Fuel pump does'nt stay primed
 

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how is your fuel pump wired to the MS?

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You mean directly to the fuel pump relay :)

does it run if you jump f/p and gnd in the diagnostics box?

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should be 35psi at idle and around 45-50psi at atmospheric

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The normal behavior of the MegaSquirt is to prime the fuel system for 2 seconds after key on, then shut off the fuel pump unless there is a valid incoming RPM signal.

Yeah, this sounds like a trigger problem to me. The MS may simply not be reading the crank / cam sensors. When you made the swap, did you transfer the CAS from the old engine to the new one, or have you re-wired for the '02 engine's discrete crank and cam sensors?

Why don't I see RPM in that log? I don't mean that it's zero, I mean the column for it is missing.



Also, ignore the fuel pressure indication in MS. Unless you have actually installed a fuel pressure sensor and connected it to the MS, this reading is completely bogus.

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Well, on the plus side, it's probably a simple fix then. Most likely a CAS-related wire got cut / broken / squished / not plugged in during the swap.


During cranking, you should read somewhere in the vicinity of 200-300 RPM on the MS, assuming a healthy battery and starter. Until you achieve that, nothing is going to work.

Tip: while you're troubleshooting, remove the spark plugs and disconnect the primary (low-voltage) side of the ignition coils. This will greatly decrease the load on the battery and starter. Also, disconnect the electrical plug for the fuel injectors, so that you're not constantly spraying fuel into the chambers. (The injectors fire once every time you turn on the ECU, regardless of whether the rest of the system is working or not.)

Your dashboard tach may not be working either, but don't worry about that for now. It's the tach in TunerStudio / MegaTune that you need to worry about.

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Assuming you have continuity all the way across the white wire (from CAS to ECU) and it is not shorted to ground, the CAS is likely at fault.

To rule out an ECU or wiring fault, disconnect the CAS and measure between the white wire and ground at the harness connector where the CAS would normally plug in. You should see +5 here with the key on. If not, it's an ECU or wiring problem. If you do see +5 here with the CAS disconnected, but it goes down to 0v constantly with the CAS connected, it's a bad CAS.



The MS1 CPU does not support the NB-style crank or cam pattern. You must use an NA CAS (or a fixed-pitch crankwheel such as a 36-1) with the MS1 CPU.

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Good luck with that. So far as I'm aware, the artwork has never been released.

OTOH, this is only a 4 layer board, and I'm 99% certain that the inner layers are nothing but power and ground planes, so it should be easy to trace visually.

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?

You're certain it's not just a via from top to bottom?

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If you have a stable and believable RPM signal while cranking on the starter, then you don't have the CAS wires reversed. If they're flipped, the unit won't sync properly.

You said you did a 1.8 swap, right? Be aware that the ignition coils on the 1.8 engines are backwards as compared to the 1.6 engines. As viewed from the front, the right-side coil on a 1.6 engine connects to plugs 1 and 4, and the coil on the left connects to 2 & 3. With the 1.8 coils, the right side is 2 and 3 and the left side is 1 and 4.

So you may simply have the plug wires reversed. Happens to all of us. Try flipping 'em around.

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No! Absolutely not. You must use one or the other of:

1.8-style coils, wired directly to the Brn and Brn/Yel wires of the vehicle's harness at the point where they would normally enter the igniter, OR

1.6 style coils, with the igniter installed as normal.


To be honest, using the igniter and 1.6 coils is probably going to be beneficial at this stage for the purposes of diagnosis (assuming the under-hood harness has not been hacked up) even if they're just lying on the top of the valve cover. If you're uncertain as to whether they're making contact, you can use a sharp knife to trim away the section of the boot which seals against the valve cover, thus enabling them to be fully inserted. (I've honestly never tried using '90-'00 style plug wires on a VVT valve cover.)


This is interesting.

Assuming that your MS is built to the DIY-style plans insofar as the spark driver circuit, then a single spark at power-on is expected. It's an unfortunate side-effect of how they have the circuit designed.

However, if you're not getting any action after that, then it makes me wonder about the software configuration of the MS (presupposing that you have a solid RPM indication while cranking.)

I have seen some timing lights that wouldn't work while the starter was turning, because the starter pulls the battery voltage down too low. So you can try powering the light from an external source (preferably another car battery.)


I still suggest that you at least try swapping the plug wires around, just to be sure that you haven't fallen victim to the 1.6 vs 1.8 mismatch.

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