I hate to do this. another, "my car is dong weird stuff"

XR4Ti / Sierra / Sierra Cosworth Discussions - Questions, problem resolution, general talk, technical tips and modifications.
Post Reply
catapultkid
Level 5
Level 5
Posts: 521
Joined: Thu Apr 26, 2012 8:04 am
Location: Richmond, VA

I hate to do this. another, "my car is dong weird stuff"

Post by catapultkid » Fri Mar 28, 2014 7:41 am

Just got the car back on the road after 6 months of fiddling. Now something new has arose and I will try to be as precise as possible in describing what keeps happening.

Last night a friend and I went for a drive to tune the fuel tables. 35 minutes later we stopped at a gas station, I left the car running and within two minutes it died on the spot. No drama, just idling at a nice smooth 900-1000 rpm then hiccuped to death in the parking lot.

We tried restarting it but the starter just clicked. Like the battery was dead.

Next we jumped it, I knew I had been having starter/voltage issues so my wife in another car followed us. It cranked just fine but no start. Just sat and cranked and cranked.

Waited less than 5 minutes with the jumpers still attached. Crank and it immediately came back to life. Thought we were ok so I took the jumpers off and closed everything up.

Started to drive out of the parking lot. Went lean and died, same issues as before. We could always see the car going lean on my wideband before dying completely.

Tried restarting without a jumper cable, it crank and crank but no start.

Waited another 5-10 minutes. This time it just clicked and we jumped it. It started right up.

Before setting off we watched it run for a few moments. It started getting really lean and hunting for idle, surging around a bunch. We could hit the gas to keep it alive but eventually it did the same thing. Died.

We got it towed home. End of last night.

Because I have an event on Saturday that I really would like to make, I wanted to hear everyones options to clear this up. To me on the outside it is obviously losing fuel. This means pump (walbro 255) or injectors are loosing current. There could be a big drain on the battery but I'm having a hard time finding it. No smoke, no other indication on the Megasquirt that anything is abnormal. Are there any common issues like this that google hasn't led me too. I was thinking fuel pump failing, or inertia relay failing, something with fuel. The starter issue may be separate so I wouldn't focus on that too much.

-Paul

Car in question below.

Image
-Paul
'85 Merkur XR4Ti
K20, VW mk2
'89 K2500, 6.0 swap
'00 Honda Insight

xr89
Level 2
Level 2
Posts: 101
Joined: Wed Feb 29, 2012 10:06 pm
Location: Wilmington, Ma

Re: I hate to do this. another, "my car is dong weird stuff"

Post by xr89 » Fri Mar 28, 2014 9:25 am

Dont know too much about MS, but to me that sounds like it could be electrical. Had very similar symptoms with my truck (almost identical except for the hiccuping) and it ended up being the neg battery cable. Truck couldnt keep the pump running.

Those cables can cause a lot of weired problems, just a thought.
My car is just like my girlfriend...
loud and temperamental.


Ben

catapultkid
Level 5
Level 5
Posts: 521
Joined: Thu Apr 26, 2012 8:04 am
Location: Richmond, VA

Re: I hate to do this. another, "my car is dong weird stuff"

Post by catapultkid » Fri Mar 28, 2014 10:21 am

xr89 wrote:Dont know too much about MS, but to me that sounds like it could be electrical. Had very similar symptoms with my truck (almost identical except for the hiccuping) and it ended up being the neg battery cable. Truck couldnt keep the pump running.

Those cables can cause a lot of weired problems, just a thought.
I am in agreement. For 30 minutes or so the car runs perfect. No issues. Then, maybe when things get warm? I start having problems. On that note.

The battery is rear mounted. With a cable attached to the frame. Then a small 10 gauge wire run with the positive to connect/balance the rear frame attachment for ground and the front. The front ground goes through several cables and eventually to the block of the motor on the passenger side. It could be the crappy ground at the front of the car as it is layered up a few times with different levels of sheet metal.
-Paul
'85 Merkur XR4Ti
K20, VW mk2
'89 K2500, 6.0 swap
'00 Honda Insight

catapultkid
Level 5
Level 5
Posts: 521
Joined: Thu Apr 26, 2012 8:04 am
Location: Richmond, VA

Re: I hate to do this. another, "my car is dong weird stuff"

Post by catapultkid » Fri Mar 28, 2014 3:04 pm

Ok here is something.

I tested the "vpwr" circuit (pin 37/57 on ecu and at many of the sensors) and even when the key is off/out there is a constant 5v source. This should not be the case. When the key is switched on. It is corrected to 12volts as it should be.

Any suggestions as to how that circuit is getting feedback like that?
-Paul
'85 Merkur XR4Ti
K20, VW mk2
'89 K2500, 6.0 swap
'00 Honda Insight

User avatar
In XS 7
Level 7
Level 7
Posts: 1545
Joined: Tue Feb 21, 2012 1:29 am
Location: Kewanee, IL

Re: I hate to do this. another, "my car is dong weird stuff"

Post by In XS 7 » Fri Mar 28, 2014 3:49 pm

I am just guessing here but, it is not something like to keep data in the memory? in other words so the memory don't get erased? :cheers
Miguel.
89 XR4Ti Monique; Waking up a real "Night/Mare-Coor".
T5, NPR IC, PIMP ECU, Walbro 255, Dual piston BOV, Manual BC, 3" exhaust, One piece Aluminum drive-shaft, mc2 LSD, Boport 1.5 cam, Ported and polish head, big valves, 80# injectors, Bob's log, (soon HY35).

sabre
Level 1
Level 1
Posts: 94
Joined: Fri Oct 15, 2004 1:31 pm
Location: Dallas, Tx

Re: I hate to do this. another, "my car is dong weird stuff"

Post by sabre » Fri Mar 28, 2014 5:09 pm

gotta withdraw my response, it only applies to the factory eec system

User avatar
turboxr4
Newbie
Newbie
Posts: 30
Joined: Mon Oct 17, 2005 8:23 pm
Location: NY

Re: I hate to do this. another, "my car is dong weird stuff"

Post by turboxr4 » Fri Mar 28, 2014 7:07 pm

Try pulling fuses one at a time while you monitor that circuit and see which circuit is pulling the 5v. Then go from there!

catapultkid
Level 5
Level 5
Posts: 521
Joined: Thu Apr 26, 2012 8:04 am
Location: Richmond, VA

Re: I hate to do this. another, "my car is dong weird stuff"

Post by catapultkid » Fri Mar 28, 2014 7:50 pm

Pulled every fuse and relay. Every sensor as well. The 3-5v is still present. Im at a loss. Found other unknown about wiring issues but not this.

Where the crap is the fuel pump relay?
-Paul
'85 Merkur XR4Ti
K20, VW mk2
'89 K2500, 6.0 swap
'00 Honda Insight

User avatar
turboxr4
Newbie
Newbie
Posts: 30
Joined: Mon Oct 17, 2005 8:23 pm
Location: NY

Re: I hate to do this. another, "my car is dong weird stuff"

Post by turboxr4 » Fri Mar 28, 2014 8:52 pm

Fuel pump relay is in main fuse box, look under cover on markings to locate.

catapultkid
Level 5
Level 5
Posts: 521
Joined: Thu Apr 26, 2012 8:04 am
Location: Richmond, VA

Re: I hate to do this. another, "my car is dong weird stuff"

Post by catapultkid » Fri Mar 28, 2014 9:05 pm

Thanks guys. I found that same link shortly after on my phone.

New test reveals that the 3-5v source must be from the ecu. Once I pull the ecu it goes away completely.

Going to test each pinout next.
-Paul
'85 Merkur XR4Ti
K20, VW mk2
'89 K2500, 6.0 swap
'00 Honda Insight

User avatar
merk23literturbo
Level 7
Level 7
Posts: 1520
Joined: Sat Feb 08, 2003 10:11 am
Location: Phila, PA.
Contact:

Re: I hate to do this. another, "my car is dong weird stuff"

Post by merk23literturbo » Fri Mar 28, 2014 9:09 pm

Pictures, projects and cool stuff here: http://tinyurl.com/psyuhej
German engineer: We custom fit every part in the Porsche engine.
Japanese engineer: You mean that you make every part wrong to begin with?

catapultkid
Level 5
Level 5
Posts: 521
Joined: Thu Apr 26, 2012 8:04 am
Location: Richmond, VA

Re: I hate to do this. another, "my car is dong weird stuff"

Post by catapultkid » Fri Mar 28, 2014 9:13 pm

All pimp inputs and outputs have voltage. Small voltages even though the key is not on. Is this normal?
-Paul
'85 Merkur XR4Ti
K20, VW mk2
'89 K2500, 6.0 swap
'00 Honda Insight

User avatar
turboxr4
Newbie
Newbie
Posts: 30
Joined: Mon Oct 17, 2005 8:23 pm
Location: NY

Re: I hate to do this. another, "my car is dong weird stuff"

Post by turboxr4 » Sat Mar 29, 2014 8:17 am

It shouldn't, if your alternator is charging properly while engine running than maybe you can temporarily disconnect battery when you shut down so it doesn't drain the battery. Check the charging voltage at the battery and see if it is around 14v, if not than maybe you can raise idle to compensate especially if you have an under drive crank pulley. I had a similar issue with my Electromotive TEC3, stand alone systems need the voltage in order to work properly.

catapultkid
Level 5
Level 5
Posts: 521
Joined: Thu Apr 26, 2012 8:04 am
Location: Richmond, VA

Re: I hate to do this. another, "my car is dong weird stuff"

Post by catapultkid » Sat Mar 29, 2014 6:00 pm

Wow. Nailed it. Ive been searching all afternoon for a stock alternator. This one has died...
-Paul
'85 Merkur XR4Ti
K20, VW mk2
'89 K2500, 6.0 swap
'00 Honda Insight

User avatar
turboxr4
Newbie
Newbie
Posts: 30
Joined: Mon Oct 17, 2005 8:23 pm
Location: NY

Re: I hate to do this. another, "my car is dong weird stuff"

Post by turboxr4 » Sat Mar 29, 2014 8:30 pm

Glad you figured it out! Make sure you connect the new one with a nice size cable to battery.

Post Reply