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Discussion Starter · #1 ·
a while ago my pgm-fi light came on and i would stall out randomly and be unable to start the car for about 10 mins. so eventually i replaced the fuel filter, fuel injectors and spark plugs thinking that might be the problem. well it stoped the stalling but now the light still stays on it rev's higher than it should be. while idleing the rpm sometimes drop and raise as if i was pressing on the gas. at time while shitfing gears all the power will drop and no matter how hard or soft i am on the pedle it wont accelerate. so yea as of right now thats about it. i really hope it doesnt start getting worse and im pretty much stumped. i just cant think of what it wrong with it. oh and every once in a while i have a problem starting it. just have to keep trying the ignition till it finaly goes.
its a 1987 SI. ive had it for about a year and have kept it well maintained not sure how the owners before me treated it. but its definatly seen beter days.
want anymore info just ask
-Thanks
 

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I'm not much of an expert on the older gen stuff but sounds like a vacuum leak of some sort. You should be able to determine yourself if you have one.
 

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Discussion Starter · #3 ·
I'm not much of an expert on the older gen stuff but sounds like a vacuum leak of some sort. You should be able to determine yourself if you have one.
how would i be able to check and or know?. im not really the greatest or most knowledgeable on working on cars, but im willing to learn.
 

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how would i be able to check and or know?. im not really the greatest or most knowledgeable on working on cars, but im willing to learn.
Well you can check all the vacuum hoses yourself, run your hand along each one individually and check for cracks and whatnot. I've heard of people using wd40 or starting fluid and squirt it around the hoses and if there is a leak the rpm's will increase. Another is when your engine is warmed, take the intake piping off and cover the throttle body and again if the engine rpm's increase you have a vacuum leak somewhere.
I hope this helps a bit
 

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THE REVVING up annd down while ideling has happened to a lot of ppls cars i just put a marble in the idle control motor and it stopped bbut i still have a problem every now and then
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PGM-FI light you need to check for error codes left side rear interior garnish take out the ash tray and count the codes flashing on the computer, there should be a list of what the codes mean somewhere that will tell you where to start.

all that other advise is basically useless you have a computer or sensor problem that needs to be fixed first.

the idle hunting / rev bouncing is the fast idle valve on the back of the inlet manifold by the throttle body you need to take the top off it and get a large screwdriver or something and screw the piston inside down towards the bottom that should sort it out. if not you cant have water flow through it so you can check that by pulling the pipes off the bottom of it to make sure.

thats what i would start with.
 

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3gcvc makes a very good point. in addition the hard starting could also be the famous honda main relay issue. im surprised no one mentioned it. ive changed alot of them. if you try to start the car and it doesnt go, then cycle the key 3 times and wait for about 4 seconds then try to start again. this usually gets it going. but the relay will eventualy fail. so see if you can track one down and try swapping it
 

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Discussion Starter · #10 ·
3gcvc makes a very good point. in addition the hard starting could also be the famous honda main relay issue. im surprised no one mentioned it. ive changed alot of them. if you try to start the car and it doesnt go, then cycle the key 3 times and wait for about 4 seconds then try to start again. this usually gets it going. but the relay will eventualy fail. so see if you can track one down and try swapping it
hmmm how would i go about fixing the famous honda main relay issue. casue thats about exactly what i do. and i really dont feel like it failing on me one day...lol. theres a junkyard on the way to my college i think im gonna check it out see if they have any prelude parts. any partsin particular that i should look for?
 

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3gcvc makes a very good point. in addition the hard starting could also be the famous honda main relay issue. im surprised no one mentioned it. ive changed alot of them. if you try to start the car and it doesnt go, then cycle the key 3 times and wait for about 4 seconds then try to start again. this usually gets it going. but the relay will eventualy fail. so see if you can track one down and try swapping it
Damn effin relays. Nothin sucks more than being out with a bunch of people and your car won't start. HAHA
 

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if there is an PGM-FI light when the engine is running its not the main relay so you might want to check the codes still.

the mainrelay should be somewhere in the cabin its on the left side kick panel on the JDM RHD ones not sure about the USDM LHD ones maybe somone else can input, i recomend re-soldering the dry joints in your main relay its just a box it will pull apart and you just get a soldering iron and some solder and redo all the joints and it will never fail again and its better than getting another one from a JY car that might fail eventually anyway.
 

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3gcvc is definately right about getting that check engine light figured out. Like I said before I wasn't familiar with 2g's. On my 88 prelude si, and my crx, all I do is pull back the carpet on the right side floor board and count the blinking LED. In the honda service manual you can find out what it means. I am still convinced that its some sort of vacuum leak somewhere. My 2000 civic had a similar problem and it was throwin all kinds of codes that had to do with the idle air control valve, intake manifold pressure, and a couple others. Good luck and let us know what you come up with.
 

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if there is an PGM-FI light when the engine is running its not the main relay so you might want to check the codes still.

the mainrelay should be somewhere in the cabin its on the left side kick panel on the JDM RHD ones not sure about the USDM LHD ones maybe somone else can input, i recomend re-soldering the dry joints in your main relay its just a box it will pull apart and you just get a soldering iron and some solder and redo all the joints and it will never fail again and its better than getting another one from a JY car that might fail eventually anyway.
IIRC, on the USDM 2g's, it's on the back side of the fuse panel under the dash to the left of the steering column. Don't quote me on it tho. Since mine's a DX I don't have one. I only have the fuel pump relay....
 

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Discussion Starter · #16 ·
ok so in looking at the codes the light blinks 6 times fast. so acording to
0 ECU
1 Oxygen Content
3 Map Sensor
4 Crank Angle Sensor
5 Map Sensor
6 Coolent Temperature
7 Throttle Angle
8 TDC Position
9 No 1 Cylinder Position
10 Intake Air Temperature
63 Intake Air Temperature
12 Exhaust Gas Recirculation System
13 Atmosphere Pressure
14 Electronic Air Control
15 Ignition Output Signal
16 Fuel Injector
17 Vehicle Speed Sensor
20 Electronic Load Detector
21 VTEC Solenoid Valve (1.8L GSR)
22 VTEC Oil Pressure Switch (1.8L GSR)
23 Knock Sensor
30 TCM Signal A
31 TCM Signal B
41 O-2 Sensor Heater
43 Fuel Supply System

6 Coolent Temperature is the problem. is that correct?
 

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ok so in looking at the codes the light blinks 6 times fast. so acording to
0 ECU
1 Oxygen Content
3 Map Sensor
4 Crank Angle Sensor
5 Map Sensor
6 Coolent Temperature
7 Throttle Angle
8 TDC Position
9 No 1 Cylinder Position
10 Intake Air Temperature
63 Intake Air Temperature
12 Exhaust Gas Recirculation System
13 Atmosphere Pressure
14 Electronic Air Control
15 Ignition Output Signal
16 Fuel Injector
17 Vehicle Speed Sensor
20 Electronic Load Detector
21 VTEC Solenoid Valve (1.8L GSR)
22 VTEC Oil Pressure Switch (1.8L GSR)
23 Knock Sensor
30 TCM Signal A
31 TCM Signal B
41 O-2 Sensor Heater
43 Fuel Supply System

6 Coolent Temperature is the problem. is that correct?
That would appear so. I have this code go off periodically in my crx and doesn't seem to affect anything. I'll read through my manual see what I can figure out for you on how to troubleshoot it.
 

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I found this much and you should be able to determine whether your sense is bad or not. Here is an online site that seems to be somewhat useful (http://geocities.com/chipman_13/sensor-trbl-shoot.html#TA). Im still trying to figure out what's wrong with my civic. Reset the codes today and it was throwin vss, idle air control, and a low voltage input for the TPS. I'm pretty sure its some wiring/vacuum issues.

Code 6 - Coolant Temperature Sensor (ECT)
Helps determine the Pulse Width of the injectors at start-up. When this sensor starts acting-up, the engine will get hard to start, on "warm/hot starts". The wax pellet inside the sensor has gotton lazy. Sending bogus signals to the ECU, causing it to flood the engine.
When cold, it should read 2.5-4.5 volts. Also, check the IAT sensor for the same voltage, they should read close to the same. When full warmed should read .5-.6 volts. You can use a resistor with a 330 ohm 1/2 watt spec, or one from Radio Shack part# 271-1113. Start the engine and let it warm up, then kill the engine. Put the resistor in the wire connector on the harness. Start the engine, if problem goes away then replace the sensor. Use this only for temporay testing, it will cause other performance issues. Meaning the ECU will think the engine is always warmed up, when it's not.
This sensor is also known to cause hot and cold starting problems.
When the engine is hot, the sensor is telling the ECU that the engine is cold. Flooding occurs, due too a improper injector pulse width. Unplug the sensor if you need to start the car in a hurry. The ECU will throw a code and go into limp mode, however you will be able to drive it.
 
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