were cleaned and installed only about 20 minutes of idle time before they looked like this. Looks like lots of crud gathering on the T plugs but can't imagine that's just from sea foam?
Last edited by Risingsunroof82; 09-07-2021 at 12:51 AM.
You can just use a conventional tester with the check valve removed . Just video the meter while cranking ...you can also use the video to work out the crank speed. The values will be lower that way but you get to see the difference between the rotors . Then you can just use a fitting with check valve to find the max. value.
You can just use a conventional tester with the check valve removed . Just video the meter while cranking ...you can also use the video to work out the crank speed. The values will be lower that way but you get to see the difference between the rotors . Then you can just use a fitting with check valve to find the max. value.
thanks! So sounds like you use the video on slow motion to see the peaks and valleys then?
Side note, I've been confused by the vac line routes with this CAI..... the main and secondary shutter valves were straight to the lower intake vac ports and the air pump was left hanging.... am I missing something here? Lol
No ...you only need to fully depress the acc. pedal ...that shuts off fuel .
Also :
I see the front vac off the intake goes to a port on the oem intake box but first.... where to now with a CAI? and what about the rear intake vac port not shown in that diagram? Also the upper shutter valve sticks closed at dead shut. For the time being I blocked it from going almost dead shut for trouble shooting purpose with a zip tie on the linkage to keep it from going totally closed.... about 1mm open for the time being..... tried getting it freed up but won't stop binding. But even manually moving it at idle doesn't change the rpm or anything. Sounds funny but then again it's not a Holley 4 barrel so I'm learning this part. Thanks a ton for the quick help! I really wanna help this guy out, don't want him to be another reciever of a basket case and make a bad name for the rotaries. 👍
Also, are the three solenoids on the back of the vacuum chamber all the same part number? For some reason these small things have been hard to find?! Like the 2 vac ports on the lower intake.... don't see the second one in diagrams.
Trying to fix the bad idle issue and so far have replaced the whipped coils and plugs, fixed the hole in the throttle body and intake, replaced the purge selenoid and cleaned the crank sensor and maf sensor. What's the next step cause I'm getting frustrated. It has an exhaust leak at the header but could that make that much of an issue?
If you had an obd reader you could post some of the idle parameters .......... that would help diagnose. These cars are extremely sensitive to maf setup issues so if any mods done there ....that's first thing i'd suspect !
09-05-2021, 06:28 PM
