Hey everyone, I know everyone has seen the same old no start problem please check it out. So I bought and 88 RX7 roller and swapped all the guts from my old 86 over to it. This includes engine and harness's ECU everything the car was a roller. I have everything back together and have been trying to get car to fire up for the last couple months.
I have spark on all 4 plugs. I went threw the ECU harness and following the FSM guide for the Harness repaired and re grounded everything. Right now the car turns over I am getting fuel to the injectors. I checked the injectors on the Secondary rail and only have about 5v I know it should be 12v. I checked the primary injectors and have half the voltage to. I thought maybe it was a resistor pack issue to I disconnected it and checked the resistance across them and they were all the same. There is a strange humming/ vibration on the top of the upper intake I can't figure out whats causing it and only feel it with the key on. Also my dash Battery and Oil meters don't work/ come on when key is on. Also the shift up light is always on. The fuses under the hood all check good for continuity with voltmeter and I don't see any fuses blown on fuse box under dash.

 

What injectors are you using? Are they the correct impedance? ECU needs to see HIGH impedance injectors, so if you're running resistor packs, you should be using low impedance injectors. Whats the number on the side? should be like a 19550-XXXX.

Recheck the meter fuse. Thats what powers the gauges.

 

Number on the side of injector? There isn't one. They are stock brand new injectors.

 

 

Ok I looked at these stupid new injectors and they don’t have a number on the side. So I looked up the part number they are an MP-10820. Looked it up on line says they work for an 86/NA FC. I don’t see anything I dicating that particular number under the specifications of the part. I will test them later and see what the resistance come out as on the meter. Also I thought injectors supposedly to get 12v when key is on and all of them are only getting about 5v.

Also any thoughts on the vibrating noise coming from the throttle body when key is on? It’s very quiet and you can feel it when your touch the throttle body. I checked the BAC etc attached to it and nothing seems to be activating.

I do do have some things not plugged in under dash still. I have deleted some stuff over the years I will try to take some pics maybe I left something unplugged someone will notice. As for the shift up indicator being on constantly I have no clue. The clutch switch plunger works pretty good not sur inflation it’s plugged to the right harness though.

 

Ok measured injectors resistance on secondary rail and I am getting 2.3 ohms. Here are some pics of things under the dash that aren’t plugged in is there’s anything that should be hooked up that isn’t in these pics?



Not sure which plug the clutch switch plugs into here?

 

First off, get all of the loose connectors plugged in to eliminate those as variables. YOu can find wiring diagrams in the FSM at this site: Foxed.ca .

The injector plugs; i've found that sometimes the ground/trigger wire will read low voltage. Check the other wire and see if you're getting 12v. If that is indeed your injector power wire, check it again at the back of the ecu and see if you're getting the same reading.

As far as the vibrating, could it possibly be the fuel flowing throught the FPR? I honestly dont know. CAn you post a vid?

 

I will check voltage back at ECU again. As for checking voltage at injectors should I be checking from green power wire to the brown ground wires or to chassis ground. I also think I may have the TPS wire from ECU hooked up to wrong wire. There is a thick gray wire coming threw the fire wall it hooks up to that but I don’t think that’s right? In the forth pic you can see this gray wire next to that black clip. Vibration I found coming from BAC valve it only happens when key on and found it stopped when I unplugged the BAC. Most of the connectors in the pic have nothing near by to connect to? I will look at FSM again.

 

You need to check the B/Y wire going to the injectors for power. You can also check the check connector at the leading coil. Its on the same circuit.

 

Checked for voltage have it on the B/Y wire near leading coil. Also found TPS wire hooked up wrong fixed that. So now I am down to one wire not hooked up to computer and its a thick grey wire that runs threw the fire wall on passenger side. What does this go to? Still car turns over and over and not starting. I am wondering if this has anything to do with Inhibitor switch is this also know as Neutral Safety Switch? Thats on the Trans isn't it? Would that stop it from starting?

 

The only thick grey wire that comes to mind is the CAS wires, and it would certainly explain your car not starting. IIRC its 4 wires in one grey insulated jacket.

 

So I found out I stupidly switched the feed line and returns line around on fuel pump 🙄. Car starts now have new problem 🙄. At least I fixed bunch of stuff troubleshooting the issue I guess.

 

Now car starts right up but revs up to 4-5k but not a normal smooth rev up start like a rough missing type thing. Ideal comes down to 3k then drops down and car dies.
I found a couple vacuum leaks fixed those still same problem.

 

Sounds like you still have a vacuum leak. SMoke test or boost leak test would be the best way to find out, but if you can get the engine to idle, you can (CAREFULLY WITHOUT STARTING A FIRE) spray some carb cleaner around the intake manifolds. If you hear the idle change you have a vacuum leak. LIM gasket is a common place. If you have a large enough vacuum leak, the AFM door will stay completely shut, in which case no fuel will be delivered, after the open loop startup process.

 

Yeah, right now it’s still does that high rev then dies thing. It’s not smooth either kinda rough maybe a timing issue or TPS? I will check for further vac leaks. starts right up though. I don’t t ink it’s a bad seal I’ve felt with the hat before and had to rebuild engine.