1979-1993 & 94 Conv [Subscribe to Daily Digest] |
Double check everything. Are the paperclips used to bypass various components (ign amp relay, over boost switch) still in place? Btw, male spade connectors on both ends of a short piece of 14 or 16g wire = better/safer.
The next time she won't start, take it by the numbers:
- Got spark? Have an extra lead & plug ready ahead of time. Good spark? A "good" spark will be be blue & able to jump a very wide electrode gap. Weak spark can be caused by a bad Hall component, out of spec coil or spark plug leads. Test your wires & the coil. Test the coil under both running & no start conditions. Keep an extra coil on hand.
- Got fuel? You stated that fuel delivery volume is up to snuff, but the next time the engine won't start, check for pump voltage per Bentley & have a helper listen for a nice hummmm. The pump won't run unless the ECU is receiving a signal from the distributor that the engine is turning over, so verify pump operation while cranking. If the pump isn't on while cranking (but is known to function otherwise), the problem lies w/the Hall sensor or it's wiring. Given that you have a known good distributor/Hall sensor, focus on the wiring. Check the ground wire at the pump is good (something like zero ohms). Pull the injectors to test for proper output & spray pattern as per Bentley. Baring a pressure check, try replacing the FPR. This is cheap & easy - go grab a salvage yard 3.0 bar unit & have someone mod the APC w/a resistor kit...why not?
- Any air leaks? A loose intake duct boot can cause all sorts of problems. Inspect all rubber couplings for cracks...these can be hard to spot. Under different conditions, the same crack may be so minute it will be nearly impossible to detect...then totally open up when least opportune.
I'm pretty sure the main computer (ECU) is only a problem/weak item on 1989 models...but I could be wrong.
Since the car now runs after installing a "new" distributor, the problem may well be solved. The fact that the car didn't start immediately after replacing the distributor could be explained as there being no fuel pressure caused by the old distributor. I would still be on guard (& make sure your gold AAA membership is up to date), but unless the no start condition reoccurs, just make sure any other potential problems are addressed - ie, ck the plugs, wires, cap/rotor, filters. As for the high RPM stumble, check the coil & those injectors. Pour a big bottle of Techron into the tank. Run it until completely empty (or at least 30mi aft the low fuel light comes on) before the nxt fill up...otherwise add another bottle, or the appropriate portion of one.
For piece of mind, take the OLD distributor out to the car & test it's Hall sensor for proper output. This is a simple matter of disconnecting the pigtail from the dist on the car, plugging it into the old distributor & taking a reading at ctrl unit terminals 3/6 while sloooowly turning the dist shaft (ign on). Be careful not to contort the Hall sensor wiring from it's natural position...or SNAP!
Despite what Bentley says, a good reading will be something more like .04v (shutter window open over sensor) to 8v (shutter wheel blocking the sensor) - CONSISTENTLY. If the thing reads fine, repeat the test, but try {gently} wiggling the pigtail connection & apply a little "stress" to the distributor w/some semi-restrained whacking & heat (heat gun - [hot,hot,hot - careful!!!] or a hair dryer set on "singe"), do NOT use a torch (for you Brits - that's not a flashlight...I'm talking propane). A helper is helpful. Assuming the replacement distributor came off a running car, it's ok to test it for a base reading (more difficult installed), but don't abuse it as described above!
Regardless of how the old distributor tests, it's sensible to rebuild it w/a Hall sensor kit.
posted by 72.87.11...
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