1987 MR2 MK1 Starting Problem

I recently got a 1987 Mr2 NA and i occasonly have trouble starting it sometimes, the starter engages and the engine turns over but the car dosent start... I am new to the MR2 and am looking for ideas on where to start trobleshooting.

also, there is OIL in with my spark plugs, is this normal on an MR2? The car runs verry well and dosent over heat, coolant and oil levels look right but when i pulled a plug wire i seen the stinger of the spark plug was almost covered by oil...never seen that one before.

thanks for your help.

Ok so after looking arround for a little while about the oil problem I discovered the valve cover on this car has more then one seal, went to toyota got the gaskets and installed them, had to seep up what seemed to be a qt of oil but all is good now.

still haveing a problem with starting the car sometimes, mostly if i go for a short hop, ie grocery store, when i try to start the car, it cranks but wont fire...so my temp fix is to park on hills and pop the clutch when it wont start :)

any ideas where to look for the starting problem? thanks.

Ok so i enjoy talking to my self :) LOL.

I have been reading alot since i got my mr2 and just yesterday I found out how to read the codes off the ECU. the two codes the car has stored are:

code 6, No Ne, G signal (engine revolution sensor) signal to ECU within several seconds after engine is cranked. No Ne, G signal (engine revolution sensor) signal to ECU within several seconds after engine reaches 1,000rpm.
# Distributor circuit.
# Distributor.
# Starter signal circuit.
# ECU.

code 10, No STA signal to ECU when engine is running over 800rpm.
# Main relay circuit.
# IG switch circuit (starter).
# IG switch.
# ECU.
# The vehicle has been push-started.

the code 10 i have down, i push started the car, thank god for good compression :). the code 6 is where i am kind of hitting my head on a brick wall, and im sure thats where my gremlin is hanging out,i honestly just dont know how to test for the starter signal circuit or distributor circut any ideas on where/how to start would be helpful.

I cleared out the codes in the ecu and have not had a problem starting since, i dont expect this to last but i live and work on a hill so im ok with it :). if i do get this fixed ill post how i did it :).

I haven't had the same problem but it sounds like bad wiring between the ECM and the engine revolution sensor could cause the code 6. Code 10 is probably just from push starting imo. Electronic fuel injection systems need to know the engine is turning before it will start pumping and squirting fuel. As a fail safe most will also start up the fuel system when the oil pressure climbs to a certain point ie when you crank it for a long time or push/roll start it. Without looking at my wiring diagrams I'd guess it's a bad ground or possibly a damaged wire bundle going to the ECM.

Ok got out my wiring diagrams now, I have the manual for a 1988 NA but it should be close. This is pretty long to explain but I'll try to do it without pictures...

The wire bundle you need to find runs across the engine head between the valve covers and timing belt cover on the right side of the engine (behind passenger seat). You should see a black plastic protective 'tunnel' which can be opened up to expose the wires. Coming out the dist side the wires go to the AC clutch (if AC equipped), engine compartment cooling fan, oil pressure sensor, and the distributor. Dist connectors shound be a 2 pin "a" and 5 pin "b", both green according to the manual. At least 5 wires should be going to the ECM's "U" connector, a yellow 10 pin connector.

According to my diagrams the wires for the revolution sensor are:
"G-" White wire, from ECM U#4 to a#2
"G+" Black wire, from ECM U#3 to a#1
Both wires are shielded according to the diagram so I think those are most likely wrapped in tinfoil looking material which is grounded to prevent interference. Those wires or the sensor in the distributor are the first place I would check.

From the Ignition coil/ignitor are 3 more wires:
"NE" White wire from ECM U#1 to dist b#5
"IGF" Black/Yellow from ECM U#5 to dist b#1
"IGT" Black/White from ECM U#8 to dist b#2

First find the ECM which is in the rear trunk, behind the front trim panel. Use a small screwdriver to push in the center button of the trim fasteners slightly and they should come out. The ECM is the big box in the middle with 3 yellow connectors and wire bundles going to it. Find and unplug the 10 pin connector and figure out which are the #3 and 4 terminals, which should be a black and white beside each other near the 'clip' that holds the connector together.

Get a digital multimeter (if you don't have one then buy one, you'll need it) and set it for resistance, then stick the probes into terminals 3 and 4 on the harness side, with the 2 pin distributor connector plugged in. You *should* have anything other than 0.000 or a very low number meaning a short circuit or an infiniti symbol or "OL" meaning an open circuit.

The rev sensor is an electromagnetic coil which will have resistance, the manual doesn't show a spec but lets say between 100 and 1000 ohms give or take. If you have an open that means the wire is broken and the electrons can't get to the sensor and back again, a short means the wires are connecting and electrons can get across between the wires without going to the sensor. Either way the ecm won't get a proper rpm signal and I think that will be the problem most likely.

If that part checks out ok then unplug the 5 pin at the distributor and connect the multimeter probes to either end of the NE, IGF, and IGT wires at the distributor and the ecm sides. Each wire should read 0 ohms or very low resistance between connectors. If the resistance is infiniti/OL you have a broken wire. To check for a short hook the positive (red lead) to the battery alternately + and - sides and make sure you don't get 0 ohms or very low resistance. Again this means a short to power or ground, most likely to ground through the engine block.

Any sign of problems in a wire means you have to go follow the wire through the engine compartment and look for damaged/burned insulation, exposed wire strands, or anything that could cause a bad connection ie loose or broken connection at the dist connector, or connector not properly connected. If the wiring itself checks out but there is a short or open in the rev sensor then you probably need to replace the distributor unless you can get just the sensor itself.

I hope I didn't lose you completely with all that, I went to school for a while to learn auto electrical diagnosis so I know what I'm talking about, but I don't know if that will make any sense to anyone who doesn't know a lot about those things. If you need more explanation or pictures email me and I can take pics of the wire locations and diagrams for you. Good luck :)

Well had a run of bad luck yesterday, my MR2 was totaled by my nebor, came home drunk and bulseyed my mr2 in the drivers side door, poped the hinges on the door and bent the hell out of the pillar where the hinge goes, the good news he had full coverage insurance, the bad news, they want to total my MR2...I have not decided weather or not I will keep the mr2 and part it or if i will just let them cut me a check and take it with them, i have decided i am going to buy another mr2, any one see an SC for sale let me know :).

thanks.
James