I have a 86 Fiero GT w/a 95 riv 3800SC motor. The car will start and then immediatly die out. There are no codes present. I have replaced the fuel pump (don't know why), am getting 40psi at the rail w/key on. Replaced the camshaft sensor, magnet was present on gear, crankshaft sensor. Checked the injector harness for pulse w/idiot light. With key on and light grounded I get solid light on red wire. Then w/light on positive and engine turning over I get pulse on green wire, but as soon as the car starts, the pulse stops, the engine dies and I get one more pulse at the end. Not sure if this is normal. I tried pulling all injector wires off and tested each one then replace on injector but no difference. Any ideas would be helpfull. Also I can manually feed fuel in at the air intake and keep the car running.

Are you 100% sure that the VATS was disabled when the PCM was programmed? If the VATS wasn't disabled it will cut fuel a few seconds after the engine is started and it will die abruptly.

Edit: 1995 would make it a S1 3800, was vats present in obd1 programming? If it is then it may be cutting your fuel which would explain why you're able to keep it running by spraying some in the intake.

------------------

[This message has been edited by JamesCurtis (edited 08-26-2009).]

I'm just guessing here but it could be your throttle position sensor is bad.

------------------

Click here for all your Fiberglass part needs

Yes ,the VATS was on the 95, not sure if it was disabled in the pcm, but the car was running and driving daily for about 3 years and then was left in the garage over the winter and this is where I am now. Would it even be possible for that system to enable itself. The swap was done at a fiero place in Colorado quite some time ago and I am not even sure if the pcm was reprogrammed or not. I was thinking of getting a new one, but now am not sure if a stock one would work.

As far as the TPS, I can hear it adjusting when the key is turned on and off so I believe it is working. I also tried unplugging and starting but with no avail.

The 2 places I would look would be under the rear center console where the PCM is located and under the driver's side dash. Just a guess.

Found my pass key bypass module in the center console w/the companies name American Custom Engineering out of Durango, CO. and their phone number on it but they are out of buisness. So...does anyone know how to test this type of module, or what to do to make it work, it has three wires coming out of it and is probably some kind of resistor, but is sealed in some type of silicone or something. Not a factory look at all. LOL. Please help, I feel like I am getting close to driving again.

http://home.hiwaay.net/~davida1/passkey.htm

I can make ya one if you can't bro

Do you know if I can test the one that I have to see if it works. I am not very good w/electronics but could probably find an ohm meter and test the module if I knew what values it should be putting off. According to the article you sent me, I seems it should be 50hz. Can I test for this w/a multi meter.

No, you can't unfortunately

Take it to an electronics shop with an oscilloscope

OK. My brother is ordering a new bypass module from a fiero site he said he saw. I will let you know what happens. In the mean time I was rechecking everything and was a little concerned about the fuel pressure. It is a new pump and is putting out 40psi w/key on at the rail. Is this enough to run the car? If the pressure drops, wouldn't the car still at least idle? I am just trying to rule out anything else that might be causing this problem. Plus, writing it down helps me think of what I have done already.

Dude, you can make that bypass for like 5 dollars

Ahrrrg. I know but I suck at electrical stuff and w/no way of testing it, how would I know I did it right.

Today I found the company that did the engine swap in my car. They are now a towing company in another town but he said the guy that did my car is still there and would have him call me tomorrow. I don't know what good this will do, but hey, any help I can get, I'll take, ya know.

I said I would make ya one lol

Only would have taken a few minutes, coulda paid for parts and shipping and I'd woulda been good

Thanks. I wasn't trying to dis ya or nothin. Just trying to get things done. Turns out he hasn't ordered it yet so if you could build me one, It would be greatly appreciated. Let me know how you would like me to handle payment. Is there a private chat on this site?

Bump?

Proper PCM programming maybe?

Better than a module by far.

http://www.fastfieros.com/obdii_programming.htm

The motor is a 95

That isn't obd2 Loyde

Your module went out today at noon

Darn

Keep me straight Dallas... I actually can program OBDI also. I have had my little pocket programmer about 10 years now.

http://www.fastfieros.com only OBDII today however.

[This message has been edited by FastFieros (edited 09-04-2009).]

Thanks Dallas, I will let you guys know what happens.

Pink - 12v

Black/white - Ground

Blue - Signal



I didn't wanna use one of my cases on a free one so I made it out of two halfs of a RAM package taped up lol

Those Baker Electronics VATS signal generators work but you must carefully determine which signal frequency your PCM is looking for on the VATS input. Different year PCM's look for different frequency levels. I know a guy Auburn NY who has a beautiful Fiero who just completed his 3800SC swap and we correspond reguarly. He ended up ordering two VATs generators before his engine would start up.
While the VATS signal generator will work, I don't prefer this method as it adds just another component that could fail. As Loyde has indicated removing the VATs function in the programming is the best way. His PCMs have it and I learned the technique on disabling the VATS from him. It requires about 4 steps and its not a simple "shut the switch off" solution.

------------------
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, 3.4" Pulley, N* TB, LS1 MAF, Flotech Exhaust Autolite 104's Custom CAI 4T65eHD w. custom axles, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

quote Originally posted by Dennis LaGrua: Those Baker Electronics VATS signal generators work but you must carefully determine which signal frequency your PCM is looking for on the VATS input. Different year PCM's look for different frequency levels. I know a guy Auburn NY who has a beautiful Fiero who just completed his 3800SC swap and we correspond reguarly. He ended up ordering two VATs generators before his engine would start up.

Ya, you're wrong.

Passkey II is Passkey II

Now if it's a previous VATS system, then yes, it is different

[This message has been edited by RideZiLightning (edited 09-05-2009).]

Well, like I said. If this works I will probably send the pcm out for a reprogram later. Right now I just want the cheapest fastest fix possible so I can drive it again before winter. I have two many projects going. Anybody looking for a 75 Grand prix, LOL. Also been tuning a 95 Eagle Talon tsi AWD. What a fun car that is. My 12 year old thinks he is getting that one when he's old enough to drive. Double LOL. He'll end up in jail just like his dad did when he was a kid. Anyway, Looking forward to getting that module. Maybe Tuesday.

quote Originally posted by RideZiLightning: Ya, you're wrong. Passkey II is Passkey II Now if it's a previous VATS system, then yes, it is different

Up to 93 is a 30 Hz, 94-95 is a 50 Hz There is a difference in the operating frequency, but both are still Passkey II

quote Originally posted by josef644: Up to 93 is a 30 Hz, 94-95 is a 50 Hz There is a difference in the operating frequency, but both are still Passkey II

Passkey 1 uses a 30hz frequency

take the signal wire from the pcm and tap it to ground like a nervous twitch as you try to start the car.. if it continues to try to run or starts the module is pretty well the problem.. I had to do that to my car a time or two... not explanation as to why it works but it does.. some times it too a few tries but it always started the car and would not have to do it again unless i disconnected the battery..

------------------


87 GT
series 1 3800sc (7.597 @88.53 1.579 60ft)
86 SE
sbc / 5sp

quote Originally posted by superCfiero: Well, like I said. If this works I will probably send the pcm out for a reprogram later. Right now I just want the cheapest fastest fix possible so I can drive it again before winter.

I would have the VATS disabled in the PCM. I always use Ryan at www.gmtuners.com. He's in Fort Wayne, IN so your turn-around time should be pretty quick... That eliminates the module and gives you one less point of failure. I've had great support from him on the phone and email...


------------------
-Brian

My 87 GT Poly Suspension Upgrade (all pics) thread https://www.fiero.nl/forum/Forum2/HTML/094633.html

[This message has been edited by MulletproofMonk (edited 09-08-2009).]

You get it bro?

I had to learn how the ignition module works to do my standalone ECU.
If the engine fires at all it is probably not a fuel or sensor problem.
Either the passkey stuff they were talking about or it could be the "bypass" wire on the ignition module. The Buick C3I ignition module controls ignition timing during cranking automatically without any PCM input. The engine will crank and fire a few times then die if the PCM is not sending a "bypass" signal to the ignition module to enable spark control. You would think it would set a code but if it's not the passkey it's worth a check..

Ahhhh, got the new module and going to the garage to try it. I'll let yall know.

Heck ya!

You're welcome

ok. checked all the plugs they were good but no spark off the NO 2 coil, but NO5 is ok. Wouldn't they both go out if it were a bad coil? Well I think I have another in storage somewhere, I will have to dig it out. If anybody else has an idea, let me know.

Update!
It is so fast its sick. After all the crap that I went thru w/this car it was well worth it. I got a new set of GM injectors off ebay and put them in last night. Wow. Turned out 2 injectors were completely dead and one was firing inter..intermit....once in a while. (Haha).
Car runs great and is much faster than my turbo talon. I took off in first gear and reached redline so fast I couldn't get the clutch in before the cutoff killed the engine. (Can that be disabled, it felt like it had a lot more to give?)
Thanks everyone for your help.
All thats left to do are the front brakes and I am getting a clacking noise out of the back, might be a bad cv joint, not sure, hope its nothing serious.

Well, I dont know where your rev limiter is, but anything past about 5100rpms is pretty pointless in a SC3800.

Rev limiters can be removed, and SHOULD BE in manual setups, because hitting them is quite bad for your motor.

Well, as far as after 5100being pointless, I don't know about that. What I do know is I put the pedal to the floor in first gear and listened for the engine rpm to wind out when all of a sudden the engine cut out, I looked down and the tack was past 6000 and dropping. The engine felt as tho it had a lot more to give before cutting out. but, of course, what do I know, I was only driving the car, you are the expert. Again, thanks for the help. And thanks to ridezlightning for the module.