somethings wrong with the fuel system!

[awd laser]

I have a 92 laser rs, and last week while I was driving my bro and sis to school in the morning I noticed that when I stepped on the gas pedal lightly, the car's rpms would drop and it would start to stutter. But when I pressed a bit harder the rpms went up it would be just fine. Except when the rpms were around 2k and lower, and when I stepped on the accelerator just a bit to maintain my speed the car would stutter again. Later on that day around noon while driving in St. Paul, the car all of a sudden started to stutter and died on me! I was going about 35 in 4th gear. I tried to start it up again but right when it started, the engine stuttered and died. Also when this happened, while the key was in the on position, the boost gauge's needle was at -7, then later on it went to 0psi and started jumping around. This made me think it was an electrical problem, also at this time we can hear the fuel pump relay start clicking abnormaly from behind my cd player. A week later while the car was sittin at the house because afer we towed it, I put in a used Fuel pump relay and its doing a little bit better now. But the problem now, is that when I start the car everything is normal, except when I press the gas pedal lightly, the rpms would drop and soon the car would die. Please help me out here! Also the check engine light is on and i do not have a data logger. Thanks for reading hope you guys can help me out here and sorry for the long essay there, just trying to throw out all the info about what happened.

[awd laser]

Also the car is all stock! 14b turbo, 18 years old and never been touched!

[goodhart]

To check your CEL go to VFAQ and click on DSM>Electrical>Retrieving Diagnostic Error Codes 1G. Follow those directions. Also, the stock boost gauges are crap, they don't even read actual boost, so don't even bother looking at that thing.

[awd laser]

do u think it could be a bad fuel pump though?

[goodhart]

It could be, there aren't many CEL's for 1g's so when there is one, it is usually fairly important. Check the code and report back.

[awd laser]

is there a way to find it out without a data logger?

[19TsiAwd90]

sounds like multiple issues maybe, bad maf possibly too, seeings how the stock crap boost gauge uses the maf to "calculate" your boost and you said it was jumping around leading me to maybe think it could be a bad connection or bad maf or possibly even ecu

[Matt D.]

Maybe a bad throttle position sensor. Hard to say without knowing what the check engine light is for.

[awd laser]

we took a look at the ecu and doesnt look like anythings wrong because the one things (sorry forgot the name of it) arent' leaking. But I'll get my video camera and record the car start up and everything so it'll be a lot easier for you guys to understand whats going on.

[goodhart]

is there a way to find it out without a data logger?

To check your CEL go to VFAQ and click on DSM>Electrical>Retrieving Diagnostic Error Codes 1G. Follow those directions. Also, the stock boost gauges are crap, they don't even read actual boost, so don't even bother looking at that thing.


I'll copy paste them for you since you didn't want to follow the directions I laid out:

From VFAQ:

There will be a diagnostic code inside the ECU (Electronic Control Unit) if and only if the 'Check Engine' light on the lower left portion of the dash is illuminated. To get the code that the ECU is reporting follow these steps:

Locate the engine diagnostic test terminal located at the top of the drivers side kick panel (next to the fuse box). See illustration (http://www.vfaq.com/mods/wayback/BradBauer/electrical/terminal.jpg)[/FONT]


You will want to count the pulses that are produced from the MPI terminal. The easiest way I found was to buy a 12v electric buzzer (Radio Shack #273-055 $2.49) and attach its leads to the terminal connector, then just listen for the pulses. You can also use an analog voltmeter and count the pulses displayed.

There are two types of pulses we are looking for "long" and "short". We are looking for a pattern where we have a series of long pulses (1 or more) and a series of short pulses (1 or more), then more long pulses. The codes always start with a long pulse and will finish with a short pulse. So start counting with the first long pulse after a short one. Count until you hear a long pulse after a short one again. NOTE: If you hear a constant "buzz", then your ECU is reporting that there is a problem with the ECU itself, if you hear only short pulses, there is no error code to report (i.e. normal state).
Lets say we write down: S-S-L-L-S-S-S-L-L. We know that we start and stop with a long pulse after a short one. So that happens at two places in our example. At the 2nd/3rd pulse set, and at the 7th/8th pulse set. The pulses between those two are what we want: L-L-S-S-S.
Now that you have the code, we need a code number. For every long pulse count it as a 10, and every short pulse counts as 1. So in our example, it is 10-10-1-1-1. Add them up and that is your code number, in our example 23.
Find your code number below and the resulting diagnostic item.


Self-Diagnosis Codes for 1.8L and 2.0L Engines Code #Diagnostic Item ConstantECU11O2 sensor
12 Volume air flow sensor
13 Intake air temperature sensor
14 Throttle position sensor
15 (1.8L only)Idle speed control motor position sensor
21 Engine coolant temperature sensor
22 Crankshaft position sensor
23 Camshaft position sensor
24 Vehicle speed sensor
25 Barometric pressure sensor
31 (2.0L Only)Knock sensor (turbo only)
36 (1.8L Only)Ignition timing adjustment signal
41 Injector
42 Fuel pump
43 EGR (Ca. only)
44 (2.0L Only)Ignition coil, ignition power transistor unit short pulses only normal state