Hey guys, this is my first post here as I normally find what I need through the search tool. Please provide any insight you might have into the following problem.

I have a swapped a 1998 LS1/T56 setup into my 1993 Mazda RX-7. Everything is hooked up and the car won't crank, since it's not getting spark and the injectors aren't firing when the starter is turning over. At first I thought this might have meant a bad Crank Position Sensor, so I installed a new one. This netted the same result as before. I then wired up an OBD II port into the Camaro engine wiring harness and tried to pull the codes, but the code reader displayed an error when hooked up. Thus, I concluded this meant I had a bad PCM, so I bought a tuned PCM off of Jesse Bubb figuring this would cure my problem. I hooked it up last night and went to crank the car and the battery had low voltage but was delivering spark when cranking, yet the car wouldn't crank. The battery was then placed the charger to let it receive a decent charge before trying again. When I went to go crank the car again with a full charge there was no spark while the starter was turning over and you couldn't here any clicking of the injectors. You can here the fuel pump kick on when the key is in the ignition and there is fuel going to the rails. The pink wire at each ignition harness has 12V power while cranking and the black at the harness has good ground continuity. Last but not least, when I went to pull the codes off of the new PCM, I got another error message.

One thing it does do, is it sparks when turned to the on position and it sparks again, when the car is turned off. Is this normal for a 1999 PCM to do this as my buddy's 1997 C5 doesn't do this?

I am now a little stumped since I have tried two CPS's and PCM's and experiencing the same problems. Has anyone ever encountered something similar?

Thanks in advance!

 

Coil packs turned upside down? I heard it was easy to do to the 98's.

 

The coil packs are correct, but I really appreciate the suggestion Dale. Let me know if you can think of anything else.

 

I swapped a 98 ls1 into my 96 firebird, i had the same issue. My car would only fire when the switch was being released, and it was turning back toward the on position from the start position. i also got spart in the on position. SO, i slapped a pushbutton start in the cigarette lighter, turned the key to on, gave her a push, and she fired right up. just a suggestion, i know that it worked for me and i was in your situation for several days and couldn't figure any other way to start it up. think i got the push button for like 10 bucks at autozone, and nobody really sees it in the lighter, and you still have to have the key in and turned to on before it would start. hope that helps you out, but as far as the actual problem fix, please let me know if you figure it out.

 

sounds like your ignition switch isnt wired correctly, or it is malfunctioning. the switch should provide power to your ignition in the start and ON positions.

 

Just to clarify, you do have a 98 motor with a 99 PCM and harness right? If you just plugged the 99 PCM into the 98 harness you will have to re-pin the harness to match the newer stype PCM. I've got a 93 RX7 that is getting a 98 motor/T56 and 99 PCM/harness as well BTW. I'm nowhere near as far along as you though.

 

Well i had a guy from tech re pin my harness, and everything else works. i do get power when it is in the start position, but only when releasing the switch back to on. i had a gm dealer change my ignition switch twice, and still the same result. i'm honestly not sure what the problem is, but the push button start got me around the problem, and it works great. i'll probably just keep the button. but thanks for the info.

 

Skele4door,

I do have a 1999 F-Body PCM and wiring harness connected to a 1998 Camaro Z-28 LS1/T56, so the pinning is correct. I guess I could try and short the starter power to its solenoid, which would be similar to wiring in a "Start" button, just to see if that would work.


Thanks for all the ideas guys, please keep them coming!

Brad

 

Did you ever figure it out?

 

I had to use a ford starter soleniod because I was not getting enough current to my starter to pull the brushes in with the mazda wiring. Search for spaceman_spiff and starter at torquecentral.

To test it... put the key in the on position, and take a wire and jumper the big power of the starter to the little post (start signal) and see if it turns over....

-Jason

PS - how is the voltage on your battery? Also, get an ammeter and check the resistance from your block to the frame to make sure you have a GOOD ground.

 

well..........

 

The block is well grounded, as there is no voltage drop from the the positive battery terminal when using the block as the ground/negative. I have two grounds hooked up on the BCM side of the LS1 wiring harness and the two ring terminals off of the wiring harness which go to the back of the driverside head are properly grounded too. Thus, I believe I have a good assortment of grounds. However, I could probably add a tranny to chassis ground, just to be safe.

I haven't been able to add the remote starter (jump the starter) yet, as my work schedule is crazy, but I will be hooking that up tonight and will fill everyone in on those results.

THANKS!
Brad

 

It cranked!!! The hot, constant wire to the PCM wansn't making a good connection and I had the fuel return and the feed reversed on '99+ Corvette Fuel Filter.

Thanks for all the suggestions.

Man does this thing sound mean with open longtubes!

 

glad to hear you got it going! i know the feeling of hearing it run the firs time after all that work! congrats

 

That Great, they do sound mean!

 

Glad you got it running! Electrical demons are a bitch, but often provide the greatest sense of accomplishment when solved