kutukutu1

iTrader: (5)

hey guys, i have read many threads and done everything when there is no spark , cleaned the grounds, checked the g/y with voltmeter and b/w as well and they both provide electricity, now when the electricity goes into the coils, its not coming out of the coil b/c when i do the screwdriver test with the spark wires, no spark. i have not checked the crank angle sensor, the tps is fine. i crank and the tack does not move, i have checked all the fuses in and out of the car and i have also made the led code reader and no codes are being sent. help i dont know what else to do. sorry , its an 88 vert n/a,

p.s it turned on before and it did this once in a while, moved a couple of cables and it worked again, until the next time it did it, now it did it, but no matter what i do, nothing.

satch

iTrader: (1)

1. When you test for spark are you grounding the plug wire or not. I know you are using a screwdriver but is the screwdriver being grounded?

2. Go ahead and check the CAS as it is a simple check.

3. "What cables" did you move in the past that provided you with a quick fix leading to spark being created?

4. Have you checked the coil ohms and compared them to spec?

5. Are you certain the engine/ECU grounds are up to par.

6. Have you tried disconnecting the plug to the AFM and tried to crank the engine and check for the evidence of spark?

RX200013B

also check the main relay

Len-Len

iTrader: (9)

This happened to me once and it ended up being a shitty connection right where the wires meet the CAS. So I'd check the CAS.

kutukutu1

iTrader: (5)

thnaks guys ill do that in the morning, main relay is the one under the dash right?

the easy fix was with the connector in the trailing, the one that has 4, i would disconnected it and when i connected it back i would hear kinda like a click and it would crank right up, this time though i had to do it a couple of times before it clicked but it still did not crank.

how do you check the CAS?

yeah the screwdriver test was done right

how do you check the coils ohms and were is it in spec?

were is the ecu ground? i dont think i have cleaned that one

i dont understand what you mean with unplugging the afm and checking for spark? why disconnect it?

thanks to all for replys

fc3s91

iTrader: (23)

Have checked the egi fuse?
Before you start testing, get an fsm. Then check back here.
Thanks Robert
http://foxed.ca/foxed/index.php?page=rx7manual

kutukutu1

iTrader: (5)

i already downloaded the fsm, now i havent checked the egi fuse will do as well.

satch

iTrader: (1)

Your engine not cranking can be a completely different issue then not providing spark as it would be hard to create spark if the engine doesn't crank over. You say the coils are getting voltage but you don't have spark coming out of them is this true? The coils get voltage from the Black/Yellow wires attached to the coils. Are you certain you have voltage on this wire w/key to on? If you don't then the EGI INJ fuse is bad as previously mentioned or the Main relay is not operating properly which can be due to a variety of causes or the Engine fuse is no good or you have a bad connection at the coil (trailing) as you have outlined.

wmele25

iTrader: (3)

i would check the main relay again. when i bought my car it wasnt running because it didnt have spark. i did everything it sounds like you are doing and after three days of angry trouble shooting i replaced all the electrical system from one of my other cars. it turned out it was the main relay. even though i tested voltage in and out of the main relay the relay was bad. i cracked it open to see what the deal was and i found a relay coated in deep rust so voltage was getting through the relay but at really high resistance. to high to get enough voltage to the computer and coils. just a thought.

kutukutu1

iTrader: (5)

the car was cranking, yesterday i went to try again and it dosent crank now, when i go to on everything turns on normal, but when i turn the key to cranck everything just falls on its face. i have checked for voltage going into both coils and it is. ill check over the engine fuse again, the fuse is not blown but it could be bad, ill change it. ill test the main relay. thanks guys ill keep you updated

satch

iTrader: (1)

So you're saying that the starter is not turning over? If that's the case then there is obviously a problem with something within the starting circuit. The starting circuit begins with the ignition switch and ends at the starter. If the starter is not turning over then the engine won't crank but these are issues that are not related to the coils sparking and so on. Thus if the engine cranks but doesn't have spark that is one thing, but if the engine doesn't crank then it's not possible for spark to be present.

If the coils have voltage on the B/Y wire w/key to on then the Engine fuse, interior fuse box, is okay.

If the car does not crank then find the blue plug located by the main relay and test for voltage w/key to start on the Black/Green wire. Remember, if your car requires the clutch to be depressed to start the car then the clutch needs to be depressed in addition to the key being turned to start to check for voltage on the B/G wire. If your car does not need the clutch to be depressed for starting purposes then all that is necessary to check the B/G wire would be w/key to start.

kutukutu1

iTrader: (5)

i found that my starter decided to crap out so i am getting that fixed. until i fix it i can do anything else. the cas is good, the main relay is good, egi fuses are good.

i havent checked the cpu ground, will do tomorrow

were is the engine ground? i cant seem to find it in the fsm.

thanks for all the help

satch

iTrader: (1)

Engine ground: http://www.aaroncake.net/rx-7/grounding.htm

CPU no!!!!!!! ECU=YES!!!!!!!!!!!!!!!!

Checking the CAS. Was this done at the CAS itself or at the ECU? If at the CAS that doesn't verify that the wiring to the ECU is decent enough to do the job.

How did you check the Main relay?

kutukutu1

iTrader: (5)

i did check the cas at the cas itself not in the ecu

the main relay i opened it and connected it and i could see the relay working

kutukutu1

iTrader: (5)

k guys, update, i checked the ecu and checked all the connections for the cas,both coils and all the grounds and everything is fine and i double checked the main relay through the ecu and its perfect. i havent tried to start it since my starter crapped out, but ill keep you guys updated.

one thing i did notice was that the spark wire had a resistance of 10k ohms

satch

iTrader: (1)

"one thing i did notice was that the spark wire had a resistance of 10k ohms "

Specifically, which spark wire are you talking about?

kutukutu1

iTrader: (5)

the trailing coil, the wire thats closest to the firewall was the only one i tested.

satch

iTrader: (1)

I guess you're talking about a spark plug wire.

kutukutu1

iTrader: (5)

yea thats it

kutukutu1

iTrader: (5)

k guys update, i got a new starter, it cranks hard, but still no spark. everythign i ve done

Checked for voltage at the B/y wires good
cleaned all the grounds, ecu, coil, all of them good
checked the CAS, Grounds, and coils through the ecu and everythig is to spec
checked all the inside fuses and egi fuses
main relay i double checked that it was working by the ecu and by opening it and putting direct power and seeing both relays click
the battery has full charge
did the afm test to see if there was a short, but even with it disconneted still no spark(checked by pulling the spark plug)

any new input guys, i need help

satch

iTrader: (1)

I can't remember if you checked the Green/Yellow wire at the leading coil. How about disconnecting the 4 wire plug to the trailing coil and focusing on the leading coil. When you check for spark it's best to rule out as many things as possible by removing a plug from the leading coil and placing the spark plug wire as close to the bore as possible while at the same time leaving a small space between the two and then check for spark. This should require two people to do (starter and an observer).

You should also begin to check the wires that lead from the CAS to the ECU as well as the G/Y wire that travels from the leading coil to the ECU. The CAS has 4 wires going to the ECU. With the plug removed from the CAS and the largest plug disconnected from the ECU. Pin 1N is Green, pin 1P is Blue, pin 1Q is White and pin 1T is Red. Do a continuity/ohm test on these wires and afterwards reconnect both plugs and w/key to on check the voltage at these 4 wires at the ECU and all should read less than 1 volt and most likely closer to 0 volts. With the leading coil plug removed and the same plug(largest plug) removed from the ECU do a continuity/ohm test on the G/Y wire which would be pin 1V.

And while your at the ECU get a voltage reading on pin 2A w/key to on and see if it is 4.5 to 5.5 volts. Pin 2C= 0 volts, pin 2E= 4 volts, pin 2R= 0 volts, pin 3A= 0 volts, pin 3G= 0 volts. All these again are checked w/key to on.

kutukutu1

iTrader: (5)

I have already checked at the ecu the cas in all plugs both coils in all plugs all grounds main relay as well. What your telling me I did it I am out of ideas

Rx-7Doctor

iTrader: (13)

I had gone though all of this once on a 88. After performing all of the tests I had a spare ECU, installed it and the car ran. You can usually get one cheap from a member here. No promises that it will solve your situation as I am not the one working on the car. :-)

kutukutu1

iTrader: (5)

Thank you I appreciate the help. Do you know of anyway to check the ecu? I have already spent slot of money in the car the last thing I wanna do is spend more

Rx-7Doctor

iTrader: (13)

Unlike the earlier 1st gen SE model they do not show a "Manual" way of testing at the ECU.

However it should be the same. Only difference here is you cannot start the engine and bring it up to operating temperature to verify all of the correct inputs. In this case however it may be enough just to check the proper grounds and inputs by back probing the wires at the ECU and comparing results as listed in the link I have provided. Remember the values listed in the FSM are for a Engine that is at operating temperatures and the values you get may differ. I cannot guarantee that the procedure that I have recommended is accurate or not. However the only choices you have is to try it or just find a known good ECU and install it.

The only difference I can see between doing the test manually and using the factory Diagnosis checker is that the factory one allows you to test whatever pin by turn the **** to that particular one and then showing you the reading for that circuit.

http://foxed.ca/rx7manual/manuals/19...SYSTEMS_NA.pdf

I know that the Vert ECU is going to be a little harder to find that your standard model one. Yours is a N338.