95 850 5spd... swaped the coil,cam sensor and fly wheel sensor still very little or no start/spark. Are there any other modules that may be affecting this??? At the moment i am just looking for this one i was told right front in the engine bay.... Or is it one of those 2 larger computer boards by the window washer fluid??? I have an auto fix it guy coming to look at it wensday and before he gets to it i want to do everything in my power to get it going. That way i dont have to pay Lol Thanks in advance ZR

 

Where is it you are checking for the spark at ?? Out of the coil or at one of the spark plug wire ends ??

Is the battery fully charged and sitting at 12 volts or a little over ??

have you checked the ignition wires for their resistance and visual condition ??

What are you using to make the gap for checking the spark and what are you using for ground ??

Did you use a new coil ? Know good used coil from another vehicle (know it runs) or is it a salvage yard coil /module unit ??

What does the inside of the cap look like ?? Rotor ?? If you're checking at the end of the plug wire it could be excessive resistance in the cap and rotor.

 

The plugs,cap and rotor were pretty fried so they were replaced( those are what the car was running on before all ths) We have checked at plugs and at the coil. At the coil we used the ol screwdriver in the wire trick and we used a spark plug with the same outcome...spark as the key is turned off. The coil was swapped as was the cam sensor and flywheel sensor(off a was running car. I have a whole 93 parts car tbelt went) We got it to start again as well. The only things different was that i swapped one off the computers and put a jumper from the hot on the batt to the hot on the coil. It started right up ran fine and dandy then turned it of and kaput again no start. I also took the jumper off while it was running and it stayed running. Also batt is charged Thanks for the come back Zech

 

If you only have one ECU that says BOSCH, I believe it controls both fuel injection and ignition timing. Apparently some people have two ECUs, I can't tell you anything about that. The other ECU is the transmission control; it should say AISIN.

COMPUTERIZED ENGINE CONTROLS
850 non-turbo models use a Bosch LH 3.2 multiport fuel
injection system with a EZ129K electronic ignition system with knock
sensor, and with self-diagnostic capabilities.
Vehicle uses an Electronic Control Unit (ECU) that receives
input from engine monitoring sensors. These sensors include camshaft
sensor, coolant temperature sensor, oxygen sensor, knock sensor, mass
airflow meter/sensor and throttle switch. ECU uses these input signals
to control air/fuel mixture for emission control, fuel economy and
good driveability. Ignition control is provided by a separate ignition
ECU.
CONTROL UNITS
Electronic Control Units (ECUs) provide precise control of
fuel and ignition. Each system has self-diagnostic capabilities.
850 non-turbo models use separate ECUs for fuel injection and
ignition control, located in right front of engine compartment.

 

Did you replace the coil with a new one ?? There is the module that comes with the coil that could be bad or intermittent.

 

Sorry bout this being late but been busy I did swap the coil off a running car. So.... we pull started the car... started instantly no probs. Turned it off started it ect ect left for the day. My friend tried the next day on a whim and it started up ran ruff (like it was lean he said) pushed the throtel and it smoothed out. He then turned it off and it would not start again. It was very low on gas so we got more (1/4 tank). I tried with a sniff of either notin but few seconds and another sniff later it started fine. Took it for a spin(3mi +) all functions good. Parked it started it ect ect it did seem the longer it sat the harder it was to start. So next i shall check fuel pressure and what not. However this wouldnt solve the no spark prob. We have ordered a ignition switch and a coolant temp sensor (motors alldata said it can cause a no start) as it seems to start when hot. I see some others are having hard/no start problems as well so i l will keep an eye on their threads as well and if i come up with anything ill post on their thing too. Thanks turkey... we went through every thing to the best of our ability and didnt find any thing blatant. All the best Zech R

 

Odd that it would pull start with no issues. You said you tried swapping the ECU?

I can tell you that when my coolant temp sensor was bad, it would flood and not start back up. I could pull the fuel pump fuse (#2) and it would start after cranking for a few cycles and run on the persistent rail pressure for 5-10 seconds.

 

Super noob question.......which one is the ecu.......... Lol Thanks ZR

 

It's the one(s) that says Bosch. Both my 96 cars have one ECU that handles both engine management/fuel and ignition timing, and another ECU for the transmission that says Aisin.

Some vehicles apparently have a separate ECU for ignition. I have not messed with one but I would assume both ECUs would say Bosch. My one engine ECU is in the middle slot. The slot closest to the engine bay is empty; the transmission ECU is next to the fender.

 

It will be inside the black box in the red circle.

Found this too:

Before pulling the ECU out, you need to disconnect the negative battery cable and wait 15 minutes for the power supply to dissipate. If not followed, damage may result (I had removed the ECU without waiting 15 minutes but it did not fry it, but better be safer than sorry).

 

I have popped mine out and swapped it by pulling over to the side of the road, shutting the key off, popping the hood, swapping the ECU and go drive. Never been an issue.

 

Huh..... well i did swap one as the numbers matched but the middle one i did not swap. In the box there are two ecu's one in the mid and one close to the engine. From what i gather the 2rd ecu is for the automatic tranny. I got a new ignition switch and temp sensor so i will see what that does. Thanks guys ZR