Where to go from here ?

[1984 t-type]

New cam sensor and cap installed correctly, new crank sensor installed correctly, new 86-87 ignition module, new Caspers module bracket and wiring harness adapters. Cranks strong but no spark, previously had no injector pulse either but I have not retested that since I installed the new module. I'm at a lost ! I have read reread and asked questions I just can't get it right. What else could cause this issue ? Please help

 

[1984 t-type]

Any ideas what this connector is for ?

 

[NorCalTurbos]

New cam sensor and cap installed correctly, new crank sensor installed correctly, new 86-87 ignition module, new Caspers module bracket and wiring harness adapters. Cranks strong but no spark, previously had no injector pulse either but I have not retested that since I installed the new module. I'm at a lost ! I have read reread and asked questions I just can't get it right. What else could cause this issue ? Please help

Are you 100% sure it's not getting any spark 0 none at all ? Have you checked out the ECM? Also the ignition switch on the column. I had a bad one and my car wouldn't start and my windows wouldn't budge. Long story short $18 bucks and I was back happy

 

[1984 t-type]

positive its not getting spark, ecm is next on my list im just getting tired of throwing parts at it. never thought about the ignition switch may give that a try first although my windows do work, slow as hell but they work lol

 

[BRAD_PADGETT]

positive its not getting spark, ecm is next on my list im just getting tired of throwing parts at it. never thought about the ignition switch may give that a try first although my windows do work, slow as hell but they work lol

STOP. Quit throwing money at the car. Our cars are really no different than the 86/87. The advice from the 86/87 world is identical to our cars. Take a break and get a scan tool. Read about not start issues. There are plenty of posts on this. Your car and mine are almost 30 years old and electrical issues can really get into your head. Remember- these are one of the first tuner cars.

 

[1984 t-type]

I can borrow a scan tool from a friend at work but can that help me if I can't get the car to start ? Read vortex buicks site 3 times over and posted a question about the no start tree here but no one could help me ( I suppose ) from what I gathered through my research and the no start tree it pointed to a bad ignition module but that made no difference. Everyone says read and search but I'm on my second month of that and just loosing patience now.

 

[O SO LO]

NO-START TEST

Below is a series of tests to troubleshoot a 'no-start' condition. (I basically reprinted this from a GM troubleshooting flowchart, hopefully it will be of some help!)

Below are links to repair manual pictures to reference from:

ECM Plug
Sensor Plugs

You'll need to get at the ECM and the cam & crank sensors to do some voltage tests. If you have a NEEDLE type voltmeter, it may work better for these tests, as it will visibly "swing" when the sensor switches open & close (IF they're working okay!)

Here goes:

First, test your meter and ground! (see ECM Plug) Check connection A-6, "ign, ECM fuse" for 12 volts. (for ALL tests, BE SURE the negative lead of the voltmeter is connected to a GOOD GROUND!)

#1- (see ECM Plug) With the key off, disconnect the ECM A-B connector. With the positive lead of the voltmeter, probe the B-5 connection (highlighted yellow, this is the crank sensor signal) Crank the engine and watch the meter...you should have varying voltage from 1 to 7 volts.
If NOT okay, proceed to #2.
If you ARE seeing correct voltage, your cam & crank sensors are okay, and your coil and/or ignition module may be the problem! You need to loosen the coilpack, and check the BLUE wire for 12 volts, key on. If it DOES have 12 volts, then the problem is likely the ignition module.

#2- now probe the A-11 connection... (highlighted green, this is the cam sensor signal). Crank the engine...you should have varying voltage from 1 to 9 volts.
If it IS okay, THE CAM SENSOR IS FINE, AND YOU ONLY NEED TO TEST THE CRANK SENSOR IN ALL FURTHER TESTS!
If it's NOT okay, there's no cam sensor signal!

Plug the ECM connector back in, and head for the sensors!

#3 (see "Sensor Plug") Unplug the cam sensor plug. Turn the key "ON" ...On the MODULE SIDE of the plug, probe the "A" wire for voltage, after which probe the "B" wire for voltage. You should have between 5 and 11 volts on BOTH wires.
If you ARE seeing correct voltage, THEN: with the negative lead of the voltmeter, probe the "C" wire, and with the positive lead probe the "A" wire. You should have between 5 and 11 volts. Note the results, then REPEAT THIS TEST WITH THE CRANK SENSOR PLUG!

If ANY of the sensor plug tests FAILED, you have a probably ignition module problem...
If ALL the sensor plug tests PASSED, then PLUG IN the sensor plugs, and proceed:

#4. Test the cam sensor: Probe the "B" wire of the cam sensor, then crank the engine and watch the meter. You SHOULD have varying voltage between 1/2 and 9 volts. REPEAT THIS TEST WITH THE CRANK SENSOR!

If either sensor fails this test, then it's possible that sensor is bad! If they PASS this test, it's likely the ignition module, or the connections TO the ignition module are bad)

Hope this makes sense!

 

[1984 t-type]

I tried all that, that's the info i found on vortex buicks, my issue was when I probed at the ecm and cranked I saw voltage but it was not varying just steady voltage. I posted that in a thread I started here but no one said if this was normal or not, a did do the test using a fluke dvm so I will run out today and pick up a cheap needle style one and retry the test to see if I can actually see the voltage varying. if it still is just constant voltage on b5 while cranking is this a issue ?

 

[Jerryl]

. . . probed at the ecm and cranked I saw voltage but it was not varying just steady voltage. I posted that in a thread I started here but no one said if this was normal or not, a did do the test using a fluke dvm so I will run out today and pick up a cheap needle style one and retry the test to see if I can actually see the voltage varying. if it still is just constant voltage on b5 while cranking is this a issue ?

A digital VOM won't show the pulsing. It's too fast, which is why the needle style works better. Best is a graphing meter or scope. As a general rule, Steady voltage =no pulse=no start.

 

[1984 t-type]

Gonna run up to sears when they open today and pick up a analog meter today. So let's say I still have steady voltage what would cause that

 

[Jerryl]

Gonna run up to sears when they open today and pick up a analog meter today. So let's say I still have steady voltage what would cause that

Edited.

B5 should definitely pulse. Pick one up at a pawn shop.

Before you buy . .
Verify resistance from module to ecm connection.
Very possibly cam sensor issue.

 

[1984 t-type]

Do you know which pins I need to probe to verify the resistance ? Bought a meter and now I can see that the voltage is varying

 

[Jerryl]

If voltage varies, you should be ok. Not sure which pin, but it's the purple/white wire. Verify voltage at the cam sensor.

 

[1984 t-type]

Nick Micale guided me through the cam sensor install and it's new so I'm confident that it's right, cam and crank sensors both have power at a&b and good ground on c. All of what I have read points towards a bad ignition module but I'm on my second new one. Have a guy local to me coming by with a known good used one off his car tomorrow along with a ECM so I will see where that gets me.

 

[MeanBuicks]

I wouldn't be surprised if it's the new module. Years ago I put two modules from AutoZone on my '87 and continued getting no start. Got my money back and bought an Echlin brand from Napa. Problem solved.

 

[NorCalTurbos]

You're getting close keep us updated on the results