AEM Series 2 problems (cranks, no start)

[dsamani]

To start, I have an S14 with a KA24DE.

Hey, I have been trying to get my car to start but all it does is crank. I have an AEM Series 2 30-6610 and I added in wiring for Pin 46 (Wideband) and Pin 66 (MAP sensor) as per the documentation. When I read the wire directly from the MAF I get 1.6V, however AEMTuner is saying that the MAP voltage is 5.1V. I have power for the MAP sensor tapped off of the TPS, which uses a 5V source. I saw in the docs that I can pull power from the ECU, however I already had it set up this way and I would only need to run one wire.

My wideband also reads an AFR of 10.1 at all times, as if it's ignoring the signal from my AEM Wideband.

Also, my engine load changes with throttle, as per the docs this indicates a problem with my MAP wiring but I can't figure it out.

I verified mechanical cam timing before putting the valve cover on, and I have timed the distributor (remove cyl 1 plug, put cyl 1 in TDC, put distributor back in with dot and groove lined up).

I have verified I have spark by removing the cyl 1 spark plug, touching it to a ground with the plug wire on it, and attempting to start the car.

Help!

[dsamani]

Update

Been diagnosing all day. I jumped the starter signal wire to positive so I could crank engine on my own and verified that the injectors are not firing. I have +12V at each injector, so this indicates that I'm not getting a ground signal from the ECU.

I also get nothing when I use a stock ECU, so this must mean I have a ground issue somewhere on the ECU harness.

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[dsamani]

Update

Still no start. I get start sync when I crank according to AEMTuner, so my CAS is working. I also checked continuity between the injector plug and the ECU plug, that's good. Hooked up a noid light to the injector plug, still nothing. I'm not sure where else to look at this point.

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[nismo racer]

i had a similar issue, go see if the injectors are turned on. i forget where exactly where it is but i had to turn them to on. idk why but thats what i did.

[dsamani]

Originally Posted by nismo racer

i had a similar issue, go see if the injectors are turned on. i forget where exactly where it is but i had to turn them to on. idk why but thats what i did.

They are on. In AEMTuner I can see it signaling the injectors. I also put the stock ECU in and they still don't fire.

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[nismo racer]

welp thats all i can think of... check fuses?

[Yellow4g63]

Originally Posted by dsamani

To start, I have an S14 with a KA24DE.

Hey, I have been trying to get my car to start but all it does is crank. I have an AEM Series 2 30-6610 and I added in wiring for Pin 46 (Wideband) and Pin 66 (MAP sensor) as per the documentation. When I read the wire directly from the MAF I get 1.6V, however AEMTuner is saying that the MAP voltage is 5.1V. I have power for the MAP sensor tapped off of the TPS, which uses a 5V source. I saw in the docs that I can pull power from the ECU, however I already had it set up this way and I would only need to run one wire.

My wideband also reads an AFR of 10.1 at all times, as if it's ignoring the signal from my AEM Wideband.

Also, my engine load changes with throttle, as per the docs this indicates a problem with my MAP wiring but I can't figure it out.

I verified mechanical cam timing before putting the valve cover on, and I have timed the distributor (remove cyl 1 plug, put cyl 1 in TDC, put distributor back in with dot and groove lined up).

I have verified I have spark by removing the cyl 1 spark plug, touching it to a ground with the plug wire on it, and attempting to start the car.

Help!

IS this your 1st start up with the ems? is stat sync on when cranking or is it off?

[dsamani]

Originally Posted by nismo racer

welp thats all i can think of... check fuses?

Can't imagine which fuse I would need to check for injectors though

Originally Posted by Yellow4g63

IS this your 1st start up with the ems? is stat sync on when cranking or is it off?

Yes, first attempt to start. I do get stat sync when cranking.

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[tayloray]

I had the same problem on my S14 with an SR and a series 1 AEM. I spent countless hours trying to figure it out.

Checked everything to no avail. I had swapped the interior dash harness when I did the swap.

After Awhile I swapped my old dash harness back in, and that was it. So essentially it was something to do with that white plug that goes to the interior harness.

[dsamani]

Originally Posted by tayloray

I had the same problem on my S14 with an SR and a series 1 AEM. I spent countless hours trying to figure it out.

Checked everything to no avail. I had swapped the interior dash harness when I did the swap.

After Awhile I swapped my old dash harness back in, and that was it. So essentially it was something to do with that white plug that goes to the interior harness.

This could be it, as the previous owner swapped the dash. There may be a loose interior ground. The one near the ECU in the passenger footwell is tight.

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[tayloray]

Originally Posted by dsamani

This could be it, as the previous owner swapped the dash. There may be a loose interior ground. The one near the ECU in the passenger footwell is tight.

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I would go through that harness. That's what mine was. Same situation. No stat sync. Power in injectors and coil pacs and cas, no ground.

[dsamani]

Originally Posted by tayloray

I would go through that harness. That's what mine was. Same situation. No stat sync. Power in injectors and coil pacs and cas, no ground.

I actually am getting Stat Sync though, but ill go over the harness.

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[tayloray]

Originally Posted by dsamani

I actually am getting Stat Sync though, but ill go over the harness.

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I may have gotten that as well. (after some time of troubleshooting) Hard to remember as it was about 3 years ago.

[ka-titties]

Check all the ground locations in the FSM. There's a page where it tells you where all the grounds are.

[dsamani]

Originally Posted by ka-titties

Check all the ground locations in the FSM. There's a page where it tells you where all the grounds are.

Thanks, ill check it out!

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[dsamani]

I checked the grounds, they are all attached to the chassis and have good continuity.

I also found the sub harness for the crank position sensor and hooked it up, still no injection.

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[dsamani]

Update

Noticed that two white plugs near the drivers side fender inside the car were unplugged. Plugged them in, gonna see if that helps.

Edit, battery is dead. Got it charging.

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[dsamani]

Update.

Still no fuel. I unplugged the connector and tested the voltage, I get +12V.

However, get this, when the car is cranking the voltage at the injector drops to like 6-8V. Not sure if that means anything, but it may not be enough voltage to open the injector.

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[dsamani]

Update.

This morning I now have a fully charged battery. I checked the voltage drop on the injector under cranking and it's now only 9.5-10V, which shouldn't be a problem.

Clearly something must be disconnected, but I can't find out what.

Also found out from previous owner that an SAFC had been installed. Some wires in the harness have had their insulation split, and when the SAFC was removed the splits were covered with electrical tape. The only wire that was actually cut was the MAF, which shouldn't matter as I'm on a MAP sensor now.

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[chriskilla2]

Do you have your iat setup? Didn't read anything about you doing thar

[dsamani]

Originally Posted by chriskilla2

Do you have your iat setup? Didn't read anything about you doing thar

IAT is hooked up to the stock wiring with a GM sensor, and I don't believe this would cause a no start issue.

AEM is also reporting a valid signal from the sensor.

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[dsamani]

Update:

Removed distributor and spun the gear. Good news, everyone! I hear the injectors firing just as I did when I had removed it previously. Still have no idea why its not starting up.

Put distributor back in, attempted to crank (after a brief flood clear, just in case) and just ended up with nothing. I heard the puffs coming from the exhaust as it tried to spark whatever fuel was dropped into the manifold, but after a few cranks that went away.

This tells me that it WANTS to start, but for whatever reason the injectors aren't opening under cranking!

What the fuuuuuuuuuuuuuck... I've stumped every person that I've asked about my car. Just nothing.

[nismo racer]

I'm stumped too. It's hard to diagnose a car via the interwebs... My way of diag would be check fuses, grounds, and check signal to the injectors. Obviously you figured out the injectors are firing but not when you crank it on. Now see what the ignition has to do with the injectors. Maybe a common wife? I'm a little fuzzy with kade wiring since I haven't messed with mine in some time.

There has to be a common thing between the two.

Use a test light to check fuses.

[dsamani]

I should note that I have Fuel Injector Clinic top feed injectors, which use a Bosch core.

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[Yellow4g63]

Have you tried playing with the injector voltage table? if your cranking and only showing 10v to 9v u might need to adjust it so it will fire up. Have you made a thread on the AEM forums yet?

[dsamani]

Update

I tried fucking with the car under the assumption that I was wrong and the injectors are firing.

A friend of mine suggested that I should try a completely stock tune with just the battery offsets changed and try that out. I did and I got a cough, then a huge BANG!

SO THE INJECTORS ARE WORKING!

This means that:

My tune was not injecting enough fuel.
Something is very off-time.
Or both.

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[dsamani]

Update

Verified that cam position and cam timing is correct. Still no dice.

Right now I think the issue might be with my tune.

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[Yellow4g63]

Did you use the drop down menu for the injector battery offset? You might want to check your A/F ratio while it's cranking and play with the start up enrichment tables.

[dsamani]

Originally Posted by Yellow4g63

Did you use the drop down menu for the injector battery offset? You might want to check your A/F ratio while it's cranking and play with the start up enrichment tables.

Yup

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[tayloray]

I can send you one of my old tunes that i know worked.

Edit, keep forgetting this is on a KA.

Be sure to verify on the AEM what sensors you're using.