87 n/a hard / slow start after sitting...recording inside
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87 n/a hard / slow start after sitting...recording inside
I have an 87 n/a which has developed an annoying slow start condition a couple months back. It's almost like the circuit which does the high revving during initial start is dead.
here's a 1mb recording from this morning using my pda - I'll do a clearer one tomorrow with my camcorder: http://www.filehosting.cc/download.php?id=CC0D5B45
Whether it's first thing in the morning or after sitting a couple of minutes, the car will crank and slowly fire up - its climbs in rpm's till it gets to idle with a bwap-bwap-bwap-bwap-bwap-bwap. After a min or two of running, the idle picks up about a hundred rpm's gets it's normal bap-bap-bap-bap-bap-bap sound back.
During this time, there's some condensate out the tailpipe and it smells like an older premix outboard motor on a boat. If I give it a little gas to say about 3k rpm, it'll work out the problem faster, sometimes backfiring all the way to 3k. Today it gave a little one (as you may hear) without touching the pedal.
Once it works out the problem, the car is fine; runs smooth and strong, idles normal.
the pulses are smooth, strong and equal, power is strong on it's 35k mile rebuild so I strongly doubt it's compression related. I am seriously leaning toward something electrical but honestly am at a loss.... leaky injector, ecu, some sensor, coolant seal leak, apex seals? The injector electrical connectors are brittle - could they cause it?
I already swapped out both coil packs with some good working spares, changed plugs. Have no obvious vacuum leaks, even swapped out tps. Please help if you can guys. Thanks ~Rich
(btw, that metal tapping sound in the very begining is me banging on the starter... the new one is in the mail! lol )
here's a 1mb recording from this morning using my pda - I'll do a clearer one tomorrow with my camcorder: http://www.filehosting.cc/download.php?id=CC0D5B45
Whether it's first thing in the morning or after sitting a couple of minutes, the car will crank and slowly fire up - its climbs in rpm's till it gets to idle with a bwap-bwap-bwap-bwap-bwap-bwap. After a min or two of running, the idle picks up about a hundred rpm's gets it's normal bap-bap-bap-bap-bap-bap sound back.
During this time, there's some condensate out the tailpipe and it smells like an older premix outboard motor on a boat. If I give it a little gas to say about 3k rpm, it'll work out the problem faster, sometimes backfiring all the way to 3k. Today it gave a little one (as you may hear) without touching the pedal.
Once it works out the problem, the car is fine; runs smooth and strong, idles normal.
the pulses are smooth, strong and equal, power is strong on it's 35k mile rebuild so I strongly doubt it's compression related. I am seriously leaning toward something electrical but honestly am at a loss.... leaky injector, ecu, some sensor, coolant seal leak, apex seals? The injector electrical connectors are brittle - could they cause it?
I already swapped out both coil packs with some good working spares, changed plugs. Have no obvious vacuum leaks, even swapped out tps. Please help if you can guys. Thanks ~Rich
(btw, that metal tapping sound in the very begining is me banging on the starter... the new one is in the mail! lol )
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OK - figured it out. I replaced the bad starter which, in addition to intermittidantly starting, was cranking slower than it should and drawing more amps from the battery - I suspect causing weaker spark and injection.
I tought about it and realised the problem is the thermowax system - I think it's sticking. This morning, I let my girlfriend take the car to work and had her open the throttle a little before cranking to simulate the thermowax opening - VROOM!
I think the electronic portion of the fast idle is dependant on the mechanical opening of the throttle. Every time the car would start poorly, I could make it instantly go away by revving to 3k. I'm wondering if the system requires the car to rev to 3k before it electronically changes settings like spark and injection mapping to normal?
I'll troubleshoot more when she brings it back later today.
I tought about it and realised the problem is the thermowax system - I think it's sticking. This morning, I let my girlfriend take the car to work and had her open the throttle a little before cranking to simulate the thermowax opening - VROOM!
I think the electronic portion of the fast idle is dependant on the mechanical opening of the throttle. Every time the car would start poorly, I could make it instantly go away by revving to 3k. I'm wondering if the system requires the car to rev to 3k before it electronically changes settings like spark and injection mapping to normal?
I'll troubleshoot more when she brings it back later today.
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