hellspcangel911

Hey guys,
Let me start off by sayi ng that i searched for hours for an answer.

I got a 87 NA base, and it wont start, the car sat for 3 years, before that it ran fine. I installed a new fuel pump, works fine (jumped the green connector pins by the air box, works, good fuel pressure at the rail), I cranked it over and the it didnt start so I pulled the plugs out, cleaned them up (they are NGKs as stated int he service manual) and let the car sit overnight with the plugs out. I checked all the plug wires for good contact and no corrosion, the car has good compression, all within spec, the start cranks over fine, I have a truck battery located in the rear of the car and I use the 50amp start function on my battery charger when cranking.
I checked the plugs against the block for a spark, and no jumping sparks. I took out the air filter, got a new air meter...
put the plugs back in today, cranked her over for 15 seconds, no start. I would push start the car... but if it doesnt start Im not able to push it back up the hill on which I live.

Please, HELP>


Thanks
gtm

2slow4stock

iTrader: (18)

Are you sure your dumping fuel into the engine then? Flood the engine on purpose, and see if you are, If not then your MAF might not be hooked up right then since you said you bought a new one. Well all a engine basicly needs is spark, fuel, and air. So you say you have spark but no start? Are you sure you didn't put the fuel pump on backwards? I dunno how its possiable to put it on backwards but recheck.

hellspcangel911

thanks for your response.
the fuel pump is definetly installed properly. see the pic. besides then i wouldnt have the fuel pressure

i will check the injectors now per manual but i dont think thats it.

any ideas, come on guys you are all genius!

2slow4stock

iTrader: (18)

Try this, get a can of starter fluid spray, and spray into the intake then crank the car if the car catches. then you know it will start so give popping the clutch a chance if it does catches.

hellspcangel911

thanks for the info. I will try that tmrw ( i am all out of starting fluid)

So I gave it one last crank, and I went to go look at the engine make sure its not on fire..lol, well i get back in the car and notice a strange smell, like a fried circuit board... I look down at the ECU (all the carpets and stuff are taken out of the car) and theres this little drag of smoke exiting the ecu.... fck.

I take the thing out and apart, one of the resistors is burned and melted into the component next to it, I'll post pics tonight... I hate my life....

Now aside from dishing out the cash i dont have to get one, i have to figure out what caused it.

Thanks guys

Tech_Greek

Also,

You state no jumping sparks, they should very well be jumping if they are close to being grounded out.

However, if the ECU is gizzone it won't do any good to fire off the spark plugs if it can't tell what it is doing!

- Tech

seto kaiba

if you still havent gotin it started i had a similar problem a few time what i did was pull all 4 plugs give them a good cleaning, then befor you put them back in crank the motor over a few times to let it blow out any possible fuel flooding then replace the plugs, if that dont work check your mass air flow sensor its possible that over the 3 years it has set that the wiring my have shorted out or the thing has been corroded shut and wont give the motor the air it needs to fire correctly,
if that isnt the issue change the fuel filter and check your fuel lined you might have a blocage some where in your main fuel line thats not allowing it to go to your injectors. you just have to keep with it, good luck and hope it helps, if not let me know ill try and help out.

seto kaiba

ya that would do it that aint no good well once you get it replaced let us know if you can start it from there

hellspcangel911

thanks guys for all the help.

The injectors are getting fuel, positive about that
the mass air flow sensor workd on the previous car, and all the contacts are good.

I had the plugs out and cleaned them with a wire brush, carb cleaner and then blew them out with my compressor. a nice sold spark on all 4 plugs.

Im trying to get a new ECU, then I will repost


thanks a bunch!!

Sideways7

iTrader: (7)

Check out junk yards for ecu's. If you can find a good u-pull place, then the ecu shouldn't be too much. I could prob fix the ecu if I had the right tools, but I don't.
Also, you want the sparks to jump. I bet the problem is related to the truck battery you are using.

tIIsleeper

You should also check the crank angle sensor for the proper resistance and to see if it is hooked up.

hellspcangel911

Il check out that crank sensor, good idea.

I dont see why the truck battery would be an issue, its the same one as in my S6 Audi and 03 M5. I could fix the ECU if I was sure its just those visible parts that are burnt because its not worth testing each component for 30 bucks.

I just picked up a ECU for under 30 shipped. Theres a few good u-pull places here, none have RXers.

Now I just need to find out what fcked up the ECU...
I'll keep you posted

Sideways7

iTrader: (7)

How long had you been using the battery in this car before the problem started? I guess that if you have used the battery before, its prob no tthe problem. I just figured it was one of those "I had this battery laying around and thought it would work" kinda things.
Yeah, 30 bucks isnt bad. I am fortunate to have several rx-7s in the junk yards around. Unfortunately, most of them know how hard it is to find them so they jack up prices and the other ones are all picked over.

hellspcangel911

yea, i like buying from you guys alot better than junk yards... it seems to work better, cost less and be more civilized.

it was one of those "i got this battery lying round...il make it fit" but the starter cranks it well and i get a good spark.. if you really think that its a problem i can take the batery out of my probe gt.

thanks

buttsjim

If your car was sitting for 3 years, your injectors are probably gummed up and not spraying fuel. I suggest checking and cleaning them.

That wouldn't explain your fried ECU, though.

Edit: I read that you know they're "getting" fuel. But, are they spraying it?

HAILERS

The Fuel Pump Check Connector is not GREEN.

harley71105

YOu might also check the two shielded connectors on the wires coming out of the CAS. One is right there by the CAS and the other looks just like it and is under the brake master cylinder. I had gotten brake fluid in mine over time and it caused an intermittent no start that took me 3 years to figure out. Clean those conncectors inside and outside with an aerosol electronics cleaner (most auto parts stores carry this). A used ECU should be under $100.
Also, check all the wiring you can for ground faults and chafing. Hopefully you don't have something shorting out somewhere sending some bad voltage to the ECU. Good Luck !

DragonRx7

Another simple thing that I overlooked for quite a while is, check you fuel filter. You might be getting some fule through the injectors but the filter might be restricting the majority of it.

prjct87rx7

iTrader: (7)

just get new plugs 10-1 it fires up...same thing happened to me after replacing everything..i finally replaced my plugs that only had 1,100 miles and she started right up

hellspcangel911

It has all NGK-R plugs in it now, what do you reccomend? (i went to autozone and they dont have any) But I might as well swap those out.

Clean the injectors, Good idea. I will go do that now.


Like I said I have the entire car's enterior taken out and there are no signs of bad wires, chapping, broken connector or oxidation/curroison in the wires.
The only thing I noticed was that the split air soleniod sensor had the insulation on the two wires melted off, perhaps that could have done it?

Clarification: The wire connector (white) with TWO wires is the one that you jump to test the fuel pump.
and the one bearing three wires (green) is the one that you use to test the TPS.

GREEN: 2 blue/red wires, 2 blue/yellow wires, and one black/white wire
White: Black/blue and brown

Im starting to get worried that when my friend was helping me last night and I told him to jump the green connector he did, maybe that fried the ecu... i hope the TPS is ok.... crap.

buttsjim

Try and check your primary injectors before cleaning them, because that way you can confirm whether or not they were the cause of your no-start problem. Then clean them.

inflatablepets

You know you have to have fuel, compression air and spark. You need a systematic approach to troubleshooting. Compression being the first issue. Find out if the compression is good. Find out if the ignition system is working properly. Then find out if the fuel system is working.

jhammons01

The plugs should have been the first thing you tried. My experience with plugs from two strokes (similar to our motor burning rotories) is that they foul when they want to....and that is often.

jhammons01

Also, once a plug fouls it really hard to get it to fire correctly if at all. cost of doing business.

prjct87rx7

iTrader: (7)

and you cant get our plugs at autozone try an import place