I am new to this forum, but i need some help getting this project started. I swapped a series III 3800 SC into my 88gt. Everything is in place and all the wiring plugged in but it wont start. The engine does crank but right now i am getting no spark and no fuel injection. There is fuel pressure in the fuel rail, but the injectors are apparently not spraying. I know it sounds like a computer problem, that is what i also thought at first becuase the check engine light did not light up when i put the car in the start position, but i printed out the wiring schematics for the computer and checked the wire that brings it electricity and all the grounds going to the computer, they all checked out. The fuel pump runs when i first turn the electrical on, but it does not do that when the computer was disconnected. Also, when i connected a cheap scan tool to the computer it did not read any codes. The tach does read rpm s when the engine is cranking.

I know it is a lot, but does anyone have any ideas or can point me in the right direction?

I rewired mine about 3 times and everytime the thing wasn't getting spark. Then i grounded the metal attached to the coil pack. "the part bolts to the block" thats attached to the pack itself, and i got spark from there on out.

I dont have a series 3, i did a 92 swap. But on all of your injectors there is a hot wire when your turn it on. Check them all and make sure power is getting to each injector And hope you have the other wires going where they need to go lol. Aside from the grounds coming off the injectors that plug into the pcm there were two wires coming out of the pcm that were labeled injector grounds. Ground them if you got em.

If your fuel pump keeps shutting off. You could temporarily ghetto rig it to a switch or an ignition wire? just to get things going.

I dont know if you have it but i had to deal with a bunch of pass key bs. I had to get a bypass thingy.

Im not an expert but the same stuff happened to me so just give it a look! Im sure people who know what their doing will chime in soon!
Good luck!

Good Morning
Here is the deal on the 3800SC series lll. First I'm in the process of doing the same thing, And the samething is happening. The problem is the VATS vehicle anti theft system, PCM the computer and the BCM body control module. You did'nt say what year the motor is. All motors up to and including 2004 can be reprogram and the person to talk to is Lodye@ FastFiero. Lodye is on the list and will probably jump in. He's is in the process of redoing mine. I have a 2006 and he going to replace the 06 PCM and the BCM with one from a 04. But until you get by the VATS I don't think it's going to run

My fuel pump is fine and its getting fuel pressure all the way up to the fuel rail. And i also checked the pink wire going to every injector, the wire is hot as it should be. When i connected a voltometer to each injector plug on the wiring harness side it read about 6 volts, when i cranked the car with the voltometer still connected the reading dropped to about 3.8-4 volts. I am going to purchase a set of test lights so i can more accurately test it, but until then thats wut i did. So chris, i should ground the coil pack? i assumed it was already grounded becuase it is connected to the block? i ll give it a try. I am also not sure about the whole passkey thing, Loyde is the one that made my wiring harness and programed the pcm, the engine is a 2004. Does his wiring harness already bypass the whole passkey thing or do i need to take care of that seperately? I am not very familiar with the VATS or the BCM. The PCM i have was out of a 98 bonneville and loyde is the one that programmed it for me. Another concern that i have but am not too sure about is the deletion of the supercharger bypass solenoid and that entire mechanism. With no supercharger bypass am i going to be blowin head gaskets like crazy or is it safe? Becuase i will be planning to run a smaller pulley in the future once the car is up and running.

[This message has been edited by minathomas3 (edited 05-01-2007).]

Ok, Let me give everyone some history about Mina…. First, he is not the DIY type person that should be working on his Fiero for the VERY first time with a 3800SC installed to it. He has very limited understanding of electronics, and proper approaches to troubleshooting.

I built Mina’s wiring in about March 2006. It has taken him this long to get at this point of trying to start the car.

First, he had the wiring improperly installed at the starter. He takes the nut off the solenoid side of the ARMATURE and attaches the battery cable. Then he GROUNDs the other terminal until he emails me pictures and I see what he has done… well he removes the ground, and not the positive, so now it turn over all the time when he attaches the positive and negative to the battery. Finally after about 2 weeks he understands this and trys again. I now solved this problem in all harness after I saw he was able to mess that up.
Now he sends me some picture with the battery sitting the strut tower and the negative just running to the engine, and the positive just clamped to the starter post. The engine will turn over, but not start.

He wants to attack my wiring, my PCM, and about everything else except his skills and attempt at getting an engine to a Fiero that he as zero clue how to do.

He may have shorted the PCM by now.

He most likely has enough voltage to turn over the engine, but will not maintain 10.9 volts when cranking so the PCM will stay turned on.

NO Mina, again, the ICM / Crank sensor / Cam sensor harness is not part of my wiring, and it has its own GROUND that you must connect. It is the ONLY ground for that ICM / coil pack assembly. I told you about this one on the phone about 5 months ago.

I will tell you again Mina… GET a new battery, and wire the connections correctly.

I have sent about 20 emails with this guy trying to help him, I have spent many times in phone calls trying to help him… He admitted this is his FIRST attempt at automotive skills, and I am tried of trying to educate him on a simple battery hookup…

It is a S3 engine, but it is converted to S2 at the TB, wiring, and PCM... so, treat this as a simple S2 installation guys.

Loyde

i am not attacking and never was attacking ur workmanship loyde and i dont understand why u insist that i am. I am just trying to get my car started. He is right, i am not as educated in the subject as some of u might me, but i am looking for some help, and since u dont want to help me i came here for help.

Didnt have time to read, but here is the skinny.

The ICM (ignition module) is the heart of it all. As long as the ICM has power and a crank signal it will spark. The ECM uses the ICM for fuel timing, so without a functioning ICM, the ECM will not fire the injectors. VATS connects to the ECM and only disables fuel, and often it will give fuel for 2 seconds then shut off.

SO If you dont have spark, you have a problem with the ignition system. Either the ICM does not have power/ground, or its not seeing crank sensor signal. You can test the +/- easy enough, and the wires to the crank sensor should show a low AC (yes AC not DC) voltage when cranking. Thats not a definitive test, but showing nothing at all is a good sign its bad.

Mina.... its a 12volt system..... if you have 6 volts anywhere... PROBLEM... if you have 11.0 at key on, no crank, and it falls 4 volts during cranking, you have a bad battery, or your cables from the battery to the engine/starter are wrong.

The engine will crank all day with 10.0 volts, but the PCM and ICM are not going to work correctly without 10.9 volts.... This problem has come up many many times on PFF and no one spots the issue... A simply new battery, and properly run cables goes a long way to troubleshooting what is wrong correctly.



Mina, I have been trying to help you since 4-06 to get this started and running. We have exchanged 22 emails, and I cannt even count the amount of phone calls... get the battery mounted and the cables run correctly.

Loyde

minathomas3,

Maybe you should send the ECM to Loyde for him to see if it is fryed. Im sure he could tell right away.

Are you sure you have the crank position sensor and the cam position sensor hooked up correctly?

The white w/black stripe is 12v ( I think key on) and the black w/white stripe is ground on both sensors.

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

" DRIVE IT LIKE YOU LOVE IT"

thank you everyone for the help, i will test the both sensors to make sure that they are getting electricity. I actually have a battery in the car right now and it is hooked up with actual cables not the clips that u see in the picture, yes those clips were a problem becuase when i was using them the engine would only crank for a second then stop. I will test everything u guys have talked about and get back to you, not sure when i will test them becuase i have finals next week but i will test them as soon as i get a second. And i will also charge the battery as i have done in the past to make sure that the battery is not the problem. But when i disconnected the computer from the harness and tested the power wire at the harness it read 12. something volts, this was when the engine was not cranking though. So i think the pcm should hopefully be getting atleast the 10.9 volts it needs when the engine cranks. I hope the problem is just an icm ground or something and an easy fix.

Try to use a different battery, not just charge the old one... My father and I had the same problem with a Camaro. We swapped a LS1 engine into it, and the voltage readings were all good, the motor would spin forever, but never started. We were totally in the dark about it! Then we swapped batteries and it fired up the first try!
Good Luck with your car!

P.S. A 3800SC swap on your first try??? You got some balls!!! (or just a big wallet!)

well, my wallet is kinda really thin, so i guess that leaves me with balls.

But anyway, i tested the +/- wires going to the crank position sensor, they are both fine. I also removed the plug that plugs into the icm to test the + wire there, the pink one. I also tested it during cranking to see how much the voltage dropped to and it did drop to 10.5-10.6 volts. Which is under 10.9, so i bought a new battery, which is 850cca, more than enough since the grand prix gtp uses a 695 cca battery. I tested the same thing while cranking and the voltage still dropped to 10.6 while the car was cranking. I know it is probably a bad ground but does anyone have any idea where i should start looking for this bad ground or if it could be anything else.

Right now, just to keep the voltage above 10.9 during cranking i have 2 batteries rigged together, this keeps the voltage at about 11.0 volts when im cranking the car. I am still not getting spark though. I think my Crank Position Sensor is bad becuase i notices today that when i crank the car the rpm gauge jumps to maybe like 200rpm then just rests at 0 the entire time, is that evidence of a bad crank sensor?

Another issue that i am having is that my fuel pressure is disgustingly low, it remains at 25psi while cranking. I thought the fuel pressure regulator might have been bad, so i changed that, but i still get the same exact 25psi reading during cranking. Anyone know y that might be?

Obviously its not the fault of the battery, more like the fault of the grounds/power wires being the wrong size....

ok, i have the problem narrowed down to either a fried pcm, which i doubt, a defective icm, or a bad crank shaft position sensor right now. I am going to try to get a hold of an oscilliscope to test the crakshaft sensor. Does anyone know if there are any places that rent them out? If not, will a cheaper oscillsicope do the job? wuts the deal with the frequency or band width of an oscilliscope and how many channels it is. wut mhz and channels would be adequate to test my sensor and wut difference do these factors make?

Also, does anyone have any idea on how to test an icm?

[This message has been edited by minathomas3 (edited 05-06-2007).]

You will get spark if the pcm is disconnected. Spark will happen if there is power (in your case the correct amount of power) and grounds connected on the ignition coil and position sensor harness.

All the pcm controls is body related fucntions and obviously fuel injection, which will happen if its getting a signal from the ignition modual.

Try the trick I mentioned above. The CPS should put off an AC voltage when cranking.

Other than that, it will probably just be cheaper to buy a new crank sensor than it would be to rent or buy an oscilloscope.

Better yet, just take the module off and take it to any reputible parts store and they will test it for free.

Ditto on the PCM, not neccesary for spark.

quote Originally posted by 86GT3.4DOHC: Try the trick I mentioned above. The CPS should put off an AC voltage when cranking. Other than that, it will probably just be cheaper to buy a new crank sensor than it would be to rent or buy an oscilloscope. Better yet, just take the module off and take it to any reputible parts store and they will test it for free. Ditto on the PCM, not neccesary for spark.

I am not sure exactly how to test what you are suggesting. If i remove the icm wiring harness from the cps in order to probe it with a voltometer, the cps will not be getting any power, since it is unplugged, and therefore wont be sending any signal anywhere. I think i might be missing something. Another thing is that is'nt there the risk of shorting out the sensor itself by messing with it with a voltometer. I think i might have blown my icm this way. Becuase when i was checking for +/- going to the cps through the icm wiring harness i got curious and wanted to c if there was any voltage in the 18x and 3x terminals of the icm wiring harness plug that pluged into the cps, and i think that might have actually ruined my icm.

The CPS (at least the older ones) create AC voltage as you crank. I forgot yours might be 3 wire, so im not sure, but you could try checking continuity between the hot and signal wires, if its shorted or wide open, and doesnt change even the slightest with cranking, then its probably bad.

You cannot hurt anything probing for voltage. The only way you might hurt something was if you checked for continuity. That only applies to electronic componets like the PCM or ICM, (not the CPS or any other sensor) and its not likely at that. Youd have to probe the right wires, and the meter would have to put out enough power on continuity test, its very very unlikely, but since its remotely possible, GM puts the disclaimer on thier schematics and books. Though, with the PCM in the loop you wouldnt get a usable reading anyway, so its always best to error on the side of caution and not try it accross 2 PCM pins.

Thanks 86GT3.4DOHC, im gonna check that tommorow, its my only day this week that i dont have a final on. So hopefully that will give me a clue to whether my crank sensor is functioning or not. But does anyone know of a way to test an icm before i change mine. Because to change the icm im probably going to have to drop the cradle again which means completely unhooking all the connections to the engine and that whole headache, so i really wanna make sure its busted before i put in all that work to change it.

The only way to test the ICM is to take it into a parts store and have them test it on the machine. Though I cant imagine how it could posibly neccesitate dropping the cradle just to take off the ICM. I mean if you can access the plug wires to change them, you can get the ICM out, and I sure hope you had the forsight to plan for normal maintance like that.