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2G Hard Starts & Bad Misfire

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GofaST4life

15+ Year Contributor
2,898
132
Oct 21, 2007
Medina 44256, Ohio
What’s up everyone. I need some help diagnosing a no start / Bad Misfire – and im sorry this is so long.

Let me paint you the whole picture.

Some of you may be following my build thread, in a nut shell, I bought a used motor, a stripped shell and basically have been putting a car together for the ShootOut. So here we go.

On the weekend of the 30th (July) I was at the point where I wanted to start the motor. I threw in 5 gallons of fresh E85, turned the pump on, hit the key and she fired right up! YES! Was idling around 900-1200, I didn’t let the car run to long as it wasn’t full of coolant and only had a downpipe on it. I just wanted to see if it would start so I could move forward.

Fast forward to last weekend, Saturday the 6th, I pushed the car out into the driveway, put her way up on stands, installed the full exhaust, brake lines, rear caliper and rotors, etc, filled her with brake fluid, bled everything, filled up the coolant, replaced the tcase and rear diff fluid. Done. Yay. Got in the car to start her and nothing. Just turned over and over and over.

Decided to start diagnosing:
- No CELs
- CAS is working fine
- CPS is working fine
- Coolant Temp is fine
- Fuel is flowing through the lines
- I have spark (keep reading)

Fast forward again to yesterday:
- I pulled the return line from the pump, to make sure fuel was actually flowing, it was.
- I pulled the spark plugs, re-gapped, installed
- I pulled individual plug wires, they all seem to be firing (although I’m not 100%)

Heres the weird thing, the car was on a battery charger the whole time, battery reads at 12.9-13.3 volts. The car has a hard time cranking. I even took some jumper cables, started my Tacoma, hooked those up, AND left the battery charger on it. STILL car barely wants to turn over.

HOWEVER, when I was testing the plug wires, I heard her fire slightly. So I jump in, activated the fuel pump, hit the key, starter clicked a few times and they she SLOWELY started turning over...and started. But she has a really bad misfire, almost like she is running on 1 or 2 cylinders. RPMs stayed around 300-500, sounded not good. I got out to look at the bay, I forgot to plug one of the plug wire back in and spark was jumping at the coil pack, could see it. I plugged it back in and no change in the running condition.

Here’s what I’m thinking:

1. I may have an ignition problem, I’ll start her and pull one plug at a time until I can find out what cylinder are and aren’t firing. Then use that plug wire to test the other cylinders. This way I can rule out the coil pack or the wires themselves.

2. I think I should pull the injectors to make sure they are all firing and clean them out again.

3. Possibly drain the tank and put in all new gas. Car initially started with fresh E85, but after sitting for a week, maybe all the old gunk got loosened up and clogged my injectors/filter? (shell hadn’t been ran since 2010, no idea what was in the tank before adding the E85)

4. Check the TPS?

5. Check my ECU for possible issues?

ALTHOUGH the 3 points above don’t explain why the car wont crank properly…

Does anyone have any other suggestions or ideas?
 
Solved:

The PTU plug wasn't staying connected, I zip tied it down and not she runs fine.

As for the starting, still cranks very VERY slow, I believe I have a bad connection somewhere. ill be looking into it over the winter.
 
I would say you may have a problem with the power to the injectors if you have a set up with a 1G cast pull the cash out of the head and with the key or sit there and spend it with your finger and with your other hand on some injectors see if you feel them click and Fire.

Just because you've got fuel running through the lines doesn't mean it's getting into the cylinders also could have an engine that jumped way out of time too. But for your sake I hope that's not the case
 
Slow cranking sounds like a dying battery. Voltage is not enough to determine battery health. Sure, if it wont charge up past 8 volts and stay there, its definitely bad. Even a bad battery can show/hold 12+ volts. Letting a battery sit or discharge alot will accelerate this dying process.

I would start the car, if I was lucky. I frequently got the low battery solenoid clicks even just after charging. Threw in a new battery, and that thing cranks faster then idle RPM (not really, but compared to before, it feels like that)

If you think bad connection, check the thick wire from starter to battery, and the grounds.
 
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