Lost idle, ran out of options. What to do?
03-04-04, 12:57 PM
#1
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Lost idle, ran out of options. What to do?
Ok, lets start off with the facts.
87 TurboII
13B-RE engine
S5 Turbo
custom FMIC setup.
Microtech LT8.
Now I got the engine and ecu installed sometime lest fall, and it was running beautifully. Had the idle at a rock steady 750 rpms, I could even get it down lower and it would run great. And then it seemed, all of a sudden, that it wouldnt idle. Now the car had 2 year old gas in it, but still ran. Anyhow I changed the filter yesterday. The fusl system is seeing about 40psi, just a about a psi over stock, consildering I have a Walbro. I took my upper intake off the other day because I saw some coolant pooling up, as I didnt have the hose on the nipple on the rear housing tight. I found a few split vaccum caps, and replaced them. I tried adjust ing my fuel settings, my timing, and my idle adjustment screw, but nothing seems to help. I dont know where to go from here.
87 TurboII
13B-RE engine
S5 Turbo
custom FMIC setup.
Microtech LT8.
Now I got the engine and ecu installed sometime lest fall, and it was running beautifully. Had the idle at a rock steady 750 rpms, I could even get it down lower and it would run great. And then it seemed, all of a sudden, that it wouldnt idle. Now the car had 2 year old gas in it, but still ran. Anyhow I changed the filter yesterday. The fusl system is seeing about 40psi, just a about a psi over stock, consildering I have a Walbro. I took my upper intake off the other day because I saw some coolant pooling up, as I didnt have the hose on the nipple on the rear housing tight. I found a few split vaccum caps, and replaced them. I tried adjust ing my fuel settings, my timing, and my idle adjustment screw, but nothing seems to help. I dont know where to go from here.
03-04-04, 02:15 PM
#2
first, i'm guessing you emptied the tank and filled it up with fresh gas. secondly, have you gone through and tried the starter fluid spray around all vacuum areas to make sure you don't have a vacuum leak. thirdly, have you checked the plugs to make sure you are getting good spark.
03-04-04, 04:31 PM
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No I didnt empty the tank. There was very little in there, and I put in about 10 gallons, so I figure what was in there is now very dilluted. I didnt try starting fluid around the vaccum areas though. Also, I havent checked spark, I figured if its running ive got a spark. Maybe its not strong enough?
03-05-04, 01:35 AM
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The key areas to check would be:
All the vacuum hoses; especially the boost sensor. Replace them with silicone hoses (they don't harden/crack under heat and stress). I assume that since you've got an aftermarket computer that you do not have a BACV or an AWS.
Make sure the water temperature and air intake temperature sensors are working properly and are connected.
Also, there may have been quite a bit of water in the old gas; try draining the tank (it's got a drain plug) and filling with fresh gas. Check the fuel pump's flow/pressure as well. Water in the gas can rust/corrode the inside of the pump and make it sluggish or just not work entirely.
The easiest way to check spark is to remove the coil-side of the wire with someone cranking the car. It should easily jump 1/2" from the terminal. Do it with one hand, and don't touch any metal with the other (in case you get zapped). If the electrodes on the spark plugs are round, replace the plugs. And if that picture is recent, I hope those aren't the factory plug wires; if they are, replace them.
Aside from that, replace the 02 sensor (if it hasn't been replaced in the past few years), check for intake/exhaust obstructions, and check all the sensors being utilized by the LT-8.
All the vacuum hoses; especially the boost sensor. Replace them with silicone hoses (they don't harden/crack under heat and stress). I assume that since you've got an aftermarket computer that you do not have a BACV or an AWS.
Make sure the water temperature and air intake temperature sensors are working properly and are connected.
Also, there may have been quite a bit of water in the old gas; try draining the tank (it's got a drain plug) and filling with fresh gas. Check the fuel pump's flow/pressure as well. Water in the gas can rust/corrode the inside of the pump and make it sluggish or just not work entirely.
The easiest way to check spark is to remove the coil-side of the wire with someone cranking the car. It should easily jump 1/2" from the terminal. Do it with one hand, and don't touch any metal with the other (in case you get zapped). If the electrodes on the spark plugs are round, replace the plugs. And if that picture is recent, I hope those aren't the factory plug wires; if they are, replace them.
Aside from that, replace the 02 sensor (if it hasn't been replaced in the past few years), check for intake/exhaust obstructions, and check all the sensors being utilized by the LT-8.
03-07-04, 05:45 PM
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Originally posted by black_sunshine
The key areas to check would be:
All the vacuum hoses; especially the boost sensor. Replace them with silicone hoses (they don't harden/crack under heat and stress). I assume that since you've got an aftermarket computer that you do not have a BACV or an AWS.
The key areas to check would be:
All the vacuum hoses; especially the boost sensor. Replace them with silicone hoses (they don't harden/crack under heat and stress). I assume that since you've got an aftermarket computer that you do not have a BACV or an AWS.
No I dont have a BACV or a AWS. The hose to the boost sensor is new, and the ECU is getting a pretty good reading some im sure the hose is alright.
Make sure the water temperature and air intake temperature sensors are working properly and are connected.
Also, there may have been quite a bit of water in the old gas; try draining the tank (it's got a drain plug) and filling with fresh gas. Check the fuel pump's flow/pressure as well. Water in the gas can rust/corrode the inside of the pump and make it sluggish or just not work entirely.
The easiest way to check spark is to remove the coil-side of the wire with someone cranking the car. It should easily jump 1/2" from the terminal. Do it with one hand, and don't touch any metal with the other (in case you get zapped). If the electrodes on the spark plugs are round, replace the plugs. And if that picture is recent, I hope those aren't the factory plug wires; if they are, replace them.
Aside from that, replace the 02 sensor (if it hasn't been replaced in the past few years), check for intake/exhaust obstructions, and check all the sensors being utilized by the LT-8.
03-10-04, 03:02 PM
#6
the spark problem i was thinking of was that one of your coils wasn't firing. you can run on just leading or just trailing. just trailing will give you all sorts of fits though.
as for the ecu, i'd just load some base maps that are known to work and then figure out what mechanical problem is happening from there.
as for the ecu, i'd just load some base maps that are known to work and then figure out what mechanical problem is happening from there.
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