groundczero

iTrader: (2)

Is this a 98 corvette computer?
If so, corvettes had a steering column lock aswell as VATS.
You need to turn that off aswell.
I had this problem in my 85 mustang using the 98 vette computer and wireingharness.

garys 68

iTrader: (1)

My swap works fine. I only have the dim CEL.
Just wondering what value resistor should be added???
Trial and error? Just enough to shut the light off when it's supposed to be off?

ls1nova71

iTrader: (4)

Both my Nova and my '33 don't have check engine lights. Nova swap has around 115k on it and the '33 has 66k, never had a problem running them without it.

OldS10

Thanks again, Guys, for your input!

The guy who flashed our PCM confirmed that not only did the steering column lock have a "NO" set in the program, it was already like that when he flashed it. He DID have a thought....The PCM came out of a car with a 6 speed manual transmission and he programmed it for a 4L60E. Since Vettes have rear mounted transmissions, he said that it was kinda strange how he had to flash it, so we're going to pull it and he will restore the original "burn" and we'll try it again. I remember that when we started this project, we heard 2 different stories about the PCMs and transmissions. 1. If the PCm came from a car with a manual, you couldn't reprogram it for an automatic. 2. The other story was that you CAN reprogram it.

I am also going to try & check the wiring to see if I did anything wrong and then we will try to look at sensor signals. A friend has a Snap-On scanner that he is willing to bring to the party.

I am also going to check our LED bulbs and see if there is an integral resistor.

We'll be back!

psiconversion

iTrader: (5)

It is going to be a function of the LED (5MM, Surface Mount, Etc). I would start with a 400-ohm 1/4 watt. That should work.

Jon
PSI

aknovaman

iTrader: (7)

The led glows dim due to residual current flow from the PCM even when not enabled by the PCM and a obd2 code. It is not sufficient to illuminate a normal light bulb. When the chk engine led is in it will be very bright.

Using ohms law, 12 volts divided by 400 ohms is 30 milli-amps. Just about right for a led to be fully illuminated.

OldS10

Interesting explanation about the LED. I hadn’t looked at it quite that way. I still haven’t gotten around to checking ours for in internal resistor. It is in a T05 package & may have a resistor in the base.?. I will check it out.

On to the other problem....

We reflashed the PCM to the original Vette values (for the manual trans) and the symptoms remained the same.

We got a DTC of P1518, which seems to indicate an issue with the TAC module (per the vette manuals). We had seen that code a few days ago, but got distracted by some other ideas, and once cleared, it didn’t come back until today. We will try to follow the diagnostic tables & see where it leads, although they seem to be based on the idea that the engine runs. We DID find a badly corroded pin (A) in the TPS sensor connector (which we never disconnected). I cleaned it and checked the connection back to the TAC, along with the TAC – accelerator cable, the cruise control & brake ligh inputs to the TAC, & the throttle body motor – TAC cable, along with power & ground to the TAC module. Everything else looked to be OK, even where we integrated the two systems together.

Also noticed today that when it dies and we try cranking again, that it starts to smell like gas, indicating that it is flooding. We have also put a timing light on a plug wire while cranking and it seems to be firing. So if it is getting gas & spark, but not running, could it be the throttle body is closed completely?

We are still trying to line up some better diagnostics tools than we have.

Anyway, Thanks for listening and for your input!

psiconversion

iTrader: (5)

Correct, assuming it is a 5mm LED. If it is a surface mount, I would go with a slightly smaller resistor.

Jon
PSI

69LS1oldbird

I had the same problem on a 99 corvette that I bought. The motor had been replaced and it would start for a few seconds then die. I could do that all day. I thought that is never threw a code till I plugged in the tester and watched it. It flashed 8 codes but it never stored them. Come to find out it was a missing ground to the coil packs. I replaced that and have been driving it since. Hope ya find the issue. Since I see you have a vette motor the ground that was missing on mine is on the driver side on the very back of the head. Someone had put the ground on a painted surface and that just doesnt do. Check that out.

OldS10

Okay, Guys....
First off I checked all of the wiring that I could think of (while we had the PCM out) , to try & be sure that when I integrated the 2 systems together that I didn't make a mistake (since that was what was different from when it ran before being removed from the car it came out of). It looked relatively straight forward at the time, but I thought that I should check it anyway. I didn’t find anything, even with moving the cables a bit. Same symptoms.

Now on to the LED....I couldn’t find the ones that we got for the instrument cluster (to check for an integral resistor), so I just disconnected the line from the PCM to the LED.

Now it starts every time, runs for 5 seconds, then dies, but it starts every time. No firing & dieing. Very interesting. It sounded like it might not light correctly, but I didn’t expect it to affect the engine operation.

As far as the ignition module grounds, when we first set the engine in, I DID overlook the 2 wires to 1 lug, bolted to the rear of the driver’s side head, but found that the first day we tried to start. We had no spark at all. maybe I should check the ground again, to be sure that it is solid.

Tomorrow is another day and this has sure been a humbling experience. Humble pie is good for us, but right about now, I’d like some cherry.

And as always, THANKS for your input & time!

green96ta

iTrader: (11)

you should check all of your connections to and from your tac module. Pull all of the connectors and make sure there arent any flattened or corroded terminals. sounds like its dying because the IAC functions are not operating properly. On the metripack 100w connector, remove the black lock and check for corrosion on the terminals. They are gold plated and are less likely to corrode, but I would still check them.

psiconversion

iTrader: (5)

OldS10, when you disconnected the LED, did you replace it with a bulb?

Jon
PSI

OldS10

Yesterday I checked all of the connectors to & from the TAC. I too was wondering if the TAC or associated components was a factor. I also had removed all of the pins from the accelerator pedal end of the cable that connects it to the TAC, so that I could feed it through the firewall, so I checked the pinouts several times to make sure that I got it back together correctly, & it checked out good as well. The only pin that I found corroded was on the TPS. I don’t remember the number, but it was on the bottom of the sensor connector when looking at it from the front of the vehicle. I cleaned all of the connectors with contact cleaner and checked for broken and bent pins as well as checking continuity, but will go back and recheck them today.
I also plan on pulling the intake off of the throttle body to see if the butterfly closes all the way when it dies.

I did not replace the LED with a bulb last night. I just disconnected the wire between the LED & the PCM (pin C1-37). I figured on getting a resistor and trying it in the line, but as it was late in the evening, I just disconnected the wire where I spliced it into the old harness (original in the S10). I was also wrong about the bulb. The original bulb was NOT a 194. It was a T05 sized bulb, but can’t remember the number.

pdsq98gt

Do you have a maf on the car? If not, is the PCM set up for speed density? Maybe it's not seeing maf hz and thinking something is wrong with the t-body and shutting it.

OldS10

Back again.....

1. The factory (original) MAF & IAT are installed and connected. We disconnected the MAF and got an appropriate DTC, hooked it back up, cleared the DTC, and it didn't come back. We also graphed the MAF data and it does seem to function. We also took care to mount the MAF where it wouldn't be right after an elbow in the intake.

2. The original symptoms returned today....run 5 sec & die, then multiple times where it will fire & die. It didn’t make sense that disconnecting the MIL light would change operating symptoms....now I know why. Anyway, we DID have a P1518 DTC, and followed the troubleshooting table in the factory Vette manual and ended up at step 27, which says to replace the TAC. I was reluctant to jump on that or a bad PCM as we saw the entire package run fine in the car it came out of. When we bought it, we got everything with it, so all of these components worked well together at one time. Well, the reman Tac should be here from GM next week and we’ll see what happens.

Thanks again for all your patience & input. Have a great weekend!

gagliano7

Make sure you double check all your grounds and make sure you are grounded from body to motor.I have my battery ground going to motor and 2 body to motor grounds.Where ever you ground make sure you clean surface down to metal before attaching grounds.Most people over look grounds which are very important with computer controlled cars.

OldS10

I have been hearing how important grounds are since we started this project & have tried to keepthat in mind.We have 2 4ga. cables going from the battery to the right head & block. We then have another 4 ga' cable going from the right head to the radiator support. We also have the splice pack ground going to the right front inner fender and other grounds (such as transmission cable ground) going to the chassis. However, we will go back and check them again. You can't be too sure. Thanks!

green96ta

iTrader: (11)

sounds like you have your grounds covered. and you checked out all your dbw connections. what harness are you running? a converted factory or a new one? I really think you should try a new mass air or you should fail it out in your tuning program to force it into speed density. if your dbw or harness isnt causing the problem, with those symptoms it almost has to be your maf. there could be something else, but that is most likely.

OldS10

We are running the factory harness that came out of the same car that the engine did, a 98 Vette. We modified the harness, only to integrate it into the 89 S10 system. We didn't change the length or anything that was not necessary. When adding or removing wires, we removed pins from the underhood electrical canter connectors, and when we had to tap into any of these wires, we added pins to the appropriate cavities in the appropriate connectors, rather that splicing in wires, to minimize potential for failures. I followed the troubleshooting table in the factory shop manual until it came to a point where it said "go to step 27". When you go to step 27, it says to replace the TAC. So we ordered on3 from GM.
Also, we disconnected the MAF at one point, to force it into speed density but the symptoms remained the same.
We also haven't seen any DTCs that point to the MAF yet.

LS1MCSS

iTrader: (18)

Does that S10 have a resistor made into the key, for a factory theft lock?