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Hey guys. I'm working on an 89 RS with 305 TBI. I'm having some issues getting it started. I've done a bit of troubleshooting, and here's what I've come up with so far.
Fuel pump is working, I'm getting good constant pressure all the way up to the throttle body. If I spray starting fluid, it will fire and run, then die. So it seems there may be an issue with the injectors not firing. I've used a test light, and with the key in the RUN position, the 'A' wires to both injectors light up, and the 'B' wires both are dark. Injector fuse is good as well. I also tried unplugging the TPS to see if that got any results. Basically I'm trying to figure out if it's an electrical/signal problem, or if the injectors are just clogged/bad. Any insight, or further testing methods would be greatly appreciated. TIA.
The connecter looks like iat connecter.
KOEO check for voltage at pin B6 of the ECM you should see 5v.
If you don't get any voltage you have a issue with the pass key system.
The ECM is up under the dash on the passengers side. You can remove 2 1/4 screws to drop it down. The connecter is marked with the letters/numbers. The wire will be purple or a dark blue.
The most common issue is the key lock cylinder.
Most people measure the resistance of the key and buy a resister to install at the base of the column. There are two white wires in a orange sheathing. Unplug this connecter and solder in a resister on the body side of the harness.
No, You will still have to get the right resistance key. Measure your key's resistance and see chart. That is the key you will need. Nnless you do the mod that TunedPerformance mentioned.
So I measured the key I have, and it looks like it is a #14. A lock cylinder from local auto parts store comes with keys. One option says with anti theft null. Would one of those work? Or would I be better off doing the bypass. I'd like to do it right, but I'm also to the point that I want to get it running ASAP.
OK. I'll start with the resistor bypass and see where that gets me. So just for some clarification, if there was a problem with the key being recognized, should I see some sort of security light? And from my understanding, I thought the vat systems disabled the starter as well as the fuel pump. Both of those are working in my case. Thanks.
This is another alternative to bypass the passkey .
http://m.ebay.com/itm/191573051767?nav=SEARCHThe secerity light doesn't allways iliminate with a failure, there maybe a stored ECM code 46.
OK, so the parts I ordered came in. The key is definitely working correctly. I ran a few tests to confirm. First I disconnected the plug under the dash, engine won't even turn over. I then checked resistance coming from the column, it's consistent with the key. Then just to be sure, I stuck the correct resistor in the back of the plug from under the dash, engine turns over but doesn't fire. So I think it's safe to assume at least that part of the VATS is working correctly. I also rechecked the voltage at the ECM at terminal B6. I'm reading .32 volts. The Baker electronix link I posted above suggested that the injectors may not fire because of a faulty signal between the VATS and the BCM. Is there anything else I can check before I try that route? What are your thoughts based on my current findings? Thanks.
There is not a bcm in your car, iirc 89 is a 50hz signal at 50-60% to the ECM.
It does sound like the starter enable relay is working bye being grounded bye the passkey module.
So what would you suggest next? I read on another forum about the injectors being linked through the ignition control module. Should I pull that out and have it tested, or would you think just go straight to the bypass module I mentioned before?
Can use the fuel pump to see if the ECM is getting Distributor Reference Pulses (DRPs). Use a fuel pressure gauge if you can't hear the pump run.
Do a key-on, engine-off and note that the fuel pump runs for 2 seconds then shuts off. Should also see the fuel pressure increase as the pump runs, then drop off when it stops.
Now, give the engine a short cranking over. Did the fuel pump run again? If so then the ECM is getting DRPs. And should also fire the injectors (noid light helps here).
If the pump doesn't run at each short cranking then the ECM isn't getting DRPs. It could be the ICM or a wiring issue.
OK. The pump does run when I turn the key on. It also runs after shortly cranking the engine. The only thing not happening is the injectors firing. So I guess I'm gonna order the bypass module. Unless anyone can suggest something else to test why the injectors aren't firing.
That blue B6 wire I tested earlier is supposed to read 5v right? So since I only see .32v the signal from the vats is faulty and should be corrected by installing the bypass module?
OK. The pump does run when I turn the key on. It also runs after shortly cranking the engine. The only thing not happening is the injectors firing. So I guess I'm gonna order the bypass module. Unless anyone can suggest something else to test why the injectors aren't firing.
That blue B6 wire I tested earlier is supposed to read 5v right? So since I only see .32v the signal from the vats is faulty and should be corrected by installing the bypass module?
Check the signal with a com on hz setting.
You mentioned a few posts ago parts came in !
What parts ?
Resisters to bypass the key lock cylinder reader ?
Hz modulator ?
New lock cylinder. ?
I can't recall what years the passkey signal changed and the corisponsing vdc.
One was 30 hz other years are 50hz. The voltage between the two vdc is 2.5vdc and 5.0vdc.
Yup I ordered a set of 15 resistors. I tested each one to find out which one matched my key. Installing the correct one confirmed that my lock cylinder is working correctly.
Hey guys. Finally an update. I GOT IT RUNNING! I determined that the injectors were bad. Replaced them and it fires right up. Problem now is it won't stay running. It starts up and jumps to around 2k rpm, then drops down to normal idle for a second, jumps up to maybe 1500, then stalls out. If I try to pump the throttle to keep it running it bogs down. Almost like it's either starving for fuel or flooding. Any ideas? I can try to get a video up on YouTube tomorrow and link to it if that would help. I also replaced all spark plugs, wires, cap and rotor just to rule out a problem there. TIA.
OK, another update. Car is idling consistently now. Revs up smoothly too. But once it's under load, it wants to bog down, especially at low rpms. Every so often it gets power back and runs great. How does the advance work with these? I'm used to vacuum advances. I'm wondering if that could be the issue. I did test fuel pressure and it stays consistent at 11 or so psi throughout. Let me know what you guys think. I'll try to get a video of this as well.
05-06-2015, 05:50 PM
