hmmm... yeah might want to get those primaries test or replaced.

I think the sad fact is that trying to run big power numbers on pump gas is just asking for trouble on these engines. But I don't know... some folks always have great luck and others have very bad luck.

However the closer to stock the less problems in most cases.

 

Kevin sorry to hear your motor popped. Ihope you find the problem that thing was running good and i would hate to see you get rid of your car. This is Kerry from Starbucks i just bought a R2 red on black BPU & love it . Iwouldnt get rid of mine for anything worst case drop a new ls7 in there.

 

I know a guy who hauled fuel for several years, and he said that he delivered to many very big-name gas stations and from time to time, all of them instructed him to fill the premium holding tanks with the cheap stuff. He said it's sick, but there is no practical way to catch the store owners. Since piston engines don't have major problems, they figure it's a white lie.

I fill with only Sunoco 94 because I figure there's less chance of them pulling that kind of BS. However, if my engine ever pops, I'm going to immediately go back to the pump and have the octane tested by an independent lab.

Dave

 

How much boost aree you running again?? I must of missed that part. Why is everyone calling on water injection when he's running less than a 1bar of boost. I assumed Steve checked his duty cycles on the injectors. Water injection is great,but he doesn't need it if he's running low boost and in his safety margin. Thats just a bandaid, He needs to FIX the problem.

Keith

 

If you hadn't said this, I was going to. This is a BIG problem, since we (FD's) are so sensitive to detonation. The county I live in (Summit), IIRC, is the ONLY ONE IN OHIO that actually checks gasoline pumps to see if what's in them is what it's supposed to be! Just because you pay for premium, doesn't mean you will get it! I never buy anything but Sunoco ultra unless I have NO choice.

 

I use gas that lives in a sealed drum. Gotta love the VP C16

 

<<<3rd motor blown in 1 year >>>
Sorry to hear:-(

Obviously you have a problem somewhere in the car for 3 motors to let go with 14psi or less.
I highly doubt if its something in the ECU...I've seen Steve's maps and they are very safe. But the following could go bad and the ECU has no control.
-Fuel filter -> if over 40-50k miles on it, CHANGE IT ! location of the stock one is the main reason why it gets ignored. Aftermarket, change it anyway...they're cheap.
-fuel injectors-> are they the same inj's on all 3 motors? send them out and them cleaned. you mentioned 1600cc injs....they're huge and i've seen them flow over 5% from one to another.....most shops flow them and sell them as sets to avoid this problem.
-engine harness-> when you remove your engine go over your harness and check for broken wires and broken plugs...
-vacuum hoses-> inspect all and wire-tie all, mainly to map sensor and fuel pressure regulator.
-fuel pump-> I'm sure this has been changed...if its a MKIV pump, they don't like to see higher voltage from boost-a-pump gizmos. Walbro pump sit higher in the tank, therefore you cannot race the car with low fuel.

what are you using for boost control?
PowerFC has a over boost safety....if it goes past .25kg/cm2 over dialed boost(boost screen)it will shut down the injs.

Water injection is a band aid when you have any of the above issues.
Water injection should be used as a performance mod.....it does keep detonation away mainly when you run higher boost or even for the endurance racing where heat is the main enemy.

Hope this helps and you get to fix it.

Good Luck,
JD

 

^^^^^ Totally agree with JD,Couldn't say it any better.

 

Geesh.. Thanks for the boost of confidence! I am running the 12v relay to my walbro and always run 100 octane when playing hard. my afr are 11.0 or less. I know one hic-up and its over. I know what you are saying though. My buddy chunked a side seal @ 12000 w/ the hurleys. Didnt have his pump rigged up for voltage drop but who knows why it crapped. Just know it was a side seal on the rear rotor. How long you been running your latest motor w/ water injection?

 

i blew 4 engines in 8 months

it ended up being my fuel pump not flowing enough (old walbro with a clogged sock) so i got a new pump and clean sock and it was perfect

 

id bet this has nothing to do with the engines....its to systematic.

this is a sub-systems problem, like many have mentioned (f-pump, injectors, electrical, ecu...et...et)

 

I am by no means a FD tuning guru, but from everything I've seen your problem is probably attributed to some sensor or wiring issue. I'd bet that if you had a standalone ECU like a HALTECH installed with a fresh wiring harness (and cautiously tuned) when you got your first motor, you'd still be on that first motor.

Even though the fault probably didn't lie with the motors, you might want to get a reputable rebuild this time to be sure.

 

thanks for the input everyone, but unfortunately i dont have the money or time to do any of these things and i pay 500 a month for a car payment. who knows how long this will take to spend the money required to fix the prob. i really hope it's something simple like a primary imjector.

 

Sell out the other two junk motors and buy one, or salvage the good parts of each motor to make one and sell the extra good parts to help buy a seal kit. You have two LIM's,UIM,Turbo's Front,mid and end plates and housings. Trust me, it can be done.
BTW, that was just the two japspecs...What about the first motor?? wouldn't that make THREE motors...You better check out the forsale sections on the forum, Great deals are just a click away.

Keith

 

i got a full RA rebuild kit, with brand new rotor housings, good used endplates (all 3) eccentric shaft, front cover, 2 sets of stationary gears, new oil pump etc for about $2,300. That stuff would normally cost about $3,500 here not including the eccentric shaft, stationary gears oil pump etc etc. (im from the UK)

 

I'd recommend replacing the primaries rather than just having them sent off to be cleaned/bench tested. An injector on the way out can bench test fine, but act very differently when it's exposed to heat.

Given the costs and down time, it's cheap insurance.

 

If you can't afford to buy an engine at the drop of a hat, then you shouldn't own a 3rd gen.

 

Good Point............

 

umm i bought the other 2 motors and 2 days before the motor blew my tranny froze and i replaced that. if the tranny wouldnt have needed to be replaced i could almost afford a rebuild between the 2 motors that i have.

 

I was out in Vegas 2 weeks ago.. Saw only one 3rd gen parked at a convienence quick stop towards the north end of old vegas (on the strip). It was montego blue w/ bad paint. Know that dude?

 

Noob Question...
What exactly is water injection and what are the contributing factors that make it costly?

 

A simple search for "water injection" would have worked:

https://www.rx7club.com/forum/showth...3&page=1&pp=25
https://www.rx7club.com/showthread.p...ater+injection

 

Yea, I did try a a search, guess I didnt look hard enough or maybe I just dont know how to use the function right. Thanks anyways.

 

Sorry, wasnt trying to rain on your parade. I just have had many bad experiences in the past with the hurley apex seals. One positive, when they do break they do minimal damage to your internals.....this is the silver lining to the cloud i suppose. I think that running the 100 octane occasionally as you have mentioned is a great idea.

 

Unfurtonate but true. But in his defense it's 3 engines at the drop of a hat, not one. Don't forget that he ponied up for two already.