Stuttering/bogging under load UNDER 2k rpm

[Danteandsoob]

I bypassed the ground wire, but not the power lead. should i do both?

[RoughDiamond]

You can backprobe the 12V feed to the pump while it's running to see what voltage it's seeing... Should be approx. system voltage, given a 0.5V or so.

[Danteandsoob]

So it got extremely cold down here in the southwest, and this morning the car wouldn't even want to start. It finally got it started and warming up and it doesn't want to go anywhere. If it revs under 1k it's just stalls. Gonna bypass the 12v lead to the pump and report back.

[Danteandsoob]

Update: just did the bypass and still no change. Should I reset the ECU?

[Legacy777]

For kicks and giggles, try unplugging the MAF sensor electrical connector.

[Danteandsoob]

While it's running? Dies.
And does not start when it's unplugged.

[Legacy777]

Ok.

If you keep cranking does the exhaust or engine smell like it's getting fuel and flooded?

[Danteandsoob]

Oh scratch that, I just tried starting it with the maf unplugged and it started. Last time I checked it did not. It ran really poorly and died when I touched the throttle.

[Legacy777]

See....that's what I wanted to find out. If it starts with the MAF unplugged, but doesn't start with the MAF plugged in then there is an issue with the MAF or MAF wiring.

Have you checked all the MAF sensor wiring & MAF with a multimeter?

http://main.experiencetherave.com/subar ... sting1.jpg
http://main.experiencetherave.com/subar ... sting2.jpg


Can you please confirm this issue is on your 93 Legacy non-turbo. Also, can you please confirm the MAF you have on there is the black bodied plastic JECS MAF.

[Danteandsoob]

Yeah, sorry if I seem like I'm being difficult or rude; I'm not trying to be.

I'm at work right now might have a chance to check here around lunch.

Yes, the issue is for my 93 N/A Legacy and it has a properly working JECS MAF.

[RoughDiamond]

Have you checked the resistance of the ECT? Just recently, I left mine unplugged while changing a hose and it didn't want to run or idle at ALL with it unplugged. Plugged it back in, no prob.

[Danteandsoob]

ECT? Engine coolant temp sensor? I have not, but I am getting a new one in the mail here soon.

[Danteandsoob]

So I tried doing the easiest thing first, resistance between MAF connector and body and it wouldn't pick up anything, am I doing something wrong?

[Legacy777]

Are you doing the third test in the second scan? If so, all but number 3 of the connector should not have any continuity with the chassis body (aka ground).

[Danteandsoob]

Okay, I guess the multimeter I was using measures 0 differently then my one at home, so that's not the issue.

So for test 1, I just turn the ignition switch to ON, and unplug the ECU Connector to test?

And for test 2, I have to somehow reach the multimeter testers to measure resistance through the entire length of harness from the MAF connector to the ECU connector?

[Danteandsoob]

Anyone know how I should this? I tried getting under there last night to meassure voltage and got no readings.

[Legacy777]

For test 1 you need to leave the ECU connector plugged in and back probe those pins the get the voltage reading. If you can't get these readings I'm less concerned about this test as it's primarily testing the output from the ECU (which we're assuming is good).

For test 2 yes, you need to reach the multimeter test leads from the MAF connector to the ECU connector. If the leads don't reach you can use a length of wire. I usually use a small gauge wire that I stick into the connector and then check the overall resistance with that wire. It's important to check the resistance of the wire you use to ensure its continuity is 0 ohms.

For test 3 you are just checking to make sure there is not a ground short in the wiring harness. So you check the resistance of the different connectors and ground. Since one of the pins (No. 3) is ground, you should have 0 ohms.

Does that make sense?

[Danteandsoob]

Absolutely, thanks josh; I will be rechecking this stuff again tonight after I get off from work.

[Danteandsoob]

Alright, so I'm not sure what any of these reading mean but here they are:

Test 1. I still couldn't get this measurement, but as you said it's okay if I don't/can't assuming the ECU is good, which I'm assuming it is because if it wasn't wouldn't it throw other sensors and stuff off..?

Test 2. No. 8 / no. 1: .2 Ohms
No. 9 / no. 4: 0 ohms
No. 10 / no. 2: .2 Ohms

Test 3. No. 1 & 4: 0 ohms
No. 2: .2 ohms (not converted to Mohms)

[Legacy777]

For test 2, the .2 ohms isn't a huge deal, it just means there is some resistance building up in the wiring.

For test 3, are you sure you did that correctly? Just to confirm you tested the chassis side wiring correct? Did you test No. 3 pin?

What your readings are saying is that there is a break in the MAF sensor wiring and it's touching the chassis/ground. I would recommend going back and redoing the 3rd test to confirm and get readings for pin No. 3.

[Danteandsoob]

Pin 3 gave me 0 ohms. sorry, I have no idea why I didn't include that one.

So I went ahead and re-did test 3 and pins 1-4 were all 0 ohms this time.

[Legacy777]

Then I would say you have a break somewhere in the MAF wiring and the wiring is touching the chassis. Try following the wiring under the engine bay and under the dash to look for any cuts/nicks in the wiring/insulation.

[Danteandsoob]

I will have to check that Josh.

So I took the car to the dealership today and even they columdt figure out what the problem was, so now I'm pretty frustrated.
I know someone on here had the same problem, and it was timing related.
Also my crank pulley wobbles, so I need to check that as well.
The car is also overheating and they said the passenger fan was not turning on. I noticed it was over heating after I replaced the radiator after it cracked.

I'm just about done with this, can anyone think of anything I might have not thought of?

[Danteandsoob]

Also, I replaced the coolant temp sensor, as most people have suggested, and I saw no improvement.

[RoughDiamond]

What about vac readings, compression numbers?

You can also see the timing marks are in agreement because on the cam pulleys, the large arrow (not the 'timing mark') will both point at ~2 o' clock when looking at the pulley with the timing mark aligned to the rear cover. I've see some people use the wrong timing mark and it will idle, but not accelerate.

I still think you've got a vacuum or vac ref issue.

EDIT: Does the engine freely/willingly rev when in neutral/park? JUST under load?