i just did a FSM test for my car, for 8 kilometers of driving , this is what i found out
after the car warmed up and entered close loop mode it was flasing slowly, on and off with the same interevals but when i get to a stop light at idle the light is always on and the rpms sometimes drop below 500 and jump again to around 600, then sometimes during the drives in the middle of the road it decided to go back to open loop mode again(flashing rapidly), then when i was going down a hill using engine braking, the light was off for about 15 seconds after which i swiched to nutral, and the carr STALLED while i was still doing 60 kmh (~30 mph, i think) so i had to start it , while driving which friked the he!! out of me...
but its not the first time it does that after a prolonged engine brake, then after i started it, it entered closed loop right away and did the same thing at stop lights ocassionally staying on for about 5 seconds and then flashing evenly while in gear(most of the time), then it for some reson decided to stay off for about 10 seconds after which it resumed the regular flashing intereval, (staying on at stop lights while idling), when i reached my home and pulled in the driveway it stalled again for an unknown reason,
now please i hope someone will help me diagnose the problem because the computer doesnt give me anything in diagnostic mode exept the prolonged flash and two quick flashes (code 12) .
PLEASE HELP IF U CAN
oh and another thing when i poped up the hood, the EVAP canister was smelling strongly of gasolin.
(if u haven't read my previous posts the top hose to it is broken and sealed at both ends,)(maybe thats the reason for the smell, and eratic idle)
PLEASE HELP IF U CAN
I LOVE THIS CAR, AND CAN"T SEE IT LIKE THAT
THAT BRINGS TEARS TO MY EYES
(and thats not really good, for people around me seeing me crying by my car)(J/K)
but its really sad
i like third gen cars, and i really want to fix it right
PLEASE HELP IF U CAN
I'LL REALLY APPRICIATE THAT
THANKS IN ADVANCE
AK

 

Please help, it surged really badly the way to school today in first and second gear
PLEASE HELP

 

oh comeon
cant anyone help ??????????????//

 

What type of engine is it?

 

its an 88 mpfi 2.8l v6 with 5 spd. manual.

 

btt!!!!!!!!!!

 

sorry i have t odo this but
BTT again

 

Hi Camaro88.

You have described your problem and I will do my best to help you but I am not a pro mechanic nor am I a senior member on this board but I had my share of problems with both the FI and carb engines.

First of all I tried doing the same thing with the Field Service Mode(FSM)with my car.I wanted to determine if my car was running lean or rich. But as far as I know to get the accurate reading you need to buy a scanner. My car behaved similar to yours. The SES light would indicate closed loop and then it would switch back to open loop waiting at the lights or while going down the hill in neutral. The SES light would stay on for a several second and then it would disappear for 15 seconds.

I have to tell you this: DO not look at this FSM precedure like it is a bible. Get a scanner or make your own ALDL cable and download free diagnostic software and buy a used laptop somewhere and there you go.

Now let look at your symptoms:

- car stalling sometimes
causes: loss or sudden degradation of ignition spark, interaption of fuel flow, sudden excessive fuel flow, or a sudden blockage to the air flow.

- I would replace the fuel filter(assuming you have plenty of fuel in the tank)
- Look for breaks in wires (primary and secondary ignition), check for damage to the insulation of either primary or secondary wires to the ignition coil.
- When was the last time you replaced your spark plugs, cap, rotor,air filters?
- Reset your IAC, check TPS,
- Replace the O2 sensor if it is old. They get worn out and they can not longer read accurately; therefore, sending a false signal to the ECM and possibly commanding the injestors to stay open for a little longer(rich condition).
-Are you getting any codes?

But before you spend $100CND dollars on parts maybe your should ask somebody else for their opinion.

This is what I can suggest to you.

Goodluck Camaro88

PS. At least the weather there is nice not like in Edmonton.



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89Iroc, 305 TPI, WC T5, 3.08 Posi, Flowtech Headers, 3 inch over the axle, Flowmaster 80, Aluminium Driveshaft, Ported Plenum, Air Foil, K&N, AFPR, Smog/AC Delete, 3300lbs, All free mods

 

When the engine is idling for a certain amount of time the ECM will throw it into open loop. That answers one of your questions. I don't know if you are looking at the right things here. When you accelerate, the ECM commands enrichment of the fuel/air mixture. Otherwise you burn a hole in a piston from running so lean. . Hence the constant "on" condition when accelerating. Likewise, when decelerating the engine leans out the mix to, in short, prevent stalling due to low RPM and a whole lotta fuel. Therefore you have a constant off condition. So, given that................We can see you possibly have and overly rich idle condition hinted at by the constant "on" condition. This could definitely cause some of the problems you are having. If the ECM is commanding more fuel at idle you could have a few problems. Vacuum leak or a bad O2 sensor are the first things that come to mind. Also, do all of the things that Daniel recommended. Most of that stuff is just good routine maintenance practice anyway. Plus, the rich condition could have fouled a few plugs making symptoms worse. Start with the basics. Are you getting any codes from the ECM. If so, which ones?? Find out, post back.
bsa


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"If they do not run, Then they will die." - Stonewall Jackson
#3
'87 IROC, 355 TPI, Converted to SD, 700R4, B&M Megashifter, 3.42, Trick Flow Twisted Wedge Heads, Edelbrock Intake, Accel Runners, Comp Cam, Crane Gold rockers, Lucas 24# injectors, Edelbrock headers, Flowmaster 3'' exhaust, Mallory Ignition, Shift Kit, Corvette Servo, 2,000 Stall Torque Converter

1991 RS, 305 TBI, T-5, Bone stock daily driver.

 

thank you for the replies
after my recent rebuild i also changes the cap, rotor ,fuel/air filters PCV valve fuel pump, radiator, a water pump soon,(its leaking badly), so these things are ok.
but i havent changed the plugs/ wires cuz the plugs were new, i didnt think the wires could cause any problems ( do u have any idea to as what they will cost me)
and how do u Reset your IAC, and check TPS,

thanks again
AK

 

oh , and i dont get any codes but code 12

 

In the tech articles there is one that explains how to reset IAC and set TPS. Just follow their directions.

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89Iroc, 305 TPI, WC T5, 3.08 Posi, Flowtech Headers, 3 inch over the axle, Flowmaster 80, Aluminium Driveshaft, Ported Plenum, Air Foil, K&N, AFPR, Smog/AC/Cat Delete, 3300lbs, All free mods

 

what IS IAC and TPS ?

 

i cant find anything about how to do it on my car
can anyone help, i'll try and look for it but its hard opening each post and trying to find things that can be related to reseting the IAC and set TPS, on my car, firstly because i dont even know what they are, or where they are located in my car.
if anyone can help please do ,any advice would be usful.
thnx
AK

 

HI Camaro88.

I do not know if your car has IAC(idle air control). This thing is round and about 15cm long and it is screwed into the throttle body. It has a square connector attached into it and when you pull it out it has four pins inside it.

IAC valve is a stepper motor controlled valve which the ECM moves in order or control the speed on an engine at idle.

Is your engine code "S"? If it is then you have one. The book says that your IAC should be at 600+50 RPM.

If the IAC is not set right your car could have idle problems.

As for TPS(Throttle Position Sensor) it should be screwed into throttle body as well. My TPS is located just above the IAC. So look carefully. This sensor has three wires connected to it. Anytime you open the throttle the TPS voltage goes up smothly. It has to do with smoth acceleration of your car. Any time TPS is above certain voltage your ECM will enter power enrichment mode(rich condition).
The book says that it should be adjusted to:
0.55v

Where can you find the instructions? They are located on the first page when you enter the site. Look gor Technical Articles and you can find it. Just follow the instructions. I do not know how to include a link with replies but maybe if you can not find it give me your email and I will copy those articles for you and send them to you via email.

I do not know what else to tell you. We all want to help you. Just be patient do not give up you will find whatever is causing that problem.

Good Luck.


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89Iroc, 305 TPI, WC T5, 3.08 Posi, Flowtech Headers, 3 inch over the axle, Flowmaster 80, Aluminium Driveshaft, Ported Plenum, Air Foil, K&N, AFPR, Smog/AC/Cat Delete, 3300lbs, All free mods

 

thnx for the reply
my email is 88camaro@www.com (original)
send me the info please if u find it
i'll look for both TPs and IAC right after next class when i'll get home from school
i hope i'll fix this problem
thnx for the replies again
AK

 

ok, i adjusted AIC and TPS, i did a few driving tests and the stallling seems to have gone, woohoo !!!!!
but the surging still there , anything else i might need to check, that may cause the surging???? , and i just filled up yesterday and my gas consumtion was 19L per 100 KM (thats ***** **) i should be getting half as much!!!!!, i'll check next time if the adjustments lowered the consumtion....
but anything else that may cause surging and high fuel consumtion????
PS ( 19 L per 100 km is about 11-12 mpg)(for a 2.8!!!!!)

 

Hi.

So I hear you have got rid of some problems. Good for you.

As for the surging you might have a vacuum leak somewhere. Check for that.

As for your gas mileage there could be few reasons why.

Some of them are:

- small hole in the gas tank
- leaking fuel injectors (can check that by using a Fuel pressure gauge- Your fuel pressure should drop very slowly)
also inspect around injectors where they attach to the fuel rail, all of the fuel line connections at the fuel filter and from the filter to the fuel rail.

One place that ofter leaks is the fuel pressure regulator itself. If the diaphram is punctured then it will leak. Pull the vacuum hose attached at the regulator and if there is fuel in that hose replace the regulator.

Other reasons could be
- A/C compressor not cycling off
- vacuum leaks
- poor engine condition
- high fuel pressure
- restricted exhaust (is your catalyst convertor pluged up?)
- driving habits

That what i got from the book.

Good luck and let me know are you making out.


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89Iroc, 305 TPI, WC T5, 3.08 Posi, Flowtech Headers, 3 inch over the axle, Flowmaster 80, Aluminium Driveshaft, Ported Plenum, Air Foil, K&N, AFPR, Smog/AC/Cat Delete, 3300lbs, All free mods