Rookie mistake, did i fry my ecu?
07-09-06, 12:57 PM
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Rookie mistake, did i fry my ecu?
i think my ecu might be gone - i messed up and connected my battery backwards momentarily, now the car cranks but wont start. i have an rtek 1.7 chipped ecu that i have been waiting to install, but i dont have the 720cc injectors. i want to swap the chipped for the stock ecu just to see if the car will idle - if i do so without installing the injectors, will the car run at idle?
07-09-06, 01:07 PM
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did, they are all still ok - checked egi fuse etc... in the n gine bay, and all the ones inside. since the egi fuse didnt blow, does that mean the the backwards current could have fried the diodes and crap in the ecu? is this a good next step - to swap ecu's?
07-09-06, 01:25 PM
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Tell me the symptoms other than the engine won't start.
Does the fuel pump run right now if you jumper the yellow fuel pump check connector in the engine bay with the key to ON????? LIsten at the tank filler for the sound of the pump.
If the pump works,then that means the ENGINE fuse in the interior is still good and the Main Relay should be pulling in along with the Circuit Opening Relay. Which is good.
If you mean that you go to START and hear nothing, no starter aciton much less a click, then try this: Key OFF. Then turn the headlights on then off. IF they went up/down but you have no starter action, then look for the IGNITION SWITCH power wire being burnt in two. It's a pure black, single connector wire located about six inches inboard and below the engine fuse box. Write back.
The RTEK should be ok since you only use the primarys for starting and non load. But I assume the primarys are stock 550.
Does the fuel pump run right now if you jumper the yellow fuel pump check connector in the engine bay with the key to ON????? LIsten at the tank filler for the sound of the pump.
If the pump works,then that means the ENGINE fuse in the interior is still good and the Main Relay should be pulling in along with the Circuit Opening Relay. Which is good.
If you mean that you go to START and hear nothing, no starter aciton much less a click, then try this: Key OFF. Then turn the headlights on then off. IF they went up/down but you have no starter action, then look for the IGNITION SWITCH power wire being burnt in two. It's a pure black, single connector wire located about six inches inboard and below the engine fuse box. Write back.
The RTEK should be ok since you only use the primarys for starting and non load. But I assume the primarys are stock 550.
07-09-06, 02:26 PM
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yes 550 primaries. i have a fuel cut switch under my dash that interrupts the fuel pump. and that switch was off - so that should have saved the fuel pump. i will check for fuel pump activity though. you say i should jumper a yellow connector in the engine bay?
07-10-06, 01:44 PM
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Originally Posted by gxlbiscuit
umm if you connect your battery backwards you will blow your main fuse.......
hmmmmmmmmmmm.....he says the engine turns over when trying to start the car. How does that happen with a blown Main Fuse?
hmmmmmmmmm......it also disproves my idea of no power to the ignition switch. Oh well.
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07-10-06, 01:54 PM
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ok... so now i have swapped to rtek chipped ecu, still no-go... my plugs are wet (with oil?) when i pulled the plugs they all are sparking on the block - so everything seems ok with the ignition/spark side.
i pulled the fuel return line and got about a tablespoon of gas which i poured into the intake manifold... cranked it... still no hiccup even with a little added fuel.
are there any fusible links in the 87 chassis?
im test lighting my way around now looking for power everywhere. hope i find something broken soon so i can get somewhere
ps. hailers - where is the fuel pump test plug located? i can't find any yellow plugs under the bonnet. do you mean for me to pull the fuel pump relay and put twelve volts in the top right?
i pulled the fuel return line and got about a tablespoon of gas which i poured into the intake manifold... cranked it... still no hiccup even with a little added fuel.
are there any fusible links in the 87 chassis?
im test lighting my way around now looking for power everywhere. hope i find something broken soon so i can get somewhere
ps. hailers - where is the fuel pump test plug located? i can't find any yellow plugs under the bonnet. do you mean for me to pull the fuel pump relay and put twelve volts in the top right?
Last edited by oblio; 07-10-06 at 01:58 PM.
07-10-06, 02:07 PM
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if you are getting spark and it still didn't even try to fire up when you added gas to the manifold then i would guess it is severely flooded. try the unflooding procedures, the Rtek 1.7 should have clear flood built incutting the fuel pump at full throttle.
07-10-06, 02:13 PM
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i have a fuel cut switch installed under my dash - i can kill the pump manually - but aside from that, i cranked the motor when i had all four plugs out and nothing really came out... the egi comp fuse (by the drivers side strut tower) is showing a little backfeed. the test light glows like 12v on the left side, but also has a faint power source on the right side (bulb glows a little) the fan also turns on when i pull that fuse...
07-10-06, 02:15 PM
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The fuel pump check connector is yellow in color and has two sockets. It is located near the afm/boost sensor/right front strut tower area. It is not tied down and just floats around on the harness. It might have a black piece of shrink tubing covering it.
You jumper the two sockets on that yellow plug. Turn the key to ON. Then listen for the pump to be running, either at the tank filler.
Your car does sound flooded though. I'd buy a can of starter fluid and spray it into the air filter for one to two seconds only then try to start. It might help but a severly flooded car might not respond.
If you have spark that usually means the fuel pump is also working because the fuse *engine fuse* in the interior is the same one that pulls in the Main Relay and the Circuit Opening Relay, so it does NOT sound like a blown fuse in any way.
You jumper the two sockets on that yellow plug. Turn the key to ON. Then listen for the pump to be running, either at the tank filler.
Your car does sound flooded though. I'd buy a can of starter fluid and spray it into the air filter for one to two seconds only then try to start. It might help but a severly flooded car might not respond.
If you have spark that usually means the fuel pump is also working because the fuse *engine fuse* in the interior is the same one that pulls in the Main Relay and the Circuit Opening Relay, so it does NOT sound like a blown fuse in any way.
07-10-06, 03:37 PM
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well... crap - i jumpered the connector, and no fuel pump buzz. tried to dump a half cup of fuel into the throttle body and nothing. i also pulled all the plugs and left them connected to the high tension leads - they all fire with strong spark - and appear to be timed correctly as well. what could be wrong???
07-10-06, 06:22 PM
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Yes! got the motor started (used de-flood procedures) and it idled smoothly but smokily. i let it warm up... stopped it, switched from rtek chipped ecu to stock ecu, started it again. smooth idle. went to get gas and drive it around a little, stopped the motor and started it again... then about 3 miles away it died while idling when i was coasting down a hill. i roll started it, let it idle, it died again. started it on the roll again, left it in 3rd gear, and got some of the LOUDEST backfires i have ever heard. then it croaked. is this common after a floodout? this is the first time in 2 years that the car has ever given me problems starting. the motor has about 31k on a rebuild.
07-10-06, 10:41 PM
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ok. i think i know what happened. when i added 2-stroke oil to get the compression back up after my flood event - i poured it in just under the intercooler, before the throttle body. by the end - i had added about 20 oz of 2-stroke, which all pooled in the intake plenum. if i clean the plugs, the car will start and idle, but when i rev it, it dies. i think that oil that is left in the manifold is fouling my plugs and causing the erratic idle and eventual death of the motor. also - my spark plugs are like 30,000 mi old, the t2 plug was pretty well deteriorated... thanks everybody for your helpful posts 
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