Rx7 flooding or cracked seal
05-05-23, 08:57 AM
#1
Junior Member
Thread Starter
Rx7 flooding or cracked seal
Hello all, I need help on my 1995 rx7 fd.
Very sorry if there was already a post with same issue but I tried searching for a similar post to my problem but had no luck for around a year now.
my Rx7 is with stock turbos and running on pfc ( unfortunately I don’t have commander )
The car was working perfect but once in a while the car would hit boost cut on 3rd gear which if I know correctly the pfc would cut fuel.
one fine day the car hit boost cut and it turned off right after but started back up immediately.
From then on the car is acting up on idle and low rpm but as soon as I go to 4k the car works perfect and pulls as used to and starts on cold and hot each time but heat light is flashing and couldn’t count how many flashes to be honest.
Now I know that the pfc uses the heat light either for knock or as injector duty and we were thinking that an injector got stuck open because the car makes a huge amount of fuel smell on idle and backing when clearing up + oil dip stick drips fuel after a new oil change.
I have done a compression test and rear came out all 90’s but front came as 81, 54, 48.
Now my question is and sorry if it’s stupid… Could it be the low compression is due to flooding or it is definitely a cracked seal?
if it is a cracked seal I thought boost cut is made to save engine not break it..
looking forward for anyone’s help please.
Very sorry if there was already a post with same issue but I tried searching for a similar post to my problem but had no luck for around a year now.
my Rx7 is with stock turbos and running on pfc ( unfortunately I don’t have commander )
The car was working perfect but once in a while the car would hit boost cut on 3rd gear which if I know correctly the pfc would cut fuel.
one fine day the car hit boost cut and it turned off right after but started back up immediately.
From then on the car is acting up on idle and low rpm but as soon as I go to 4k the car works perfect and pulls as used to and starts on cold and hot each time but heat light is flashing and couldn’t count how many flashes to be honest.
Now I know that the pfc uses the heat light either for knock or as injector duty and we were thinking that an injector got stuck open because the car makes a huge amount of fuel smell on idle and backing when clearing up + oil dip stick drips fuel after a new oil change.
I have done a compression test and rear came out all 90’s but front came as 81, 54, 48.
Now my question is and sorry if it’s stupid… Could it be the low compression is due to flooding or it is definitely a cracked seal?
if it is a cracked seal I thought boost cut is made to save engine not break it..
looking forward for anyone’s help please.
05-05-23, 01:23 PM
#2
welcome to the board. 
while it is possible for you to "wash away" some compression, i don't think that's what you're dealing with here. for me, the tell-tale sign that the engine is hurt, is the fact that rotor 1 has one high number and two low numbers - indicative of a likely dead apex seal. if all the numbers were in the 80s, then it would seem a little more promising, but unfortunately that's not the case. i suppose it's possible that you may have some stuck side and/or corner seals that correspond with the compression pattern, and if that's the case, then you may have some luck trying to dissolve some of the carbon that would be causing them to stick. it's worth a shot, but i wouldn't tell you to hinge all your hopes on it.
that said, i'm not qualified to answer your questions about the Power FC so you may want to wait until someone that has experience with them chimes in with a more comprehensive opinion. my response is limited to the poor idle, flooding and the compression numbers you posted.
while it is possible for you to "wash away" some compression, i don't think that's what you're dealing with here. for me, the tell-tale sign that the engine is hurt, is the fact that rotor 1 has one high number and two low numbers - indicative of a likely dead apex seal. if all the numbers were in the 80s, then it would seem a little more promising, but unfortunately that's not the case. i suppose it's possible that you may have some stuck side and/or corner seals that correspond with the compression pattern, and if that's the case, then you may have some luck trying to dissolve some of the carbon that would be causing them to stick. it's worth a shot, but i wouldn't tell you to hinge all your hopes on it.
that said, i'm not qualified to answer your questions about the Power FC so you may want to wait until someone that has experience with them chimes in with a more comprehensive opinion. my response is limited to the poor idle, flooding and the compression numbers you posted.
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Mrm091 (05-05-23)
05-05-23, 01:57 PM
#3
Junior Member
Thread Starter
welcome to the board.
while it is possible for you to "wash away" some compression, i don't think that's what you're dealing with here. for me, the tell-tale sign that the engine is hurt, is the fact that rotor 1 has one high number and two low numbers - indicative of a likely dead apex seal. if all the numbers were in the 80s, then it would seem a little more promising, but unfortunately that's not the case. i suppose it's possible that you may have some stuck side and/or corner seals that correspond with the compression pattern, and if that's the case, then you may have some luck trying to dissolve some of the carbon that would be causing them to stick. it's worth a shot, but i wouldn't tell you to hinge all your hopes on it.
that said, i'm not qualified to answer your questions about the Power FC so you may want to wait until someone that has experience with them chimes in with a more comprehensive opinion. my response is limited to the poor idle, flooding and the compression numbers you posted.
while it is possible for you to "wash away" some compression, i don't think that's what you're dealing with here. for me, the tell-tale sign that the engine is hurt, is the fact that rotor 1 has one high number and two low numbers - indicative of a likely dead apex seal. if all the numbers were in the 80s, then it would seem a little more promising, but unfortunately that's not the case. i suppose it's possible that you may have some stuck side and/or corner seals that correspond with the compression pattern, and if that's the case, then you may have some luck trying to dissolve some of the carbon that would be causing them to stick. it's worth a shot, but i wouldn't tell you to hinge all your hopes on it.
that said, i'm not qualified to answer your questions about the Power FC so you may want to wait until someone that has experience with them chimes in with a more comprehensive opinion. my response is limited to the poor idle, flooding and the compression numbers you posted.
I think that the engine is hurt as well.
I did try the ATF trick and removed plugs to remove excess fuel and had 6 wooshes, and it did get better for a moment but then when it’s cold it’s seems that it’s struggling on one rotor even though it fires up on first try.
Once the engine is warm it holds idle but till it gets up to 3 to 4k you can hear the engine is not right and a bad fuel smell, after 4k rpm all good.
Most probably that when I had the boost cut the car went lean on boost so bye bye front rotor 😞.
Hoping that someone can tell me if the fuel cut happens on just one rotor or on both, cause I did have one person telling me that the pfc cuts the fuel on the rear rotor but I honestly don’t know.
Reason I wrote this post because yesterday I decided to crank the engine after some months and the battery was almost dead and funny enough the car still fired up with the starter burley had power to turn the engine.
Last edited by Mrm091; 05-05-23 at 02:01 PM.
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