Still cant Rx7 to start PLEAAASE HELLP
 

Ok ive been trouble shooting my 87 Tii for over a month. I have spark, i have fuel, i have air. It turns over but doesnt even act like it wants to start.

HISTORY: I pulled the motor to paint the engine bay. I figured 2 days tops so I didnt bother labeling the the harness (bad idea i knew better). ended up being over month and a half before i could get it back in the car due to one thing or another. While the motor was out i did the rats nest removal. blocked off emmisions, painted the engine bay and i think thats it. I did have some issues finding where some of the plugs went to but i think i got them all worked out now. Car will not start. it did run prior to pulling motor. Any Ideas where to start? I would greatly appreciate help on this for i miss driving my car. (ive been stuck driving my STI hehe) but i really miss the rotory. thanks

AFM plugged in?

yup and tested it as well just to make sure it was good

Did you unplug the harness from the ecu? Maybe you missed a plug somewhere.

yes when i pulled the motor i unplugged ecu and pulled harness and motor at same time. i believe there are 4 plugs that i had to unplug under the dash which i did plug back in. but just for grins ill go double check them now.

Did you check fuel going into the rails or coming out the injectors?
Check your timing. Especially if you removed the crank angle sensor.

fuel going in and out -YES
injectors-NO cause i havnt pulled the UIM off yet i was trying to troubleshoot everything else first. I do smell fuel occassionally coming out of exhaust. ( not flooded, i have deflooded it)
CAS- i never removed. now that i think of it i havnt tested to ensure its good. Ill try that as well

Use a test light with an LED, and check for injector pulse. The ECU applies +12v switched power to the injectors, and pulses ground through drivers. You'll need to hook the test light to 12v and probe the injector wires with the test light.

I had a no-start with my NA once that I almost couldn't figure out. Turned out that there was a large rubber hose going to the intake snorkel that was loose, allowing a significant amount of unmetered air to enter the engine. Check for leaks around the rubber TID (pretty prone to cracking).

One last thing. The emissions harness is 24 years old. It's been subjected to heat, cold, rain, grease, etc. for a long long time. My coolant sensor a few years back wouldn't read, even after replacing it. The connector wasn't broken on the outside, and was fully plugged in. The wires had come loose from the connector just enough that they wouldn't contact the prongs on the sensor. Since it had that little rubber thing on the back of it for Mazda's pathetic attempt at weather proofing ONE sensor connection, I couldn't tell it wasn't plugging in all the way.

Just food for thought :)

Make sure the coils have power on the B/Y wire w/key to on. If they don't then perhaps the ground from the Main Relay which attaches to the fender just below and to the side of the trailing coil is not grounding properly due to the new paint getting in the way and preventing the ground block from making proper contact w/the fender body.

If you are getting spark while cranking, your CAS should be working. If you have fuel, spark, and air, then it comes down to timing and the air/fuel ratio. If you didn't touch the CAS, then it comes down to the afr. It would have to be way off one way or the other to not even start. Most emissions removals get rid of things that add air during starting (AWS and BAC), so make sure your throttle plates are cracked and it is getting enough air. Or try starting fluid to get it running and troubleshoot from there.

did that this morning. even sanded down to the metal by the ground

Ill try starting fluid. gota get some from the store next time im there.

add to info: when removing the motor the wire on the o2 sensor got cut in half. will the o2 prevent it from starting? or just run like garbage?

It shouldn't prevent the car from starting.

If working properly then the Main Relay should click w/key to on and both the B/W wire and B/Y wire coming from the 4 wire plug of this relay should have battery voltage. The check connector w/the B/W wire located near the leading coil is a place to check for voltage w/key to on and this wire powers up the ECU.

it clicks and has power

ok so i decided to start over and go through the troubleshooting list in the FSM under the "wont start (cranks fine)" section. I am currently checking the coil w ignitor. When I check the (BY) wire to a good ground i get approx 11.9v. if i go from the (BY) wire to the (GY) wire on same plug i get approx 7.0v Should i make a ground from chasis to the (GY) wire to see if its not enough spark. I havnt rechecked the other coil yet. Should i reground it (assuming the (GY) wire is the ground. Thanks

cancel that. I relized the GY wire is the trigger not the ground.

The car only needs the leading coil to fire up the car. W/key to on the G/Y wire should have 5 volts then 0 volts in a repititious manner as the car is turned over "by hand," which can be done by rotating the alternator pulley.

ok so a few minutes ago i sprayed some starting fluid into the throttle body. It started for about 1 second then dies. it was rough but at least i know i do have spark. Does this give anymore clues on where to go. ive tried the deflooding procedures many times. so i dont think its that.

hey you checked your timing.. i know it doesnt start but i did a motor swap once and same thing it would run on starting fluid but that was it.... when i checked my timing i could not see the timing mark, turned out i had the CAS plugged in backwards causing the timing to be 180* out. so just check the timing to see if its close to TDC while cranking... and if it is plugged in backwards you still will have spark just at the wrong time so check this

i didnt mess with timing when i took the motor out. but i will check it just to be sure. im just wondering also if i didnt put something back on or something when i did rats nest removal. ill check timing though thanks

Can you keep it running for a little by spraying more fluid into the intake? If so, you are adding 'fuel' and are running lean without the fluid. Look for vacuum leaks.
Can you start it with the AFM unplugged and fuel check coupler jumpered?
How about with the TPS unplugged? Just trying to revert to as many 'default' settings as possible.

ya its not that you change the timing its that the CAS plug is part of the harness you would remove to pull the motor

ok went out and retimed it. it looked like it was good when i pulled out. just to doublecheck i did it correct. looking from front of car i lined up the notch to the right on the pulley to the needle on motor. pulled out CAS and aligned the dot with the notch on CAS housing. put back in and tightened up. correct?

still nothing. i may call autozone and see if they have a new set of plugs just in case all mine are fouled from flooding. weird thing is it wants to start with starting fluid but not on its own with just gas