i recently purchased a 89 rx7 gtu from a family friend. the car has 70k miles on it and is in great shap in and out. however the car did sit for 5 years undriven. so there are a lot of rusty bolts under the hood. all hoses and belts are in good shape, i just put a brand new alternator in it and a fresh battery. Now the issue im having is when the car cold starts it revs to about 3 grand which i read is normal, but when the idle drop it wont stop and will eventually die if i do not hit the throttle. now if i drive it right after i start it it will drive, feels like its not getting all its power and will not rev past roughly 3500 rpms in gear. BUT out of gear sometimes i can rev it to redline and other times i will fuel cut. im not sure if it has power loss or not, im comming from driving a well built 240 so i had no idea what to expect. does anyone have any idea what could be going on? everything is all stok 100% i will appriciate any imput given thankyou!

If you haven't already, your entire fuel system from tank to injectors will need to be flushed. That includes tank dunk, possibly new pump, filters, injector flush ETC. It's better to be thorough and do it all properly to avoid hassle of tracking down a clogged or failed component later.

What he said; when mine had that problem all I had left to do was up the fuel pressure a little bit (bigger injectors) and then just floor it for a while; burnt out a lot of gas, but it cleared up the smoke and got my revs responding properly.

im trying to figure out the best wat to go about this, where to start....

Since it's been sitting for a while try putting a can of seafoam through the gas. You can buy it at autozone. It actually is supposed to clean out injectors and your engine and can also clean out carbs. It provides lubrication too and stabilizes gas. It works real well for me so I think you should try it.

degrease the connections around the EOMP and at the pump/ feedback sensor



the intermitant rev cut is typical of EOMP fault limp mode on s5 ( a CEL light code checker will confirm )

,, and on s4 cars it is usually related to bad earthing and sometimes fuel pump 2 speed circuit

so far i have:



changed oil and filter



changed spark plugs and wires



changed fuel filter



changed air filter



replaced alternator



all new belts



new battery



i have no idea what "EOMP" is if someone could let me know that would be great, so far no luck as far as holding idle, also still has no power and seems to fuel cut under load at about 3500rpm. at idol i can rev to whatever tho just have to keep the foot on the gas pedal to prevent it dying, its only under load when it fuel cuts. i think the next step is to:



drop gas tank and clean out



blow out fuel lines



check fuel pump filter and quality of entire pump



pull injectors and inspect / soak in gas? to clean... if someone has a better idea on what to do with injectors please lmk



check fuel rail



if anyone has any other idea on what else to do please let me know.

Electric Oil Metering Pump,,, if it aint plugged in ,, or its faulty

,, your car WILL **** itself a few minutes into every drive and will then NOT allow boost or revs beyond 3.5-4K

thanks

just double check grounds and tps just to get those off your list of things to check

are either of these worth purchasing? i will be checking my grounds and tps after this post.





Mazda RX7 FC S5 2nd Gen Oil Metering pump (OMP)





http://cgi.ebay.com/ebaymotors/Mazda...Q5fAccessories





89-91 MAZDA RX7 FC3S HIGH VOLUME OIL PUMP 13B





http://cgi.ebay.com/ebaymotors/89-91...Q5fAccessories

you dont need the internal main oil pump,, but you MAY need the external oil metering pump if yours is faulty

but first you must use the FSM to test the OMP feedback senders and the motor windings

( and also that end of the ECU mother board ) before blindly replacing parts



the ( no revs beyond 3500 ) fault on a s5 will almost certainly be in there on that lot

( a similar symptom issue on s4 cars is poor sender earth and shield grounds )

,, the stalling will likely be a unmetered air leak



find the FSM and do the OMP checks with multimeter

if you are a little bit cluey you may wish to do a code check also

( but am expecting codes 20, 26, 27 and or 37 to be present--telling exactly what i have posting since post 1 )

if i do not have a tps tester how can i tell if it needs to be adjusted?

volt check it people will tell you one way is better but do both if you can to make sure its all good

wow that was quite a task getting to the omp and eomp. removing the fan shroud is a damn headache without removing the clutch fan. anyways so ive removed airbox intake pipe top coolant hose and fan shroud the as far as testing the OMP feedback senders and the motor windings, idk where the feedback senders are and what is "motor windings"?

yea umm mine was missing half the bolts for fan shroud so i had like 2 or 3 lol

it wasnt even the bolts that was the issue it was jimmying it around the top of the radiator and the fan https://www.nopistons.com/forums/pub...1047683358.gif

Mine wasnt even that bad

picked up a multimeter today but i dont have a clue as to what i am checking for or what the number should be reading,

Look in the fsm

i have the fsm and it does not say.

you can see how to check the tps the a volt meter by doing a google search as far as readings go on the eomp idk you might get those with a google search too

d-17 on this link http://foxed.ca/rx7manual/manuals/19...ion_system.pdf

Did you by any chance try swapping out the secondary injectors? My buddy had this same problem that it would not rev past 3500 we swapped out the secondaries for some known good injectors and boom car was running.

what was wrong with the injectors???

honestly i do not understand what the fsm is telling me to do....

You can build the test light for like 12 bucks from radio shack

so i went through with every plug to the engine and pulled them apart and cleaned them, many of them were oxidized. i tested the harness plug to the eomp and it was getting 12 volts , the eomp looks to be in great shape it was one of the only plugs not oxidized. the ground behind the intake mani on the right was completely oxidized i dont know where all the grounds are located. so my next thought is that maybe the oil pump itself is bad? or the injectors... not sure... i did not think this would be as dificult as its becoming

Its a rotary they are a fun challenge and worth the time they take

time to blow out fuel lines, check pump and injectors, does anyone know how many grounds are on a s5 harness?

Sorry to threadjack but I'm having similar issues with my 86 S5 swap. The car will rev past 3500rpm under load but not at heavy throttle I can go all the way to redline but only slowly under light throttle. Should I pursue grounds first or try to mess with the tps? Btw EVERY vacuum line was checked/replaced and unused ports capped and sealed so don't believe that is the issue also car revs fine at full throttle when clutch is in or out of gear.

make your own thread but a s5 into s4 takes a bit more work then a s4 to s4 there should be a thread somewhere in the swap section of this forum that has your question if you cant find it start posting in relative sections

the unfortunate part is I didn't do the swap, the car was purchased like this as a project

how much of the s5 stuff is gonna be ran? how much s4 is gonna be used? but again start your own thread do a relative search in other sections and also when you make your own thread list whats being used from each series and you should get the answers you need

ok so i got a new/used eomp in good working condition. that has been replaced now im just waiting for a ecu to come in and we will be on the road in no time!!.... i hope

good luck

thanks man, but i just realized the ecu in my car is a N351 and i ordered a N350, does anyone know if there are going to be problems with this being that the N350 is california emissions???

Do you have a check engine light? if you do use the onboard diagnostics system to find out what circuit the problem is in...



Also checking the OMP is easy if you access it from below, and it DOES NOT require removal. Just have to reach over the undercover past the swaybar up to the connector. I will say it is easier with the undercover removed though.

Check it with a multimeter per the FSM.

If everything is good at the OMP (or MOP as the FSM calls it), follow the wiring up the front of the engine, there will be a connector right next to the TPS connector that connects the OMP wiring to the engine harness. verify everything is reading right right from that connector as well. I found my problem was the wiring that goes to the OMP. The lower connector was bad, breaking the circuit. It tiggered a check engine light and limp-home mode. In limp home mode you cannot apply much throttle or she'll lose power. I have two threads on that very topic.



I found after ordering a new ECU that mine was fine...



Do a search for your ecu code, there is a thread that goes through what ECU goes to what application.

well the ecu arrived today and i installed it and the car is still in limp mode. so far i have learned that the only thing that can cause a s5 to go into limp mode is a bad eomp or a fried ecu due to bad eomp. i have replaced the eomp and ecu and the car is still in limp mode. this is sooooo frustrating. idk what to do im about to sell it... any feedback will be appriciated. now i really feel left in the dust.

the issue may be that either eomp, either ECU,, or the common wiring loom is still faulty



go the rtek chip, from here it is the easiest cheapest solution to limp mode



if you still have issues after that,, then you ave a voltage issue at the injector,, or an earth issue in the device earths

both issues are usually fixed when you strip back the wiring loom up to two feet out from the cu plug

there is two earth bundles,, tied with a brass crimp,,, that require resolder,, and maybe adding a decent earth wire to and earth on the ecu case



there is also a power hub ( with its own crimp ) that could also possibly do with a reheat and resolder



there is reams of info about these common faults online ,, and if you havent tried this then you havent really tried yet