So I took the car out today for its first trip since I bought it. When I bought it I replaced,plugs,wires,thermostat,belts,02 sensor,and the fuel filter. The car was running fine for about 30 minutes. I was cruising on the highway about 70 and the motor just died. It didnt stall or anything. It just turned off. After I got the car towed back home I checked for spark. I have spark. I checked to see if the fuel pump was working. I have fuel pressure. But the car doesnt even try to start at all. I'm new to rotaries what should be the next thing to check? I checked all the fuses and they all looked good. Thanks for any input.

 

Also when the car died the door ajar light came on. The light stays on with the key even though there isnt a door open.

 

check compression.

 

I will check the compression but that wouldn't make sense since the car was running fine up untill the point it died out of no where.

 

Year of the car please.

 

Year, what part of houston

 

Oh sorry. Its an 89 NA Vert. I stay over in Humble off 59/1960.
Before I bought the car the PO had replaced the ecu also.

 

So car turns over but does not start? Car has spark and fuel though. Correct?

 

Correct. But i'm not sure if the injectors are firing I only know that it has fuel pressure. I will be checking the injectors tomorrow also. Both coils were shooting off nice blue sparks.

 

Did spark plugs look flooded?

 

No they didnt but i'm going to pull them back out tomorrow and recheck them since I was cranking it over a lot. I did the deflood procedure by disconnecting the fuel pump just in case. Tried starting it again. Nothing happened still. It doesnt even try to start. I wouldn't think the motor would have been flooded anyway because I was driving it about 30 minutes before it died. The car wasn't having any issues accelerating or anything.

 

Turn key to on and the Main Relay clicks. When it clicks the Black/Yellow wire at the coils should have voltage and the Black/White wire at the green check connector located near the leading coil (has 3 wires) has voltage also. Appears that both of these will have voltage "but" if the ground to the Main Relay is iffy then it would cause these wires to cut out and the coils,injectors, ECU and so on lose power. If this occured the car would die but you now have voltage to the coils so "maybe" the Main Relay is working at times but not at other times so repeatedly turn the key to on and see if the relay clicks or not.

Another possibity is the wire going from the positive battery terminal to the "engine fuse box" may be a bit loose which would cut voltage to the Main Relay so double check this connection at the fuse box.

Car might be possibly flooded right now thus preventing the car from being started. If so go through the S5 deflooding procedure.

 

O.k I will check that out tomorrow as well. The weird thing is the door ajar light now stays on when the key is in the on position. Doesnt matter if the doors are shut. It just started doing that right after the car died.

 

With the key to on and engine off most of the idiot lights are supposed to come on. Also, when the alternator fails, all the lights are supposed to come on to warn of such an occurence. Make sure the plug/connection to the alternator is solid as well in addition to the connection from the alternator to the engine fuse box.

 

Exactly this as discribed happened to me a few years back with my 88 NA, driving 120 kph on the highway and the engine just quit. out of nowhere. towed it back home and after searching for 2 days it was a bad groundcable. It was a bad connection in a black cable coming from the fusebox under the hood.

Started right up after that and never had issues with it again.

 

O.k I have voltage at the wires you said to check. They all have 12+ volts. I rechecked the plugs they are all clean not flooded. I checked the voltage at the injectors. They were at 12+v. I checked the main ground. It has only 2ohms of resistance so thats good. I checked for a voltage drop. It seems fine as well. The main relay clicks. It still doesnt even try to start. I sprayed some carb cleaner in the intake just to see if it might start. Nothing happened. What else should I be checking?

 

Do you happen to have a gauge to measure the fuel pressure? If not, perhaps removing the rubber hose from the engine which constitutes the "return" line and place in a jug and jumper fuel check connector and turn key to on and see if the jug fills up with gas or not.

Also a one or two second shot of starter fluid into the air intake might tell you whether it's solely a fuel problem or not?

 

I just checked the return because I dont have a gauge at the moment. Fuel comes out just fine. I sprayed carb cleaner in the intake. Pretty much the same as starter fluid. The car still didnt even try to fire.

 

What else could keep the car from starting? I'm pretty sure the injectors are not firing because I just rechecked the plugs and ive been cranking on it for a while and its still not flooded. The plugs dont even smell like gas. Pretty clean too.




Edit: I just checked the compression. Its upper 90's on both rotors. So the compression is good.

 

Does the tach bounce when you try to start?

 

Yes the tach bounces while trying to start it. I checked for spark on the leading and trailing coils. I had spark at both.

What controls the injector pulse? I know the wiring of the injectors on both sides of the pins has 12+volts with the clip unconnected. Is it suppose to be like that?

 

i had something like that happen to me too. It was a neon though. I was driving down the highway and all of the sudden it said it was overheating so i pulled over and checked it and it was at a fine temp. then more and more random problems started happening eventually it wouldnt start at all. I eventually found a ground strap that had fallen off and once i got it put back on the car it ran fine like nothing had ever happened.

 

Yes, one wire is constant power and the other wire is battery voltage until the ECU fires the injectors and the voltage drops. You could check the primary injectors at the ECU to see if the ECU is firing the injectors or not from its side of things. Pin 3W (Light Green wire) is the front primary and pin 3Y (Light Green/Black) is the rear primary. You know it's supposed to read 12 volts w/key to on but engine off but you don't know if the ECU is sending the signal to the injectors to fire. So, you could take a LED light and place the negative LED light wire into the back of pin 3M and the other LED wire which is positive into a pin that has voltage w/key to start such as pin 1B (Black/White wire). When doing this the light should flash indicating the ECU is doing its part. Could be the injectors are just clogged or maybe the exhaust is clogged. All of these things are possibilities.

EDIT: And as two posters pointed out check the grounds.

 

Im going to disconnect the exhaust and see if it starts. I checked the main ground off the battery. It only had .2ohms of resistance. I also did a voltage drop. It only had a drop of .5v or less. So it should be good. I cleaned the ecu ground as well. It was good though. I will hook up an l.e.d to the injector wiring and see if its firing.


What other grounds should I be looking for?

 

Get yourself a cheap oil pressure gauge and 'T' it off the fuel line.
That's what I use.
Also, if you have a DVM w/ Duty Cycle function you can use to see if injectors are cycling when cranking over (Harbor Freight's top end excellent DVM has this function and can be had for ~$33 + tax w/20% discount coupon).

With the fuel line pressurized, disable the fuel pump an hit the key.
See if fuel pressure drops. Not dropping either clogged (unlikely) or injector not cycling during cranking phase.
At this point physically ground any of the injectors and see if pressure drops.
If pressure drops, try starting.
Starting might get you past 500RPM and place you outside the cranking phase (at least that's how it works on my '87 TII) and continue to idle.

I'm w/the other's that it's likelly not ECU related.

Also check your CAS at least per shop manual.