Breakup...help!

[bmatharu]

Just posted this over on FDUK:

I\'d really appreciate any insight on this - pinged an email over to Carl this evening as well.

Hi guys,

I\'m at a bit of a loss with this one, and could really use some input from some experienced minds.

For those of you who I haven\'t had the pleasure of talking to or meeting, I am a 22 year old student who pours all of his money into his FD at any given point in time lol. However I have very little of said money to afford spending any amount on something that might not fix the issue, hence this thread rather than a more trial and error approach - I need to get to the bottom of this quickly and effectively.

My car is still on twins, mods include front mount intercooler, apexi rad, apexi twin filters, hayward street port with around 8k on it since the rebuild last Dec, power FC, HKS d/p, resonated midpipe, titanium backbox, optima blue top battery.

The car was rebuilt when I bought it. After the rebuild I ran the car in and when I went back for the full map there was a problem with a misfire. I was advised to grab a twinpower, which I did, and it didn\'t really fix the problem. The blatent misfire was mostly gone, which was really like being pulled back by a truck at WOT, particularly around 4/5k rpm. But I still had significant break up, little to no power past 4k rpm unless I pushed through to around 6.5/7k at which point the power picks up again. Then the regulator on my alternator went and I had 15.9V reading on the Commander, and when I put my foot down the car felt like it was on steroids. No break up whatsoever and it was far quicker than I have experienced at any other point before or since. Needless to say I took the car straight home til I could get another alternator. After changing the alternator it was back to the normal crappy state. I went back to Hayward and the guys had a look, checked the fuel pump wiring which seemed to be ok and I think had a little fiddle with the ignition wiring and went out to map the car, and came back saying it was fine. I think Magnecor KV85s were also fitted. Plugs and oil were changed, and for a little while the car was ok with no break up, albeit not as powerful as when the alternator went. Short while after, couple weeks, it was back to breaking up. It\'s been the same since. I don\'t know what the state is with the wiring to fuel pump and ignition (first FD and not much experience of meddling with cars, although I have tried to do everything that I can myself on my FD in the interest of learning!), although Carl did say the ignition had been \'beefed up\' - I dont know exactly what was done.

I know there are relay rewires that can be done to the ignition and fuel pump, but what I would like from you guys is a bit of input as to what you think might be causing this and what I should be doing next? If a rewire then recommendations on wires and other parts would be great. Hopefully Carl can pop along and provide some more info on the situation. Ideally I would have liked to take another trip up to Haywards or even chat to Carl about the latest developments, as I havent touched base with him since the problem has returned - unfortunately time is at a premium for me at the moment and I figured the forum is the best place to get all the info together in an efficient way.

Cheers!

Bally

[davehg]

is it on a standard ECU as with the mods you have i would say you need an Apexi for sure

[L18M]

maybe try a different pfc if possible? they sometimes can cause problems even its works fine at some rev range.

change coils?
make sure the magnecore leads are fit snug (but not too snug to the coil) else if the rubber onthe leads are too tight then it can cuse the leads to slide off the coil. (mine does that so been cable tied tight to the coil)

not sure about rx7 but on scooby a faulty o2 sensor can cause loss of power at certain rev range.

cheap things to try. HTH

[TRIND-FD]

Check earths, fuel filter,

[trotter]

checked all the vac hoses? Any issues appearing around the 4k mark tend to set off rats nest alarm bells in my head.

graeme

[Eoiny555]

Just posted this over on FDUK:

I\'d really appreciate any insight on this - pinged an email over to Carl this evening as well.

Hi guys,

I\'m at a bit of a loss with this one, and could really use some input from some experienced minds.

For those of you who I haven\'t had the pleasure of talking to or meeting, I am a 22 year old student who pours all of his money into his FD at any given point in time lol. However I have very little of said money to afford spending any amount on something that might not fix the issue, hence this thread rather than a more trial and error approach - I need to get to the bottom of this quickly and effectively.

My car is still on twins, mods include front mount intercooler, apexi rad, apexi twin filters, hayward street port with around 8k on it since the rebuild last Dec, power FC, HKS d/p, resonated midpipe, titanium backbox, optima blue top battery.

The car was rebuilt when I bought it. After the rebuild I ran the car in and when I went back for the full map there was a problem with a misfire. I was advised to grab a twinpower, which I did, and it didn\'t really fix the problem. The blatent misfire was mostly gone, which was really like being pulled back by a truck at WOT, particularly around 4/5k rpm. But I still had significant break up, little to no power past 4k rpm unless I pushed through to around 6.5/7k at which point the power picks up again. Then the regulator on my alternator went and I had 15.9V reading on the Commander, and when I put my foot down the car felt like it was on steroids. No break up whatsoever and it was far quicker than I have experienced at any other point before or since. Needless to say I took the car straight home til I could get another alternator. After changing the alternator it was back to the normal crappy state. I went back to Hayward and the guys had a look, checked the fuel pump wiring which seemed to be ok and I think had a little fiddle with the ignition wiring and went out to map the car, and came back saying it was fine. I think Magnecor KV85s were also fitted. Plugs and oil were changed, and for a little while the car was ok with no break up, albeit not as powerful as when the alternator went. Short while after, couple weeks, it was back to breaking up. It\'s been the same since. I don\'t know what the state is with the wiring to fuel pump and ignition (first FD and not much experience of meddling with cars, although I have tried to do everything that I can myself on my FD in the interest of learning!), although Carl did say the ignition had been \'beefed up\' - I dont know exactly what was done.

I know there are relay rewires that can be done to the ignition and fuel pump, but what I would like from you guys is a bit of input as to what you think might be causing this and what I should be doing next? If a rewire then recommendations on wires and other parts would be great. Hopefully Carl can pop along and provide some more info on the situation. Ideally I would have liked to take another trip up to Haywards or even chat to Carl about the latest developments, as I havent touched base with him since the problem has returned - unfortunately time is at a premium for me at the moment and I figured the forum is the best place to get all the info together in an efficient way.

Cheers!

Bally

Did you ever get this sorted?

[boosted]

.....Also have you got alarm and immobilizer fitted? Mine was suffering with mild break up and it was the ignition immobilizer relay in the alarm...Relays are a lot smaller...and if its been on there a while contacts could be/ dirty/ burnt.

[Eoiny555]

I had a simmilar problem to this, did a bit of looking around last night & found that the white plastic bit on the leading spark plug on my front rotor had cracked, switched it for another one i had in the garage & went for a spin there & it seems to have resolved the issue although i now seem to have a boost leak on the secondary turbo