Common problem, not an average fix. KA24 stalling

[foolycooly]

Hey guys, so I bought a 89 coupe two tone shell. Decided to do a ka24de swap into it. The car was originally automatic, and previous owner had already done the swap to manual.

To start, the KA24DE is stock. It is the s13 KA24de with the butterfly valves in the intake. Has NGK wires, new NGK plugs, EGR delete. Things I've changed are injector o-rings, thermostat and gasket, hoses, belts, front/rear mains, valve cover gasket, oil, oil and fuel filters, etc. Swapped into it a clean gas tank and fuel pump. Using automatic ECU (green number 29)

The car will run, idle at 750/800rpm in limp mode with the maf unplugged. As soon as the maf is plugged in, it will jump up to about 2000 rpm and subsequently sputter and die within 3 or 4 seconds.

I have followed everything per FSM in the EC section

ECU reads code 55 - normal operation
I have swapped ECU's. Same problem.

TPS ---- pg 121 of EC
Ohms good for sensor
Voltage good
To ECU has continuity

Coolant Temp Sensor pg 99
Ohms good (Sensor)
Voltage good
Ground good
To ECU good

MAF pg 96
Ohms good (Sensor)
To ECU good
Voltage signal readings good both with key on/engine off and running

Dizzy pg 93
To ECU good
Injectors click
When disconnecting, hear relay click on passenger side
Voltage good when spun

IACV
Removed and cleaned it (the body as well as the valve that's held on by two screws)
Ohms good

Injector resistance is normal

Power Balance Test – seemed like momentary loss of power as per FSM

Compression Test – good and even across all cylinders

Fuel Pressure – good

Timing – good (20 degrees)

Vacuum leak test – good (I made a tester that is attached to the intake pipe and connects to air compressor)

FPR w/wo vacuum – no difference

New injector O-rings

I have extra parts laying around, and swapped them just for the hell of it.
I have swapped mafs, no difference
TPS, and manually controlled with a screwdriver, no difference
knock sensor, no difference
ECU, no difference

[N/A Q45]

Usually if you unplug the maf and it runs better then that is the area you need to focus on, I just posted something on the general page about the "gas spewing from exhaust" thread about what to do to check the maf ground. But basically you need to check the grounds at the ecu with the key on and key off. But what I need to know is what the car does if you start it with the maf plugged in? Does it jump too 2k and then die? The stock mafs are pretty much junk from what I have found, could be the connector. I like the e60 mafs, better flow and seem to be easier to work with + can find them for dirt cheap.

And what kind of intake do you have on it, it may have a leak and allow unmetered air past the maf which would explain alot.

[foolycooly]

Yeah, it'll jump to 2k and die if I start with the maf plugged in, or if the car is running and I plug the maf in. I have the stock plastic intake pipe. There aren't any leaks, I made a tester that plugs into the air compressor and pressurizes everything to about 10psi to see where leaks are.

[foolycooly]

When you're saying to check the ground, are you meaning continuity between the maf plug and the corresponding pin on the ECU?

[N/A Q45]

You can't run 10psi through the intake pipe unless you block the filter side . Do you know what pipe I am talking about? And I mean check the grounds from the connector to the chassis and from the ecu to the chassis. The ecu hads quite a few grounds but they are easy to check. I'm really wondering how you have the intake set up and just in case msybe you don't have a filter on the maf ( mine use to stall and all that because theaf couldn't get the proper reading.

[foolycooly]

I know, I essentially took a piece of 2.5 inch steel tube, blocked off one side of it. Added an air fitting. And attach with hose clamp where the maf would be. Set compressor to 10psi and check for leaks. As long as motor is at TDC you'll pressurize the whole intake side. In the few seconds that it does run with maf plugged in, the maf's output signal voltage (The voltage that tells ECU the airflow) is at normal specs per fsm page 160. It read about 1.2v if I remember correctly.

My intake is set up exactly like stock, as in this picture. Using the OEM plastic pipe, maf attached to it. Whether or not there is a filter on the maf shouldn't make that big of a difference.

http://i21.photobucket.com/albums/b288/ ... inebay.jpg