frigging frustrating
 

Short story:

85 SE, replaced running four port with original,(off another running/wrecked car), six ports. Turned key, car floods, went through FAQs, archive tried it all . Cursed a few times. Car does not floods as bad, but it does flood some.
Tested everything, injectors, pump, ignition & wires, changed plugs, change computer, changed injectors, changed fuel pump, put gas, in tank, cursed some more. I have good ground, fully charged battery, good wires, good coils, good rotor and cap.
Twice I've gotten in the car after sitting overnight and started it for a second. After that initial puff, nothing. Yesterday, I pulled the car around the neighborghood and still would not start. Went through everything on the service manual and still can not figure out what is going on. I usually do not ask for help since most of the time I can figure things out withi in a couple of days. I've being working on this thing for about a week and Im about to set it on fire.
Can some one help me out. I am sure that I am overlooking something small.
:bowdown:

Check and see if the fuel pump comes on with the key in the on position before you start to crank.
Forgot to add. Did you do a compression test? Also did you verify you have spark out of leading and trailing sides?

Also need to know how old is dist rotor?

compression and apark
 

I did not mentionet it since it is some of the stuff cover on the FAQs and archive. BUt yes I did check and the pump does not come with the ignition on. Compression is at 140 front and rear on the trailing and somewhere around 120 on the leading plugs.

Did you verify spark out of both leading and trailing sides. And also need to know when rotor was last replaced?

spark & rotor
 

I got spark on all four wires of the distributor. I got spark on both coils. I have replace the distributor with the distributor that was running just last week. The rotor is fairly new. In other words it is in excellent condition.

If you have a spare rotor try it. Just amuse me here, i will let you know why later. Also is the Coolant temp sensor plugged in and is it off the se motor or the other one? Also check the condition of the flap door on the AFM to make sure it is not bent.

Thermo sensor
 

The original thermo sensor broke off. I have another plug to thw wire that came off a second gen. I have a brand new rotor that I am saving for a rebuild. Does the thermo sensor makes that much of a difference?

not to hijack this but i don't remember if it was you rx7doctor or maybe gsl-se addict that posted a set of steps which involved every electronic component down the line to fire the sparkplug. i knew i should have saved that.

oh yes the thermo sensor tells the ecu when to run rich or lean depending on the current water temps.

When you say that the original sensor broke off. Are you stating that the connector that attaches to the sensor broke off?

And as Gavin has stated, yes it does make a big difference. The coolant temp sensor usuall y when it goes bad has high resistance which tells the computer to richen up. If the connection is bad to the sensor and there is no signal to the ECU the motor will not start.

Try that new rotor also. Also like i said look at the flap door on the AFM. Is the AFM the same one that you were using before? Did the engine backfire at anytime during your initial steps to start?

Gavin, i dont remember if i posted about that or not. It might have been gslseaddict.
Also check all of your fusible links that are associated with the injection system.

Thermo sensor
 

That makes sense; But it should;nt keep it from starting. The small amout of fuel that is setting on the plugs is not that bad to keep it from starting. I am leaning more towards a lack of spark thatn too much fuel, but the fact that the sparke is present throws me off...

Also are you sure the timing is correct. It is possible that the pulley on the eccentric shaft was put on wrong once and when you dropped in the other dist it is now way off.

well that sounds like a timing issue to me then, here's a couple good links to set it if you like. https://www.rx7club.com/1st-generation-specific-1979-1985-18/help-may-really-long-368922/
http://members.optusnet.com.au/~onec...-%20part%20one
https://www.rx7club.com/1st-gen-archive-71/ignition-main-pully-timing-525909/

timing, minor common sense stuff
 

First thank you guys for working with me on this. I do belive more than one person brainstorming comes to a quicker and reasonable solution. I have set and reset the timing. The motor in the car came out a running car so none of the pulleys were off the motor. The distributor was change and place in the proper manner, (alignment). I am really leaning towards the thermo sensor, provably creating the frustration.
There are not many rotor heads in the area so the availlability of parts is minimal. Will make some calls tonight and try to get a sensor from someone. What else I need to do other than replacing the rotor?

Iirc, none of the thermo sensors, coolant or intake air would cause a no start, as the ecu will default to one limit or the other of the sensor, if no reading is present.

Wet plugs are a clue, take them out and clean them. At this point, you may need to de-flood.

trochoid, sorry i am going to have to correct you. Your theory on the Ecu would be correct if we were dealing with todays Obd2 or 1 systems.
A bad coolant temp sensor 99% of the time will cause the ECU to dump fuel. A lack of signal from the CTS or being disconnected will not let the car start. This is a FACT.

Thermo Sensor
 

The Service manual does call for the thermo sensor to be a checked item on the no start troubleshoot. I had suspected it, but did not thought it would be a problem.