StinkyFatPig

ok so i had my injectors done and there flowin perfect and no leaking.. but my car still wont start..
It just turns over... and over and over.. then once in a while it will bump and try to start... then just back to the same old...

what could this be now? possibly a problem with the fuel pump.. maybe its not getting the fuel.. i just dont know anymore

niner

did you just guess that it was the injectors?

if you really want to fix it yourself you need to check lots of things. start w/ basics like fuel pressure, air intake leaks, ignition system, and compression. pull plugs to see if they are fouled, and make damn sure its not still flooded.

good luck
mike

seventhgear

niner is right listen to him ...

StinkyFatPig

the injectors where leaking.. i pulled plugs and they where soaked with gas after trying to start it..
and i when i got the report back from the injector shop both primary injectors where leaking...

plugs are good.. All plugs giving spark, I havent done a compresion test cause i dont have a tester.. I think i need to check that out.. I dont know what you mean by air intake leaks? like leaking from where?

I think im not getting fuel or not enough fuel or something.. so im going to have to try the fuel pressure.. possibly a pluged filter..

what else can i look into?

adamlewis

Did you unflood it since you got the new injectors in?

nashman69g

iTrader: (3)

I had the same problems ..went a week without my car ....finally i added a little oil to each housing and she woke back up.... take out i believe its the leading plugs and use a small hose to squirt a tablespoon of oil into each housing then turn motor by hand top help lube up rotor housing.... then give her a crank and she should start right up ---if not try new plugs and repeat... WHat tend to happen is the excess fuel builds up and removes the oil film of the housing causing a compression loss....Hope this helps !!

StinkyFatPig

so you saying just add alittle oil in the chambers and that should start it up? how does this work?

what what kinda oil.. like the whole ATF thing or normal motor oil?

hypntyz7

This adds weight to my theory (proven here often) that the flooding of rx7s is not a result of leaky/faulty injectors, but rather compression (or lack therof) itself. This is an example. I bet if he checks his compression reliably he will get a number below 95psi. For you doubters of my theory, think of it this way: almost every EFI import after roughly 1985 uses the same ND fuel injectors that our cars use, and you dont see them flooding all the time do you?

Cranking compression on rotaries is lower than on piston engines in most cases, new or otherwise. Cranking compression on a low compression rotary is really weak, which means that it'll take a few revolutions of your engine to build up sufficient compression. What happens in the meantime? Flooding. IT's not the injector's fault, its the engine's. This is why, when operated properly, a fuel cut switch works so well to prevent flooding. I give instructions on using one, that say to crank the car with the switch still off, then turn the switch ON while still cranking. This allows initial compression to build sufficient, *then* add fuel, and away you go. You let the fuel in too quick, and guess what, not enough compression to cause combustion.

Other examples: locally I rebuild many a 2nd gen, mainly s4's which are more prone to flooding anyway. I can take a car that flooded regularly, rebuild it, put it back together using the exact same injectors and such, break it in, and it will never flood again.

This is also why fresh rebuilds (with used rotor housings) flood regularly before and during breakin. These rebuilds are also somewhat low compression, same problem as above. The difference is, that unlike your old 100k+ mile engine which is slowly *losing* compression, your new rebuild is quickly *gaining* compression.

As for the specific problem in this thread, adding some motor oil or atf into the chambers will start the car, unless there are other problems caused by removal and installation of all those intake parts.

StinkyFatPig

that makes complete sence.. I think im going to go pick up a compresion tester tomorrow and try it out...

aswell im going to give the oil a try.. now, if this does work and gets the car to start what happends next time i try and start the car.. will it blow out on me again and have to repeat the process? or is this a somewhat permenant fix...

after that looks like the fuel cut switch is the way to go..

hypntyz7

Anyting under 100 is getting weak, but not gone by any means. Dont get bummed out over it, just know that the engine's days are numbered, usually 1year to 18 months. This is the case with 90% of the rx-7s on teh road today...

IT only works one time. Now, will it flood again? We dont know. It could have just flooded because of the extended downtime it had, you could have spilled fuel inside the engine when removing injectors, you could have had something off when you reinstalled it and tried to start it and since fixed that, etc. IF it floods again, youll have to unflood it again. It might not.

A lot of people like to bitch and whine and say that is just a band aid, etc. blah blah, but hell, for 5 bucks and 15 minutes, you cant beat it, cause it can buy you 1-2 years of trouble free operation of your car.

chrisrx7101

I had a fuel cut-off on my car when I bought it, the guy had put it in since he was having flooding problems. The process hypntyz7 described for using this switch is awesome... he's right.. works every time!!

I don't know about my compression, but I have never had my '87 flood on me yet, cause even if you flood it, you flip the switch let the engine turn just a bit, it may even burn the fuel in there and flick the switch again and your good to go.

Chris

NZConvertible

I don't think it's that cut and dry. An engine with clean (i.e. not leaky) injectors and low compression can flood. An engine with good compression and leaky injectors can flood. An engine with a mild case of both problems can flood. Plenty of people in that last category have cured flooding by taking the cheaper option and cleaning the injectors. Even if the low compression eventually catches up with you (and we know it will), clean injectors are a better option than a fuel cut switch, because an engine with clean injectors will always run better overall. That's why I always suggest cleaning the injectors first. As you correctly explain below, rotaries have lower compression at cranking than piston engines, so it makes sense that dirty injectors in a rotary are going to cause problems before the same injectors would in a piston engine. But what if the injectors are leaking? This would obviously cause the symptoms of low compression to start appearing earlier. An engine that's had quality fuel pumped through a regularly replaced fuel filter will probably have injectors that won't cause problems. But after ~15 years, an engine that hasn't been maintained as well could well have leaky injectors that combine with lower-than-ideal compression to cause flooding problems.

I'm not disagreeing with your (proven) low-compression theory, just pointing out that dirty injectors can and will be a contributor to flooding problems, and clean injectors are a lot cheaper than a rebuild and a good idea for a 15yo engine anyway.

akageals

My '87 continued to flood every time I tried a hot start, even after the injectors were cleaned. My car idled perfectly, got great mileage, started right up when cold, even started with a VERY nearly dead battery once. I don't think compression or injectors were my problem. I added a fuel cut switch and used it every time I started the engine. It ran perfectly for 2 years and is still going strong. In my case I had to hot start the car with the switch in the off position....car would fire right up, then turn the switch on and drive.

Todd