Another eta starting issue - HELP!
Vehicle:
1987 325es (eta), 185K miles.
Conforti chipped “027” DME. No other engine or electrical mods.
Symptoms:
· Intermittent no-start, which can happen with the engine either hot or cold. The starter operates normally but the car will not fire off or even attempt to fire off. It may not start for a half hour and then be fine. It may not start for days at a time, and the next day it fires off on the first try.
· Very intermittent loss of engine power. On three occasions over the past year with the engine at operating temperature, the car started on the second or third attempt but the idle speed was low. I could not drive more than 1 mile and at more than 20 mph without the engine bogging down, and the temperature gauge shot ¾ of the way up. I pulled over and turned the car off. When it cooled, it started right up and ran normally. I have a new mechanical fan clutch installed.
· The other 99% of the time, the car fires off on the first try and runs perfectly. It has never stalled, so once running it is fine.
What’s been changed over the past year:
· Main, fuel pump and oxygen sensor relays
· Coolant temperature sensors on the thermostat housing (all four)
· Spark plugs
· Intake boot, breather hose, vacuum lines, timing belt, water pump, valve adjustment, fuel filter, radiator and a whole lot of other parts not directly related to the issue I’m having.
What’s been checked:
· I did a complete check of the Motronic sensors and harness all the way back to the DME last summer. I verified all sensors were operating correctly and within ohm limits by measuring at each sensor itself and at the DME connector.
· Inspected the distributor cap, rotor, ignition wires. All are fairly new and in good condition.
· The coil passes its resistance checks on the primary and secondary side.
· All grounds in the engine compartment are tight and corrosion free.
· Fuel pressure is 32-34 psi with no loss of pressure in the rail overnight.
The issue is of course that the car runs great unless it is acting up. WHEN it acts up I don’t have my diagnostic equipment readily available to tell what is going on, so I can’t pinpoint the problem to a fuel or spark (or both) issue.
Research tells me that the two crank position sensors, the ignition switch, the fusible link in trunk or the DME itself could all be potential causes, but there’s no way of narrowing it down to one issue. Which of these should I start with?
And am I missing anything else that someone might have come across in the past? I’m getting afraid to turn the car off anyplace other than my garage!
THANKS!
1987 325es (eta), 185K miles.
Conforti chipped “027” DME. No other engine or electrical mods.
Symptoms:
· Intermittent no-start, which can happen with the engine either hot or cold. The starter operates normally but the car will not fire off or even attempt to fire off. It may not start for a half hour and then be fine. It may not start for days at a time, and the next day it fires off on the first try.
· Very intermittent loss of engine power. On three occasions over the past year with the engine at operating temperature, the car started on the second or third attempt but the idle speed was low. I could not drive more than 1 mile and at more than 20 mph without the engine bogging down, and the temperature gauge shot ¾ of the way up. I pulled over and turned the car off. When it cooled, it started right up and ran normally. I have a new mechanical fan clutch installed.
· The other 99% of the time, the car fires off on the first try and runs perfectly. It has never stalled, so once running it is fine.
What’s been changed over the past year:
· Main, fuel pump and oxygen sensor relays
· Coolant temperature sensors on the thermostat housing (all four)
· Spark plugs
· Intake boot, breather hose, vacuum lines, timing belt, water pump, valve adjustment, fuel filter, radiator and a whole lot of other parts not directly related to the issue I’m having.
What’s been checked:
· I did a complete check of the Motronic sensors and harness all the way back to the DME last summer. I verified all sensors were operating correctly and within ohm limits by measuring at each sensor itself and at the DME connector.
· Inspected the distributor cap, rotor, ignition wires. All are fairly new and in good condition.
· The coil passes its resistance checks on the primary and secondary side.
· All grounds in the engine compartment are tight and corrosion free.
· Fuel pressure is 32-34 psi with no loss of pressure in the rail overnight.
The issue is of course that the car runs great unless it is acting up. WHEN it acts up I don’t have my diagnostic equipment readily available to tell what is going on, so I can’t pinpoint the problem to a fuel or spark (or both) issue.
Research tells me that the two crank position sensors, the ignition switch, the fusible link in trunk or the DME itself could all be potential causes, but there’s no way of narrowing it down to one issue. Which of these should I start with?
And am I missing anything else that someone might have come across in the past? I’m getting afraid to turn the car off anyplace other than my garage!
THANKS!
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