My MR2 is off the road, and has been since July, with water related gremlins.
Itll work fine for months on end in dry weather (such as last summer) but if you introduce road-spray or rain it has a whole world of problems.Ive attempted to describe these on here before and not had much luck with solutions.
Since I was last on here Ive collected a lot more failures and tried a lot more repairs. This seemed like a good time to come back, wave, say hello to a few people and then scream HELP!!!The historyThe car will be fine one minute then bog down and simply switch off.
There's no often warning and there doesn't seem to be any 'restart' criteria. Sometimes it'll go, others it won't. There's never a need to reset the immobiliser so I've discounted that. Sometimes attempts to restart are accompanied by a huge arc from the ignition coil, other times there's serious backfiring/dieselling.The fault seems to occur most when running with the engine under load, but not always.
Sometimes you can dip the clutch and it'll seem to work fine until you load it up, sometimes dipping the clutch won't help. Sometimes it'll hold together - spluttering and dying for almost half a mile. Normally it just dies. On one occasion I saw a massive spark, apparently from the coil to the body.
On other occasions it seems to have a weak, sporadic spark at the plugs. Sometimes it'll engage in a spot of light dieselling when it restarts, sometimes it won't bother. Sometimes it'll misfire like mad when it restarts, other times it fires like nothing happened. Sometimes it'll refuse to start for no apparent reason the morning after these episodes, sometimes it's fine. There seems to be no link to the weather the morning after (i.e. sometimes it will restart in the rain next day, sometimes it wont restart in dry weather next day). One time it failed to restart for four weeks. Sometimes it'll fail to start after being sat still during a rainy night.
It will almost ALWAYS cut out or misfire badly when I drive through standing water on the left side of the road - i.e. passenger wheels (n.b. due to UK driving regulations it's tricky to test what happens if I drive through standing water on the right hand side - i.e. drivers wheels).Sometimes, even in heavy rain, it's fine unless you use the last inch of the throttle, then it bogs down, but it's fine on full boost, maximum attack through the gears at
"full pedal travel minus one inch". The lights/stereo etc seem unaffected until the revs really die, then the lights dim as you'd expect.
It cuts out with the headlights lights on or off. There are never any ECU codes. I recently had it in the garage for 10 weeks
(so it should have been thoroughly dry) when I was forced to leave it outside over-night. It rained overnight and the car wouldnt start next day for hours. Taken together with the fact itll stall if I drive it through standing water when it isnt raining you can see that water coming from top or bottom will kill it just as quickly.It's getting really stupid now.
I spent both days last weekend on it and it's now misfiring in a light mist of rain (even though I'd been running it before the rain started and it was fine). There simply wasn't enough rain coming down to get the loom/engine parts wet but it was STILL misfiring.Things Ive tested or changedCoil
- replaced with new & supply voltage verified. Spark plugs
- replaced with new, recommended standard grade, platinum, gaps set to 0.8mm IIRC (standard basically). All plugs removed and visibly inspected for good sparks.Igniter
- replaced with known good unit. Air Flow Meter
- (Inc air temp sensor) replaced with known good unit.Air filter
- replaced with Apexi. Throttle Position Sensor
- replaced with known good unit, both units electrically within spec. All temp sensors
- replaced with new (all new and old units electrically within spec). Dizzy cap
- replaced with new inc all seals (oil and water) twice, for good measure, both units electrically within spec. No evidence of previous water ingress.Rotor arm
- replaced with new (twice, for good measure), both units electrically within spec. HT leads
- replaced with new (twice, for good measure), both sets electrically within spec. Distributor
- cleaned and electrically checked as per manual for resistance and continuity (note unable to check air gaps as special service tool required). Fuel filter
- replaced with new. ECU
- replaced with known-good unit. Cold start injector
cleaned & electrically tested.Main injectors, cleaned and continuity/resistance tested.
Lamda
- checked fuelling on RR. Rich, but basically OK. To be electrically checked as per workshop manual at earliest opportunity, but the known functions of the lamda would not allow it to cause this failure - (ref TBD forum).Fuses
- all removed, checked and cleaned. Fuse boxes
- disassembled, cleaned and tested. Relays
- all removed, checked and cleaned (then cycled 20x rapidly on and off with the key as recommended for certain failures - MANY times). Also exchanged all relays with units from another forum members car while mine was failing to start. No change - still wouldn't go and his never failed to start with my relays in there. Thermostat
& coolant - replaced.Alternator
- nearly new when I bought the car but cleaned and tested anyway. Battery
- replaced with new & terminal clamps checked. "Noise surpressor" - replaced with unit from scrapped car - no change.Injector solenoid resistor packs
- checked OK.Boost pressure sensor
- resistance tests pass ok. Live tests still need to be done. This is one of the high suspects at present.Air hoses
- removed, inspected, replaced. Some new clamps, some old. All leak tested via fairy liquid/bubbles approach. Dump valve
& ancilliary hoses/valves - checked for leaks. Engine looms
- stripped back to individual wires, removed from cable routes/sleeves, inspected, water-sealed with spray repellant, re-wrapped, re-secured. Checked for chafing against corners, moved wires around to ensure any unseen worn patches are no longer together. Continuity tested as per circuit diagrams/schematics from workshop manual. One broken wire repaired (no obvious difference before/after).All earth points/straps
- removed, cleaned, checked (even on the bonnet side panels!!!). All main power connections to engine
(e.g. starter motor) checked and cleaned.All electrical components
- plastic wrapped to shield from water ingress (made no difference so removed these due to fire risk). Injectors
- connectors removed, cleaned, sealed. Timing
- base timing reset and verified. ECU-adaptive timing disabled while car stalled by bridging diagnositcs port, no effect.
Alarm/immobiliser: cables also checked for water ingress and sealed as per engine-bay wiring.
All back-wall components
- remounted on longer bolts and shimmed to avoid water running off the bootlid from swamping them.Other issuesPost-charge starting:
My car has been off the road for a long time now with its' water-related gremlins, this means that the
(brand new) battery will periodically go flat. This tends to happen every 5 weeks or so.Every time I take the battery off charge and reconnect it to the car the same thing happens.
Turn the ignition to the second setting, the dash/door lights all come on as they're supposed to and the stereo powers up.
As soon as I try to start the car there's a large CLICK and everything dies. It'll stay dead for up to half an hour then suddenly decide to restart.This is quite distinct from the wet-weather problem as 1) the car has been in a dry garage for weeks before every occasion and 2) everything dies.
In wet-weather incidents its only the engine that fails, everything else still works.I'm a bit baffled.
I haven't looked at the circuit diagrams yet but I won't have time for a week or so - if anyone has any ideas I'd be happy to hear from you.Black liquid from exhausts:
If I start it up in the garage and leave it sat still it'll spit little drops of black liquid out of the exhausts.
After just a couple of minutes there are stains on the floor where these have landed and dried out. Quite a few cars do this a bit, but if I hold my hand over the exhaust and rev it, this happens:
I used to think it was overfuelling but I've leaned it off as far as I dare and it's made no difference.
Any ideas?
Thanks for reading!
