The Racecar Needs Your Help! Options

[turbohcar]

I have been having trouble with this beast for almost a year now and no result has come of it. My friend and I have built a Hornet/Wild Thing racecar for the dirt circle. It's a 91 N/A (turbos and AWD aren't allowed) 5spd 2.0 4G63. Now, we bought it from some hillbillys in Ohio that had a Mitsubishi graveyard. The car came in stock condition minus an ECU. We thought, throw a good ECU in and we're good to go.....Wrong! After two ECUs, eight spark plugs, four plug wires, two coil packs, two transistors, two CASensors, two MAFs, four injectors, a fuel filter, a battery, a fuel pressure regulator, and misc. other things this thing still doesn't run correctly.

Finally, it's warm enough to do some work and Spy graciously let me borrow his logger to finally get this thing figured out. Here's the log I came up with. All of these are done with the gas to the floor. It cuts out around 5k RPM and acts like fuel cut. Sometimes it does this when climbing in RPM too but really only cuts out at 5k (on the stock tach).


RPM 4343
INJP 11.77ms
KNCK 0 (I don't think the N/As have a knock sensor)
TPS 99.6%
INJD 42.1%
TIMA 21*
02F 2.48V
COOL 85.6*C
AIRT 28.6*C
EGRT -28.2*C
BATT 13.0V
ISC 23.4%
MAFS 855.4Hz
ACLE 0%
02R 0.66V

Here's another

RPM 3312
INJP 11.26ms
KNCK 0
TPS 99.6%
INJD 30.4
TIMA 22*
02F 2.48V
COOL 87.5*C
AIRT 30.0*C
EGRT -28.2*C
BATT 13.2V
ISC 23.4%
MAFS 610.1Hz
ACLE 0%
02R 0.78V

Please help. If you've got any ideas let me know. I did notice that injector duty is incredibly low and don't know how to explain it. Thanks for any help tuners.

[turbohcar]

I finally got it home from its former residence in the storage unit. For whatever reason, now it doesn't even want to start. I've got spark, but it appears weak (not as strong as it should be) and the plugs come out black. These are brand new plugs and they come out pitch black. Oil consumption is most likely the cause but, I can't see how it could affect it this seriously. I've tried putting a spare ECU and CAS (the CAS and ECU were junk, no reading on the datalogger) I had on it but get no result. Pretty soon I'm going to start transplanting parts from my turbo car onto just to see what works. I've got 99 problems and a b!tch is one.

[ncgalant]

Have you checked to make sure the valve timing is correct? What about the base ignition timing? Also, log O2 rear, that's the front one.

[natedogg]

1G's only have 1 O2 sensor. 2.48V is a tad high for a narrow band O2 sensor. It should only read between 0 and 1 volts. Have you tried replacing the O2 sensor?

[turbohcar]

I added the 02R log to the data at the end. I was thinking that same thing to myself Nate until I saw a difference in the values, so I posted them regardless. Dan and I uploaded the MMCd software that NC Galant suggested.

When I turn the car over it has a base reading of 5*. At idle it's set at 27*. Keep in mind, I didn't make that setting. He had another friend set the timing for him with a timing light.

I have not tried replacing the 02 sensor yet but have thought about it. I didn't think that it would make that big of a difference as far as the rough mixture. I guess I thought it was just for the finer mixture to compensate for outside temperature and altitude.

Excuse me for my unrefined diagnostic skills but exactly how do you check valve timing as opposed to timing advance?

The spark plugs are now sparking inside themselves. As in, they are not sparking at the point, it's down inside between where the plug threads into the head and the base of the projected point. I even took the plugs out of my turbo car that were in good, new condition and it even ruined those ones.

There is also an incredibly loud audible sound coming from the top end of the motor. The top end doesn't sound quite like the precise, calm sewing machine it's supposed to. More like a sewing machine over-juiced on steroids going too fast and hammering itself into oblivion. I'm not sure if this has anything with the valve timing possibly being off but it's a thought.

[natedogg]

The quick and dirty way to check the valve timing is to just pop off the upper cam gear cover and check the timing marks at cyl 1 top dead center. Make sure the marks on the gears line up next to each other and make sure the dowel pins on cams through the gears are both pointed up.

[grimy4]

While you have that cam gear cover off you may want to check the CAM itselef!!
It could have a rounded lobe on it !!

[ncgalant]

Another thing I was just thinking of was to make sure the head is good and grounded. Perhaps its just a spark issue.

[Mitsu 77]

The engine runs fine untill just a little over 4600. I would almost bet that it's not an engine problem. Valve timing was fine when I checked it, did you check the fuel pump like I told you to last year?

[turbohcar]

I haven't had a chance to jack it up to check the fuel pump yet. Valve timing is fine, I checked it last night. I've got an extra ground strap that I can bolt on tonight.

Even if it is a fuel pump problem, it shouldn't be fouling plugs like it is.

[ncgalant]

actually it reminds me of what my escort did with a bad alternator. Make sure you have > 14v with the car running.

[turbohcar]

Actually, ^^^the logs above show that it's only getting about 13volts. I have been charging the battery lately but when I went to pick it up it was dead and I had to jump it and even then I had to let it sit for awhile before it would turn over. It makes me wonder.....

[turbohcar]

Grounded the head tonight...no dice. I just noticed that when I lined up the cam timing marks dowel pins in the cams are pointed down. Nate, what does this mean?

[natedogg]

Probably just means either your #1 cyl isn't in TDC pos. Or maybe it is but in the wrong stroke. You should be able to line up the marks with the dowel pins pointing straight up and your crank and oil pump markings should line up. (You'll have to remove the lower cover to check these.)

[turbohcar]

Well, I've ran into a really strange situation. I went ahead and lined up the cam gear timing imprints again. This time, I found that the set of cam gears that are on this car, have two sets of imprints. One on each side 180* from each other on each cam gear. I made sure that the dowel pins were straight up and lined up the marks accordingly. I'm still trying to find a vfaq on how to make sure the piston is at TDC as I have forgotten this valuable information. I did do a quick chec with a screw driver and #1 is definitely farther up than #2.

[turbohcar]

Oh, and, I plugged a spare, brand new plug into the wires and grounded it to the valve cover just for fun. Spark in the new plug is very evident and defined, like it should be. I did notice that it was jumping around quite a bit though. I'm not sure if it's a good or bad thing but, it was sparking at the electrode correctly but was jumping around on the pickup quite a bit.

I'm sure it's probably nothing but I figured I'd add that in to cover all aspects.