My FC is chugging along (not good)

[djmtsu]

On the way to DGRR my FC began to miss a little, then the exhaust started to sound weird and it was losing power. We tore out the plugs and did a poor mans compression test. Both rotors sounded strong. Checked coolant and oil, neither are intermixed. Checked spark and its all good. Even put new plugs in.

I was getting a CEL flicker when it started acting up. And I get boost (although the needle is shaky). A few people at DGRR said to look into fuel issues. So before I go this weekend to attempt a resurrection, I would like some input.

S5 TII, no emissions, stock ECU with an FCD. Full exhaust, FD pump.

Here is a vid:

MkH7H5mRQfg&hl=en&fs=1&rel=0

[vex]

your running on one rotor it sounds like. I'd check the rear housing to see what's going on there.

[Phoenix7]

:( sorry man that sounds horrible....compression check?

[IH8DSM]

if it was fuel i wouldnt think it would run at all, or at least idle then die. If it was a intake or exhaust gasket it would run like crap or not at all. Ive never experienced a down rotor so im not sure on that one.

[Rx-7fetish]

your running on one rotor it sounds like.

Ditto. Just because both rotors have good compression does not mean that both are getting fuel right. Having good compression, and the sound of that video i would say you have wiring or fuel issues killing one of your rotors. I would still try to get some real compression numbers though.

[Rx-7fetish]

if it was fuel i wouldnt think it would run at all, or at least idle then die. If it was a intake or exhaust gasket it would run like crap or not at all. Ive never experienced a down rotor so im not sure on that one.

A wiring issue could cause one of the rotors injectors to act up, or bad injectors, or clogged, and so on and so on. Checked for vacuum leaks??

[Whizbang]

The needle for the boost gauge *shouldn't* be shakey either. That would imply some sort of possible electrical issue. Might not be the direct cause of whats happening. Could just be something else.

Have you confirmed timing? Also, get your hands on a piston compression tester, have someone crank the car and hold the shreader valve open so you can watch the faces.

[djmtsu]

When I free rev it, the boost gauge pulls down vacuum pretty hard. When I try to drive, it will go into boost, put the engine misses and sputters so the boost is shaky.

It is getting spark (ask Paul....he knows). I am hoping it is something simple, but I will not know until this weekend when I can get back to it. I plan on bringing a compression gauge along as well. I don't think it is *blown* since I have experience with a blown engine.

[My5ABaby]

I'm not sure I believe it's getting spark. I think we need a video of Paul testing it. :reddevil:

[Boostmaniac]

That horrible hammering sound, god that sounds nasty. Obviously related to engine speed.

I got nothing on this one that would be deemed "good news".

[djmtsu]

Anyone think it threw a bearing?

I plan to bring a set of coils, injectors, test the wiring, compression (with a tester).

Another idea Kevin had was maybe it knocked and chewed up the corner seals.

[djmtsu]

Fuckit. Towing it home this weekend. Reservation has been made. I am not going to try to do a driveway repair on my baby.

[FerociousP]

Fuckit. Towing it home this weekend. Reservation has been made. I am not going to try to do a driveway repair on my baby.

so you are going to tow it home and repair it in your own driveway?? lol

I'm not testing for spark again. :o11:

[djmtsu]

so you are going to tow it home and repair it in your own driveway??

Garage bitch.

[Rx-7fetish]

garage huh? well arent you special, ive been laying out in the mud for the past 2 days working on mine lol. seriously though good luck and i hope its something simple.

[vex]

I say it's a mouse that got sucked in.

[rx4ur7]

Afraid it sounds like a bearing, rear.

[djmtsu]

My next question is, how the hell would a bearing fail with only about 16K on the engine? And the oil checked and changed religiously?

Also why am I getting great oil pressure? Wouldn't bearing failure read low pressure? Or no pressure?

That sucks, because if it is a bearing that is going to be alot more expensive to rebuild than I had planned.

[rx4ur7]

Bad install, bad bearing to start with. Blocked oil passage. Anything is possible.

Yes oil pressure should usually give you some indication.

If turbo isn't coming apart not much more that can cause that kind of noise. Fuel delivery or ignition issues usually don't sound like a bad rod. Could be quality of sound on vid but sure sounds like metal on my computer.

Air pumps can make really nasty noises especially when they shuck a seal. Parts get stuck in the ACV and cause rough running. Partially blocked exhaust will cause lack of top end power, but you would notice higher water temps when run for any length of time.

If you can get a hold of the old tape compression tester to use it gives you much better read out for diagnostic.

[djmtsu]

Bad install, bad bearing to start with. Blocked oil passage. Anything is possible.

Don't think that is it. I stand behind the company that built my engine, and it has ran FLAWLESS until now.


Yes oil pressure should usually give you some indication.


And my Oil Pressure is spot on.


If turbo isn't coming apart not much more that can cause that kind of noise. Fuel delivery or ignition issues usually don't sound like a bad rod. Could be quality of sound on vid but sure sounds like metal on my computer.


I am thinking that clunking is something else, like something banging because the engine is shaking so much. It isn't that loud in person. I might need to look into some new motor mounts. LOL.


Air pumps can make really nasty noises especially when they shuck a seal. Parts get stuck in the ACV and cause rough running. Partially blocked exhaust will cause lack of top end power, but you would notice higher water temps when run for any length of time.

No air pump, infact I have never had one on this car.


If you can get a hold of the old tape compression tester to use it gives you much better read out for diagnostic.

When I bring it home, I will look into it more. Starting with replacing the coils, and checking the injectors harness, and the injectors themselves.

The only good thing is, if it is toast I will make it better next time.

[My5ABaby]

Check your PMs DJ. :icon_tup:

[TehMonkay]

Check your electrical connectors on the injectors and make sure theyre not damaged, all of them get 12v with ignition on, and if you can see if the ecu is opening them when you try and start the car. As long as you are getting spark to both leading plugs i'd say it's fuel.

[djmtsu]

I think I found out what the 'hammering' sound is. The AFM and air filter are not securely mounted anymore, and the end of the filter was knocking against the inner fender. When we I fired it up to move it onto the trailer, I held my hand on it and that sound went away.

Whew.

[NoDOHC]

Keep us posted, I hope nothing major is wrong.

[Mobius]

Since the AFM wasn't set securely, and was banging around like my ex, then would it not make sense to check/replace the AFM to ensure it's working properly?

[djmtsu]

Finally got around to compression test yesterday.

All good on both rotors. Spark is good, so its time to pull manifold and check injectors.

[josh18_2k]

v8 time! :willy_nilly:

[Whizbang]

hammer time?

[Phoenix7]

v8 time! :willy_nilly::cuss: and your car looks :icon_tup::icon_tup::icon_tup::icon_tup: in black.

[Phoenix7]

Since the AFM wasn't set securely, and was banging around like my ex, then would it not make sense to check/replace the AFM to ensure it's working properly?+1

used injectors? How many miles?

[djmtsu]

The injectors were in the engine when I bought the swap from Landers. I have access to new injectors at work (for cheap) so I might pick up a set.

I am going to borrow an AFM and see if that does anything. We will see. I was too busy today fixing the Jeep, so I will get to it this week when the wife is out of town.

V8? Pfft, that's for sell outs! :rofl:

[TitaniumTT]

If the car sat for a long periord of time my guess would be injectors. I've heard and been witness to cars that sat for months and the moisture that is inherent with todays soup they call gas sits in the injectors and corrodes them to the point of sticking. When cut open the corrosion looks like cocaine.

[Whizbang]

injectors do have some small parts in there. Doesnt have much room for foreign material. Hell rebuilt injectors really cant even sit too long before you can start seeing issues with them sticking.

[djmtsu]

All true. And after it sat all winter under the cover, condensation was trapped under it, and there was surface corrosion on some of the underhood bits. Like the turbo compressor housing, water pump housing, bov mount.

That is why I think something got corroded in the harness, and is keeping the injectors from firing, or the injectors themselves are to blame.

We will see. Thanks for the input guys!

[rx7 FC TII]

im having a very similar issue. im kinda stumped on what it is right now. it could be the AFM. thats what im thinking at this point.

does the crank angle do anything after start up? ive had a problem with that wire being loose on start up.

[classicauto]

If the car sat for a long periord of time my guess would be injectors. I've heard and been witness to cars that sat for months and the moisture that is inherent with todays soup they call gas sits in the injectors and corrodes them to the point of sticking. When cut open the corrosion looks like cocaine.

"Want to Buy:

old rotten injectors. Must be very corroded.
only pure columbian corrosion accepted
i'll pay whatever you want. Even BJ's"

[Whizbang]

im having a very similar issue. im kinda stumped on what it is right now. it could be the AFM. thats what im thinking at this point.

does the crank angle do anything after start up? ive had a problem with that wire being loose on start up.

yea it does quite a bit after start up.

[djmtsu]

"Want to Buy:

old rotten injectors. Must be very corroded.
only pure columbian corrosion accepted
i'll pay whatever you want. Even BJ's"

[Bob Saget]I've sucked dick for used injectors[/Bob Saget]

[IH8DSM]

So do I get to help tear apart a turbo motor?

[TitaniumTT]

"Want to Buy:

old rotten injectors. Must be very corroded.
only pure columbian corrosion accepted
i'll pay whatever you want. Even BJ's"

:rofl:

Hell man, pull your filler apart and if it's anything like mine you'll find plenty of it behind the flapper door. If you get creative you can figure out a way to extract it from the filter. That's where it always seems to land.

[djmtsu]

S5....no flapper, just a bullet plunger!

[FC3S Murray]

Fiveomotorsport.com

Good injectors for a cheap price. Siemen Dekas, Bosch, ect

They sell FC rx-7 specific milled injectors too!

[djmtsu]

Fiveomotorsport.com

Good injectors for a cheap price. Siemen Dekas, Bosch, ect

They sell FC rx-7 specific milled injectors too!

Pretty sure I can get stock injectors cheaper than anyone here ;) But, if it is injectors, I am getting 750cc's and an Rtek.

A quick question:

If it is the AFM, shouldn't the check engine light be on when the car is running? Because it is NOT.

[djmtsu]

Welcome back thread.

I need to get this thing running ASAP. I found something else, and I would like to get the most money out of it as possible. Or if that deal falls through, it needs to be tip top for DGRRX.

So, here is what I am going to do in order. Compression test is done, and its all good.
-replace AFM
-replace injectors
-replace harness
-replace ECU

While the UIM is off, I will inspect the LIM gasket and the o-rings a such on the injectors.

Everyone cross their fingers.

[Max777]

you can test an afm for resistance. You can also do a test on the injectors you keep to check that they are witin specs.(requires injectors testor, not sure where to get it) I'm sure that you are aware of this, but some places like corksport do electrical harness rebuilds, althrough it's pricey. If you do end up going with this option, may I suggest the 2.0 rtek, or perhaps an Apexi power FC with banzai link connector? I think that this is simply worth its weight in gold if you need/want to replace your ecu anyway. It should (dont quote me) work like stock, and give you a lot more control of the engine.

Used Power FC's can be picked up for roughly the price of a new megasquirt unit, or you can go with a full standalone like a haltec in which case the harness would come with it. Seeing as how some sell for around 600, and a rebuilt hanress is around 800? that seems like a deal to me. Opinions?

[djmtsu]

Yeah I could test all of it, but I already have a harness and injectors. I am borrowing FerociousP's AFM and ECU to test that aspect.

If the ECU is dead, I will pick up some sort of EMS replacement. Whatever I can get a good deal on.