1996 Mitsubishi Eclipse engine will crank but not start

Tiny
CRAZYDRIVER843
  • MEMBER
  • 1996 MITSUBISHI ECLIPSE
Electrical problem
1996 Mitsubishi Eclipse 4 cyl Front Wheel Drive Manual

I am having an issue with the ignition with my car it is an eclipse rs n/t. I have just recently replaces the trans. And rebuilt the top end. After being put back together it ran better than when I bought it for a day and a half. I was driving to go fill up when the car suddenly died and would not start back up. The engine with turn but will not start. There is plenty of fuel getting to the injectors I have check by the schrader valve on the fuel rail. Fuel will squirt out over the engine and out the car. The timing belt is very new and timing is dead on, this car has an interference engine. I have check the coil against the spec. In a repair manual and found that it tested good and bad by the book. I had tried a new coil and still the same issue. I visualy checked over the wiring in the main harness and have found no cut or grounded out wires. I hooked up a scanner and was not getting a crank reference for the crank sensor. I replaced the crankshaft position sensor and had to use a pig tail. I wired up the connector just the way the factory one was wired. I am still getting the same issue. I am in the process of back probing all the sensors that would lead to a no spark and starting issue. I have asked a friend that works for a dealership about this and have gotten some feedback all leading to a short somewhere in the wiring. I have not heard of an ecm to fri while driving.
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Saturday, March 13th, 2010 AT 5:00 PM

21 Replies

Tiny
CARADIODOC
  • EXPERT
Both the camshaft and crankshaft position sensors are supplied with 8.0 volts on their yellow wires. That's terminal # 1 on both connectors.

Ground wires appear to be black with a green stripe, (B-G), (I have a hard time with Mitsubishi wiring diagrams). They should have close to 0.2 volts. That's terminal # 2.

Terminal # 3, (L-W) is the crankshaft sensor's signal wire. Voltage should pulse between 0 and 5.0 volts during engine cranking.

The camshaft sensor's signal wire is "L-R". No idea what color "L" is.

If either sensor is unplugged, its signal wire should go to 5.0 volts.

If you find the 8.0 volt supply missing to only one sensor, suspect a broken wire, commonly at the splice. If it's missing at both sensors, there could still be a broken common feed wire, or that circuit could be shorted to ground. If a short is located and removed, the ignition switch must be turned off and back on for the 8.0 volts to come back. When that line is shorted, the Engine Computer shuts the supply down to protect it. It won't turn back on until the ignition switch is cycled.

A shorted 8.0 volt line can also be determined with an ohm meter, but the ignition switch must be turned off.

Caradiodoc
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Saturday, March 13th, 2010 AT 6:18 PM
Tiny
CRAZYDRIVER843
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I have gone back and have tested the crank, and the cam sensors for voltage. All of this is with the ignition on and not cranking. Here is what I got with the ignition turned on I get 8.0v to both cam and crank supply wires. With the ignition off I got.002v to both supply wires. The cam signal wire with ignition on 4.25v and the crank with ignition on 4.25v. I tested the coil wires with the ignition on and cranking I got no voltage to any wires at all and there are 3 different colored wires none having a common wire with the crank, cam sensor. The color wires are as follows #1 blk w/blue line, #2 black w/red line, #3 solid lt. Brown wire. I have tested all 3 of these wires at the ECM computer and did not get any voltage. Could this be due to a shorted out wire and if so where could a possible location be. Would this be a messed up ECM or possibly a relay that is bad somewhere?
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Tuesday, March 16th, 2010 AT 12:43 AM
Tiny
CARADIODOC
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Nope, when you're working with the coils, you're in a different circuit. Voltage for the coil(s), injectors, alternator field, and fuel pump or pump relay comes through the Automatic Shutdown (ASD) relay. The Engine Computer turns the relay on when it gets pulses from the cam and crank sensors. So, check for voltage at the coil while a helper is cranking the engine.

Caradiodoc
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Tuesday, March 16th, 2010 AT 2:00 AM
Tiny
CRAZYDRIVER843
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What should the spec. Be for the primary and secondary coil. I tested it and what the repair book said that I got from advance stated that it was both good and bad. I can't remember what I got but one of coils teasted weak. I replaced it with a new one from advance and it didn't start. This is what I first thought was the problem. So I took it back thinking mine was still good.
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Tuesday, March 16th, 2010 AT 1:08 PM
Tiny
CARADIODOC
  • EXPERT
Forget about the coils. In a previous test, you said there was no voltage to them during cranking. If that is still correct, the Automatic Shutdown (ASD) relay isn't turning on. That will be related to the crankshaft position sensor or the camshaft position sensor. If those signals are missing, the Engine Computer turns the ASD relay off and there will be no voltage to the coils, injectors, alternator field, and fuel pump.

Caradiodoc
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Tuesday, March 16th, 2010 AT 3:30 PM
Tiny
CRAZYDRIVER843
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I have gone thru the whole main harness and traced all the wirs to find any nicks or anything that would cause a short. Everything is now hooked back up and I have found that when cranking there is only good blue spark from the #2, #3 spark plugs and nothing from #1, #4 plugs. Would this be the coil pack now that is bad? I have tired a new coil pack before but when it wouldn't start I brought it back to get my old one and that is what is on it now.
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Wednesday, March 17th, 2010 AT 4:26 PM
Tiny
CARADIODOC
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If you have two individual coils, try switching them, then see if the same coil fires. If they are both in one assembly, try switching the two control wires, then see if the other coil fires. That will tell if it's the coil or the control wire.

This symptom sounds very much like what can happen with a Dodge Neon with the single overhead camshaft. The dowel pin between the camshaft and sprocket breaks, and the sprocket turns on the cam a little. That can be just enough to partially shut the system down to where only one of the two coils fire.

Caradiodoc
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Wednesday, March 17th, 2010 AT 4:52 PM
Tiny
CRAZYDRIVER843
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When I rebuilt the topend I never took the cam sprokets off I left them all together and took off the timing blet cover with i.T Where would the pin be located for this? As mine is dohc. The coil pack only has one connector going to it and the coil is a sealed unit.
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Wednesday, March 17th, 2010 AT 6:15 PM
Tiny
CRAZYDRIVER843
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I replaced the coil pack and I am now getting spark frome each plug now. Still the engine will not start it will just crank. Should I now start to look at the injectors for an issue or possably fuel. I did change the fuel filter befor it died, iabout 15-20 miles. Could you tell me what would cause spark out of order, or the injectors to pulse out of order.
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Wednesday, March 17th, 2010 AT 7:03 PM
Tiny
CARADIODOC
  • EXPERT
The pin for the cam sprocket is not something you would have caused. Hope I didn't leave you with that impression. That only applies to the single cam engines.

Happy to hear you have spark now. Injectors out of order would still allow the engine to run. Fuel would still get into the engine. Check for fuel pressure. The pump might not run unless the engine is being cranked. Look for a fuel pump relay. You can bypass it with a piece of wire or by removing the cover and squeezing the contact. If the pump runs this way, but not during cranking, look again to the cam and crank position sensors. You may need to measure on their wires for the voltages.

If the pump does run during crankiong, wait a minute, then measure fuel pressure to see if it is bleeding down.

Caradiodoc
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Wednesday, March 17th, 2010 AT 7:13 PM
Tiny
CRAZYDRIVER843
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I have found thst the injectors are not spraying. I have tested thenjectors and they sre good. Would you think the cam sensor is bad? I did find out that the fuel pump, MFI relay are the same I did switch them to see if that could be the problem. That didn't make any change.
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Thursday, March 18th, 2010 AT 3:00 PM
Tiny
CRAZYDRIVER843
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Iv taken the fuel rail off and whatched the injectors pulse. When you first start cranking and keep cranking with out stopping. All 4 pulse then 1, 3 and then 3 and 3 will keep pulsing. I replaced the cam sensor and still the same thing. I talked to someone about this and they found out that the injector driver is bad in the computer. Can this be flashed to fix the problem. Or does the computer have to be replaced?
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Thursday, March 18th, 2010 AT 6:52 PM
Tiny
CARADIODOC
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Well, I'm happy to hear you may have found a solution, but not so happy if it's going to cost a bunch.

Injector and coil drivers are high-power switching transistors. When they short, it's a permanent failure. Sorry, but the only fix is to find a different computer or send yours to be repaired. I would recommend finding one in a salvage yard. If you have a "Pick-A-Part" or "Pull-A-Part type yard, a replacement computer should be less than 40 bucks.

Caradiodoc
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Thursday, March 18th, 2010 AT 9:41 PM
Tiny
CRAZYDRIVER843
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Would you suspect the computer to be at fault? With the injectors mispulsing. Or could there be something else causeing this that I haben't replaced yet?
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Friday, March 19th, 2010 AT 3:52 PM
Tiny
CARADIODOC
  • EXPERT
The injector drivers are inside he computer. As long as there is 12 volts to one wire of each injector during engine cranking or running, the drivers ground the second wire of each injector to make them pulse. There's nothing in that circuit between the computer and each injector but the wire.

Caradiodoc
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Friday, March 19th, 2010 AT 7:09 PM
Tiny
CRAZYDRIVER843
  • MEMBER
Could there be something else that would cause this issue? What circuit should I look in?
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Sunday, March 21st, 2010 AT 12:14 AM
Tiny
CARADIODOC
  • EXPERT
Lets back up a minute and double-check a few things. Do you have good spark from both coils? And does the fuel pump run during engine cranking? If you have fuel pressure and spark, that just leaves the computer not firing the injectors. Double-check that one wire on each injector has full battery voltage during cranking. That will be around 10 - 11 volts.

By the way, the computer won't work properly if it isn't grounded. Run a jumper wire from it to the mounting bracket or battery negative cable if it isn't bolted into its bracket.

Caradiodoc
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Sunday, March 21st, 2010 AT 2:56 AM
Tiny
CRAZYDRIVER843
  • MEMBER
I do get voltage from all the injectore while cranking. I replaced the coil and get spark from all plugs too. I replaced the computer, I found one at a good price but still the same isssue. Something is activeing the asd relay I think. I can't seem to find out what is causing that. Do you know if there is something on the side of the crank shaft that the crank sensor uses to pick up location refference?
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Saturday, March 27th, 2010 AT 6:37 PM
Tiny
CARADIODOC
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Sorry for the delay in replying. My Verizon e-mail service is down for maintenance going on two days now. I am not receiving automated messages that you posted another comment. Hopefully that will be fixed soon.

If you have spark, the ASD relay is turning on properly. He sends voltage to the coils, injectors, fuel pump or pump relay, and alternator field.

Look for a separate fuel pump relay. If you have one, pop the cover off and reinstall it, then watch if it clicks while a helper cranks the engine. If it does not, we need to figure out if the camshaft position sensor and crankshaft position sensor are working. Normally they must both be working for the ASD relay to turn on.

Caradiodoc
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Sunday, March 28th, 2010 AT 8:33 PM
Tiny
CRAZYDRIVER843
  • MEMBER
I have just thought about checking thwe timing again. I did a visual check it appeared to still be correct at the cams, there is an access cover that can be removed. I really couldn't check if the crank was lined up due to the timing cover being in the way of the mark on the sprocket. I am taking all of that apart to double check because if that is not the problem I am having the care towed to the dealer for more indepth diag. My questioon is, is it possable for the timing to be off on the intake cam by half a notch to cause the car not to start. And is it possable for the timming to be off a little bit but not enought to cause any problems to bend a valve or cause any internal damage. I have noticed the ideler pully is broken/worn out the belt is not sitting on it where it should be but is not off it. I was thinking that the hydrolic tensioner may not be putting proper tension on the tnsioner pully. And could have cause the intake cam to be off a little. I have turned the engine by hand and by key and felt no resistance or any noise to indicated internal damage I know the 420a engine is an interference engine.
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Friday, April 2nd, 2010 AT 2:29 PM

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