Ok, again just in case someone doesn't know I own the '79 with the '86 engine, ecu, and stock efi. Now my problem is that it is very hard to start, especially when it's cold; When it's hot it starts right up. Let me also through in that it might not be your usual problem since it's a bit of a franken-stein car, the fuel pump is wired like a stock 1st gen pump it comes on when the key is on. Pulling the fuse to the pump helps it to start sometimes, but not always, so does holding it floored; the funny thing is if you pull the fuse and hold it floored it will sound like it's going to start at first then nothing if you hold the starter nothing, but if you stop wait floor it again and hit the starter it will start after doing this like 4 times if you're lucky. If not you have to bump start; which sucks, the whole point of the efi would be so that it would start easier in any weather and it has seem to have gotten worse.



Thanks for any ideas



Also should I rewire the fuel pump through the opening circuit and afm like a stock 2nd gen??? Would that fix the problem

So the fuel pump runs when the key is in the ON position. It almost sounds like it's not running in the START position.



This is confusing though, 'cause those sound like "too much fuel" fixes.



I don't know about fix, but it would make it a little easier to diagnose I guess.



I wish I were better with electronics. Since the circuit opening relay is connected (powers?) to the ecu, is there a chance that the injectors aren't firing in the START position?

Exactly it sounds like too much fuel but, then hell I don't know??? I thought the pump shut off in the start position too...



I didn't consider that I'll have to find out, thanks

I wonder what the absence of the atmospheric pressure sensor would have anything to do with it? I thought I read in another thread that you don't have one.

I will get one asap, and see if that helps, I also think I need a new TPS, or readjusted anyways

i dont think the fuel pump running like a 79 would matter. the tps will affect it (a bit), vacuum leaks will also affect it, even tiny little ones. and last your atp sensor, when its unplugged the ecu prolly goes to some default value, if that is different than what you have in reality it will throw things off. the ecu might think you're half way up mount everest



mike

Thats what I think his problem is too.I still need one myself.I have a friend looking for one right now.'79Rx7 love the sig.So your using the SE fuel tank and lines then?You have a e-mail too. https://www.nopistons.com/forums/pub...IR#>/smile.png

Any progress?

it could be alot of things.... like leaking injectors, fouled plugs, low compression....etc My car has the same problem i have to floor it to start..... i think my injectors are leaking but not for sure.... the local parts store wants $300 can for an injector

it prolly vaccum leaks, and a misadjusted tps. we have 2-3 fc's that hot start with 120,000+ mile injectors, its vacuum leaks that make it flood



mike

Well you can eliminate leaking injectors RC Engineering just redid them, and plugs are like new only 800 miles, and definently not low compression.



It's starts fine when it's hot, It's when it's cold is the real problem

local performance stores like pep boys sell this spray called ether. spray it on certain places of ur engine where u think u have a vacumm leak. when the hose sucks up the ether, it shoots it out of the exhaust. this is how i found the vacuum leaks in my car when i got into an accident.



https://www.nopistons.com/forums/pub...IR#>/smile.png

Okay so everyone thinks it's a vacuum leak??? But I took everything apart and replaced ALL the vacuum lines and ALL the gaskets!!! So any ideas



I did replace the battery and tps, it seemed to turn over faster, but it flooded??? It always floods, I believe; because when it starts it smokes, also it seems to start just fine if i pull the fuse to the pump if it doesn't just start right up the first time.



Also it still idles funny, might these problems be related; and by funny I mean it jumps from 800 to 1200 until it's warmed up real good then it just idles at 1000 rpms

Does it push black smoke out the tail?

Now sorta whitish grayish blue??? but I also premix oil, and the omp is still hooked up

Then its not too rich.Did you test the compression on it?Hows the plugs?What about timing?Is it still good?

Compression test shows upper 7's (between 7.4-7.9) on all chambers on a factory mazda tester



The plugs still look new with only about 1000 miles on them



The timing is set two needle thicknesses advanced at about 850-900 rpm

if you wanna look for a vacume leak try a unlit proplane torch. when you kit the vacume leak the rpm will jump so then you kno wwhere the vacume leak is....







ej

i think yours will be much happier with that atp sensor



mike