Len-Len

iTrader: (9)

Hey everyone. I have a no start issue. A little history on the car:

Bought the car as a shell. It was missing many things including the drivetrain, front harness, engine harness, dash harness, and CPU. Bought and installed all missing items.

Just installed entire drivetrain. Rebuilt engine with non sequential twins conversion. This will be the first time the car has ever ran in my posession.

No solenoid rack installed.

Relocated coils to frame rail area.

Used Power FC serial number fd3s4.


When I first tried to start the car, the spark plugs were firing and the fuel pump was running, but there was no fuel getting into the combustion chamber. I checked and verified the fuel pump is operating at full capacity. Went to check to see if the injectors were firing, and then I found out both the injectors and the spark plugs are not firing.

So the car is now getting no spark or injector pulse. Still has fuel pressure up to the injectors.

I checked RPM through the PFC, It shows 200 rpm during cranking. The tach is NOT bouncing during cranking though, I don't know if I didn't plug something in when I installed the cluster, or if its the PFC just screwing up.

I went into sensor check. PIM, VTA, VTA2, WTRT, AIRT, and FUEL are darkened. They also read 4.99-4.98 volts and do not change at all during cranking or even when you unplug any of the said sensors.

I checked voltage at the boost sensor, tps, water temp sensor, and cas sensors, all have around 5 volts.

Now here's where I'm confused. I checked for ground at the connectors at all said sensors, each reading is at or way above 100 ohms. Some in kilo ohms. Is this normal or do I have a problem? Where do these sensors ground?



Long story short, I installed multiple wiring harnesses and a used PFC and don't know if I failed or if the PFC did. I also suck at reading wiring diagrams. Sorry for the long *** post, just wanted to be as descriptive as possible. Thanks in advance for the help.

Lenny.

Len-Len

iTrader: (9)

Ok I made a little progress. I began wiggling each wire at the ecu. When I did this, the Brown/Black wire broke off near the pin. I fixed that and now all the said sensors are functioning correctly.

The car still has no spark or injector pulse. The tach still does not bounce when cranking. What else can cause these problems? I have my crank angle sensors connected correctly (white plug nearest to crank) and the PFC reads 200 rpm while cranking. Suggestions?

danny hahn

Had a recent problem and did some checking on leading and trailing spark values mine were plus 7 and 1. the stock map at 200 rpms viewable on the commander is 8 and 0. so I think 7 and 1 were close enough. Does yours move off of the +25's when cranking?

With your latest fix are the 6 sensors still getting nearly 5 volt values and darkened?

ChromeThunder

iTrader: (2)

Len, I had a similar issue after my engine was rebuild. My car would not start either. I was not gettin spark or fuel at all.

Now, this is what happen to me... I found a broken wire on one of the Crank Angle Sensors. I fixed that and the car started fine. Then a bit later once warm the idle started to get really bumpy till the engine would just die. Then I was not able to start it back until it was cooled down. I changed one of the sensors with a new one and the issue went away.

After doing A LOT of research I learned (Anyone pls correct me if I am wrong) that the ECU will not put out any fuel or spank until it sees one full rev on the engine which is piched up by the CAS. Thats why my engine would not start. Look up some of my old threads if you would like to read up on what I had issues with. I appologize for not posting a link to it but I just figured I could drop in a few lines to help you since I am in the middle of something right now. Please let me know if there is anything else or questions you may have.

Good Luck

ChromeThunder

iTrader: (2)

Len,

I had a similar issue after my engine was rebuild. My car wouldn't start either. I was not getting spark or fuel at all.

This is what happen to me...
I found a broken wire on one of the Crank Angle Sensors (CAS). I repaired the wire and I was able to start the car. A little after that another issue emerged. Once the car was warm the idle would start to get really bumpy until the engine would just die. Then I was not able to start it back up until it was cooled down. I changed one of the sensors with a used one and the issue went away. I took Ohm readings on the sensors and according to the serv manual they were within limits. Then once the CAS got warm with the engine running the ECU will pick up a resistance reading outside the allowed range. Temperature affects resistance therefore the numbers were out of limits.

After doing A LOT of research I learned (Anyone please chime in if I am wrong) that the ECU will not put out any fuel or spark until it sees one full rev on the engine while cranking. The signal is picked up by the CAS. Thats why my engine would not start. Look up some of my old threads if you would like to read up on what I had issues with. Please, read on the second page. Here is the link.

https://www.rx7club.com/south-rx-7-f...-883721/page2/

Please let me know if there is anything else, Good Luck.

ChromeThunder

iTrader: (2)

Sorry for the double post but I added the link to my old thread

Len-Len

iTrader: (9)

Danny hahn and ChromeThunder, thanks for the advice! I haven't had time to look at it today but I will tomorrow night and let you know. I am really aiming towards the CAS, as the tach doesn't bounce when cranking. Its kinda weird how the PFC is reading RPM. Maybe only one of them isn't working and causing that?

Danny hahn, when I fixed that wire, all the sensors were no longer darkened and are now reading voltage correctly.

Dvst8

iTrader: (6)

When you say the white crank angle sensor is on the crank side you mean its hooked on the left(passenger) side right? I had the a similar issue where I hooked up the cas sensor on the wrong side and couldn't get the engine to crank over. Switched the wires and started like a champ.

If your not getting spark, I'll check your coils or could even simply be a fuse.

Len-Len

iTrader: (9)

Everyone, thank you for the input! I finally got it started.

There was 3 problems causing the crank no start, all of which were my fault for not seeing earlier

The thread holes where the igniter mounts were rusted badly. I ran a tap through the holes and my spark came back like magic.

2 of the fuel hoses on the firewall that connect to the engine were reversed. The fuel hoses and lines at the engine have a colored dot on them. I just matched the colored dots on the hoses to the lines and assumed they were correct. Found out the fuel feed and return hoses were reversed.

1 instrument cluster connector had corrosion on the pins. Cleaned up the pins and the tach started working again.

So there you have it. I hope no one makes my silly mistakes. Thanks again fellas!