A buddy of mine totaled my '86 13b NA, and the engine was still good (we drove it home). I took my blown motor out of my other car, and put this one in, and now it won't run. It seems as though it is getting spark, but it won't accually fire. I replaced the stock injectors with the JDM T2 injectors for more gas flow. Now i do have the Bosch Platinum Laser-type plugs, so i figure they can handle the extra gas. I am using the stock computer from my old NA (the one the kid totaled). Any ideas why the motor wont run? I am getting gas out of the tailpipes, but my timing gun says that i am getting voltage through the ignition wires. I'm really baffled. The only other thing i did was remove the vacuum spider. I left the vacuum hose going from the upper intake to the lower, the oil metering lines, the purge valve, and the ACV. Any ideas would be GREATLY appreciated! I'm getting very frusterated with this...

 

I just had a similar problem with a new engine..... you have to do the ATF trick for it to work. I tried starting the car without doing it and nothing happened. the engine would rotate but it wouldnt start. once i did the ATF thing, the engine talked to me but still wouldnt start. then i realized that the power steering pulley was on too tight causing the eccentric shaft to not spin freely. once i loosened it, engine started right up

 

what is the ATF trick?

 

Do a search

 

i got the engine running pull starting it last night. i went up a small incline, and the car was running so bad that it wouldn't go over 20mph up this small hill. when i let off the gas petal, it backfired simetimes. i haven't messed with the timing since i took the motor out of my other car. Any ideas what could be cauing this?

 

You may be flooding it. N/A engines run rather rich to begin with, and then you went and increased the amount of gas being injected. I'm not sure how to reduce the gas flow without a fuel managment system. I'm sure someone else can chime in, though

 

i would suggest putting in some NGK's...those Bosch plygs really aren't designed for our cars!

 

I would go back to the 460 primaries and leave the 550 secondaries. I would check timing anyway... if you can get it to idle and i would definitly use some other plug other than the laser thing, since I don't know of anyone that uses them. Are you sure you got rid of all the vacume leaks? is the car an 86? or early 87? does it normaly operate on low impedence injectors or hi? That makes a big difference. At one point my car had one wrong injector, it made life hard. you might have a vacume leak but it sounds like a super leaky injector. I would just pull the EGI fuse, floor it, spin the starter for a while, let it rest/cool, then do it again. then put the fuse back in and start it. NO GAS until the motor is atleast doing like 400 rpms.

 

http://www.rx7.com/techarticles_unfloodFC.html

 

okay, i had fun tonight...i ran the car for about five minutes; no idling. i DID however get it going and it ran like **** again, it felt like the timing was horribly off. my air/fuel gauge showed a full rich bar. now, i was going up a hill, and at about 6 grand, i heard a pop, and it ran really good to the redline, then i shifted, and it did the same thing around 5 grand, then it didn't do it the rest of the drive. the motor is an '86 NA, i don't know what kind of injectors it uses. Both my wiring harness (if that makes a difference) and my computer is for an '87 NA. Would that make a difference? should i take the computer out of my other car (the one that matches the engine) and try it that way? I don't know if i mentioned this, but i removed the cat (the main cat), and just left the hose from the ACV disconnected instead of going to the split air pipe. Could this do anything? I think you guys are onto something with this hi or low impedence injectors (i don't know the difference). Thanks

 

Definitely try the matching ECU BEFORE you do any more damage...matching injectors, too...

 

In the middle of 1987 MAZDA switched from low impedeance injectors to high. You have to find out if both cars match... pre-1987.5 (low imp.) or after 1987.5 (high imp.) Then take it from there, making sure you don't have mix and match... for ex: pre-87.5 injectors with a after-87.5 ecu, harness, resistor pack. That'll make a difference if it's mixed up and you used parts from both cars. There's a ceramic resistor pack on the passanger side fender/shocktower that can identify pre-87.5 low impedence set-up.

 

i think the injectors are your problem. make sure your injectors and ecu match up (like wayne said) before you go any further. na's even run rich with the 450's. why put 550's in there?

 

i changed the injectors and the same thing happened. both cars had the pack infront of the left strut. anyone have any idea why my car worked for a couple of seconds? someone suggested some kind of grounding problem or a short in my coil. it seems like it isn't firing correctly or in the right order, but i double and triple checked the ignition wires and they are good, and again, i haven't touched the timing since i tookt he motor out of the other car...oh and by the way, the computer that i took out of my other car is exactly the same number as the one i was trying to use.

 

not to jack the subject of this thread, but if I am making as much horsepower as a TII would I not need to supply the motor with as much fuel as a TII on the top end where I am making the horsepower? I.E. TII secondaries and Fuel pump? If the 460s are sufficient, why are people with ported manifolds and headers using the higher flowing injectors? That is why I said 550 secondaries. I am going to try them.

 

you're making as much power as a stock TII. TII injectors flow enough for like 240whp.

go ahead and try them but you're going to be running too rich unless you have some other means of leaning them out.

 

SAFCs are pretty cheap and I will probably end up with one of those as well. How about the 460s? what is the upper limit of horsepower and RPM for those at less then 100% duty cycle? What is the hot FI setup for stock ports?