87 No Start

[ITS57]

I'm building an 87 ITS RX-7. I disassembled the entire car to paint,remove all rust proffing and sound deading tar mats, stole roll cage ideas from speedsport reassembled and of course it will not start unless I squirt fuel in the intake and fires right off for about 10 seconds. I have gone through the steps in the FSM and all ohms are correct all continuity is correct,fuel pressure etc. I made a test light for the ecm codes, it goes through the test cycle and shows no codes, if I pull any sensor wire off it sets that code so I'm fairly sure there are no sensor issues. The only thing I've found that is not right is I have no voltage to the injectors. Is there anything I might have missed before I try to get the nearest dealer to test the ecm? This was a perfectly good running street car untill I got ahold of it. Any help would be greatly appreciated. Thank You

[JeffYoung]

I think you answered your question -- no voltage to the injectors.

[ITS57]

Thanks, guess I'll be going to the dealer.

[jrx13]

I wouldn't bring it to the dealer. The mechanics that are there probably weren't working there when the car was new.

Since you have fuel pressure it shouldn't be a fuel pump or relay problem. Next step is to see if the injectors are firing. Do not check the secondary injectors while cranking. I am pretty sure they don't fire for cranking. You'll have to check at the primary injectors.

You didn't happen to remove the fuel injector resistor pack located near the right front strut tower did you?


-Jack

[seckerich]

If you have a spare crank angle sensor plug it in with the key on and spin it with your hand. You should hear the injectors clicking. 86-88 has a ballast resistor located under the AFM that reduces voltage to the early injectors. Did you plug this back in? It is a silver box looking thing with a 6 pin plug I believe. The ECU closes the circuit to ground to fire.

[ITS57]

I have the ballast reister plugged in and it test 6.5 ohms so it should be good. In trying to test every thing I pulled the intake off and the primary injectors out,plugged all the sensors in, wired the injectors to the fuel rail so they would not blow off and cranked the engine. No clicking, no fuel spray. Thats when I checked for 12 volts at the injector and and found no voltage. I guess I'm asking is there something I missed for the ecm not to be sending voltage to the injectors. You know how the ecm gets blamed for all the problems and its usally something else not the ecm. If it is the ecm, does anyone know a good shop I could send it to to check it. Thank you all for your help.

[seckerich]

You missed the point. The ECU does not send voltage to the injectors, they have power all the time. The ECU closes the ground side to fire them. See if you have voltage at the resistor. Big black/with yellow stripe is power feed from the main power relay. Start from there and see where you loose power.

[ITS57]

OOOOHHHH......Thats very different than what my pee brain was thinking. I knew I was missing something! Thank You! Thank You! Thank You!

[rx7chris]

There's also a relay under the dash that if not plugged in or bad will cause the car to not start either. Used to have to pull it to get my street car started then plug it in once it turned over. There's also another relay under the hood that will do the same thing.

[ITS5GB]

So Shant, something you want to tell us?:cool:

[ITS57]

I found corrosion on the AFM sanded the terminals,check for 12 volts at the reisistor ok, now I have voltage at the injectors. Still no start. Hooked up a spare crank angle sensor and spun it with the key on and no clicking from the injectors. I can hear clicking coming from the trailing coil pack area. Thanks, Ron

[NCRX7RACER]

Are all of your grounds hooked up? Rear of engine to firewall? Under the emission / vacuum lines beside the oil filler tube?

[ITS57]

I do not have a Ground wire in that area. I have a multiable ground from the wire harness to the intake support. Thanks Ron

[NCRX7RACER]

Did you unhook your fuel lines where they enter the metal lines on top of the block? (from the firewall to the block) Check to see if they got reversed. I know you think the problem is electrical, but it is worth checking this too.

[ITS57]

Yes I Checked that,and the line from the fuel filter goes to the primary injectors. This engine hasn't been started in about 7 years I've done the 2 stroke oil in the rotors. I've read that pulling to start is a option also. Thanks for your help. Ron

[Eagle7]

...it will not start unless I squirt fuel in the intake and fires right off for about 10 seconds.
... This was a perfectly good running street car untill I got ahold of it.

This engine hasn't been started in about 7 years I've done the 2 stroke oil in the rotors. I've read that pulling to start is a option also.

Is this the same car? If it runs fine when you squirt fuel in the intake, pulling it isn't likely to help. You need to find out why you're not getting fuel.

Do you have 12V on one pin of an injector plug? You should be able to reach a secondary plug without disassembling much. If no 12V, that's your problem. If 12V, then it may be an ECU or sensor issue.

Does the fuel pump run if you push the flapper on the AFM open? If not that's your problem. You should be able to force the fuel pump to run by jumpering a two conductor plug near the passenger fenderwell.

[seckerich]

Keep it simple. You already know you have ignition. Fuel pressure is good so find out why your injectors are not firing.

1. Injectors that sit for a long period will stick shut. Pull out the primary injectors and put 12 volt to them. Polarity does not matter, it is just a coil. Can you blow through it with power applied? Shoot carb cleaner through it.

2. Do you now have voltage to the injectors at the plug? Do not expect a full 12 volt. Hook an ohm meter to the other wire and see if it cycles to ground when you spin the CAS. This will tell you if the computer is doing its job. Now you can be certain where the problem is. Common power wire in injector plug is black/yellow stripe, and signal wires (ground switching) are light green with stripes in the color for that location. You are getting close, don't give up.:026:

[ITS57]

Yes it's the same car. Steve and Marty you both have givin me lots of great info!!! I will be working on the car tonight using all your great suggestions! I'm not going to let this thing whip me! Thanks, Ron

[Eagle7]

2. Do you now have voltage to the injectors at the plug? Do not expect a full 12 volt. Hook an ohm meter to the other wire and see if it cycles to ground when you spin the CAS. This will tell you if the computer is doing its job. Now you can be certain where the problem is. Common power wire in injector plug is black/yellow stripe, and signal wires (ground switching) are light green with stripes in the color for that location.

Clarification - this ohmeter test needs to be one of the primary injector plugs. The secondaries aren't used until after 3800 RPM.

[NCRX7RACER]

"car sitting 7 years". How rusty is the inside of the gas tank? Are the fuel lines clear of gunk? Seven year old fuel can turn to glue and plug the lines from the tank on through the system. You may get fuel pressure but if you get it running you may lack enough flow under a load.