Hello all....I am doing some tests with a test light using a manual for the tpi and it's asking me to probe the relay harness from terminal "a" to "f" and I don't understand how to do that? Also how do you jump terminals with a 15amp fused jumper wire? There are tests for everything but I don't understand certain tasks they are asking me to do.

 

If you look at the bottom of the relay, the relay and the harness should have the various terminals marked with letter codes. If it's a two wire, it'll be A & B. If it's three wire, it'll be A, B, & C. and so on.

A 15amp fused jumper wire, is just a wire with a 15amp fuse in the middle so if you short something it'll pop the fuse without causing damage.

 

Example is for our fan relays, but may be generally applied to most automotive relays.
D and F are the relay coil terminals.
Battery power is supplied to terminal D.
Terminal F is grounded to energize the relay.
The probe (while connected to ground) should light and the relay should energize (clicking sound) and any citcuit it controls e.g. fan should operate when probing terminal F, if it doesn't the coil is open, or no power is present at terminal D.
Terminal E is the power supply terminal for the circuit, or device being controlled.
Terminal A will have power when the relay is energized.

 

Hello, it says to jump terminals "A" and "E" with a jumper wire for one test, how do I jumper "A" and "E"? ...the other test says to probe the relay terminals "A" to "F" . Does this mean to probe each terminal one by one? Any help is appreciated.

 

You take the relay off and put the jumper wire in the relay plug between the terminals that go to those pins on the relay

 

LS7Roc drove with code 36(MAF Burn-off Relay Failure) for a year, and now it won't start. I believe he's testing that relay. I told him to try and disconnect the MAF sensor....No Start on limp mode! With the burn-off relay disconnected it should start, with the MAF sensor it should've started on limp mode. I believe it could be his ECM is gone! Or it could be many other things........!

 

I tried disconnecting all that stuff and she still doesn't fire up. I got this TPI manual that has all kinds of tests but I am no mechanic so slowly with the help of some great people online, I should figure it out.

 

Hey Vette, with the one test is says to "probe from relay harness terminal "A" to "F", does test light illuminate? So try one by one or...???

 

Hi Vette, so jumpering the terminals would be like jumping a to b for the code scan right? But at the same time it says to probe it with the test light?? Acually, it just says to probe "A" to "F" with the test light, says nothing about jumpering the two...very confused my friend.

 

Jumpering would be jumping from one wire or terminal to another with a piece of wire, just like jumper cables to start a car with a weak battery.

Probing means checking the wires from the back side... Sometimes it means piercing the insulation on the wire, but I wouldn't recommend that since it's hard on the harness. Usually you can probe the terminals from the wire side of the plug.

 

Are you diagnosing a no start as y84pauloflondon stated?
The ECM doesn't activate the burn-off relay until the engine is turned off so it wouldn't be the cause of a no start.

Quote:

Due to contaminates in the atmosphere a residue may build up on the MAF sensor sensing wire. To maintain an accurate reading from the sensor, a "burn-off' cycle will occur when the ignition is turned off after the engine had been running a specified amount of time and engine warmed up.

Even if you had a code 36 before the no start, to diagnose a code 36 per the manual requires the ECM to be in closed loop mode, for that the engine must be running.

 

I'm trying to do the "cranks but won't start" tests in the manual. The manual says to "with a test light, probe fuel pump relay terminals "A" to "F" which to me means probing all of them one by one. I am not sure but is this what it means to do?

 

So, i assume you don't hear the fuel pump prime when the ignition is turned to run/start?

 

No
It means probe from A to F terminals , not between all of them

 

The reason I said it may be his ECM is because he said he disconnected the MAF sensor and it still did NOT start! Very early into my own "No Start" problem, Chevy8588 felt that my ECM may have been MY problem, which is why I'm saying it could be his(LS7Roc) ECM. He's just starting to diagnose the problem, I'm just throwing out some ideas....

 

LS7Roc sent me a PM stating that he can hear his fuel pump come On and he has fuel at the rail. I asked him what was the psi at the rail.....I'm still waiting for an anwser!!!

Regarding Code 36, I don't know why his manual is telling him to test the fuel pump......It doesn't make sence!

 

Judging from your other threads on this matter.
In my opinion your going in the wrong direction, you car won't start because you most likely have no reference pulse from the distributor.
Do this simple test, hold a finger on a fuel injector while a friend cranks the motor over, you should feel a steady clicking if not your ignition module is bad.
If that is the case, all the fuel pressure in the world won't start the car because the injectors are not squirting any fuel into the engine.

 

I have spark at the wires and at the coil wire, does that matter or can the module still be bad? Is the module replaceable without a new distributor?

 

yes the module is replaceable, remove the distributor cap, it's held in with 2 screws, in addition to spark it also tells the injectors when to open and close.
Take it out and bring it to auto zone they can test it.

 

Hey John, I've been reading about a hall effect sensor or some pickup coil that is not replaceable on the distributor. This could also be my problem I think, that sensor and/or coil tells the injectors when to shoot gas as well right? I appreciate your help.

 

Try the ignition module first, you can replace that.
It would probably be easier to replace the whole distributor than to mess with pick up coils and stuff.

 

I replaced the ignition module and still no start. Just cranks. BTW, is there anyway to remove my other threads on the no start topic?

 

The ignition control module provides a pulse to the spark coil and a pulse (distributor reference pulse) to the ECM which it uses to enable the firing of the injectors.
Unfortunately the VATS system can also tell the ECM to enable/disable the injectors.
Using starting fluid should cause the engine to run for a few seconds in which case you need to determine what is preventing the ECM from firing the injectors.
Is it the ECM? I and y84pauloflondon suspect it to be. But, because it fix his no start you may not be so lucky. Besides components you still have wiring to consider.

 

Good to see you again rgarcia63! My No Start was due to a bad MAF Power Relay...Not ECM.

The reason I think it could be his ECM is, even if his MAF sensor and MAF burn-off relay were bad, having BOTH disconnected his car should have started up on Limp Mode......it did not. And he had code 36 for a year.

WileECoyoteSr somewhat had the problem, but his car WOULD start from time to time! LS7Roc's car has not started at ALL!

Could he(LS7Roc) put a test light to the injector and have a buddy try starting it to see IF the Test Light lights up????? Can this be done????

Or maybe 1 or more of the fuel injectors has failed, he could try to ohm test them!!!!

 

Doesn't the pickup coil also control the injectors? I don't have VATS and there is spark and fuel...could the pu coil be the problem?

 

I ohmed the injectors. All were 16.1/16.2.

 

Still it can be the ECM injector drivers, injectors fuses, and or wiring.

"Test Light" it's called a Noid light and plugs into the injector connector.

I bought a set of 5 that covers most if not all makes.

If mention things he has already done, it's because I don't know what all has been done to date.

 

Ok, you don't have VATS, but the ECM still drives the injectors (turns them of & on) using signals from the distributor ignition module that are conditioned from the raw AC sine wave signal produced by the pickup coil. Unless the ignition module has 2 seperate circuits; one for the spark plug coil (you have spark so that one is working) and one for the ECM. Then, it's possible that the one circuit for the ECM is dead.

But, you've already replaced the ICM, or had it tested, right?

 

Yes I replaced the ignition module. The pickup coil looks real bad especially the connectors. ???

 

I just replaced the pickup coil. Still just cranks.

 

Did you get a noid light to test the injector signal from the ECM at the injector connector?

 

I don't have a noid light. I ohmed the injectors and they were good. I did a test to check if the injectors blink while cranking and no blink. I replaced the pickup coil and module and still nothing. I have no spark but I smell gas when cranking. Fuel at the rail is good too. No spark though.

 

So now you have NO spark at the PLUGS!!! And How were you checking for spark before???

 

I think that the magnetic pickup inside your distributor has gone bad just like WileECoyoteSR's did. It BASICALLY works as a camshaft positioning sensor.

 

He has already done that.

Check for 12 volts on the pink wire at the coil with the key in the run/start position.

A test light won't work for testing the injector signal. Get it sparking again, first.

 

I replaced my ignition coil and it started for a second and died. When I did the pickup coil, I was careful to mark the positions so I can reinstall it without messing the timing but I don't think I did a very good job at that. I don't have a timing light so is there anything I can do right now without one? Maybe to get it going at least?

 

rgarcia63- [WileEcoyoteSR: "That hall effect sensor suggestion is interesting but one of the first things I did was replace the coil and the ignition module. I did not replace the magnetic apparatus on the distributor the name of which I cannot recall and as much rain as is coming down I'm not trudging to the garage to get the manual. Is that piece plugged into the ignition module capable of telling the injectors not to fire?????" :End Quote- Another Won't Start story/post#33]

[Chevy8588: "that magnetic apparatus is you hall effect sensor (not sure if that's what is was called back then but that's what they called them on later cars) it tells your ECM that the engine is spinning and to fire the injectors, it BASICALLY works as a camshaft positioning sensor." End Quote- Another Won't Start story/post#34]

From what I can understand, the "magnetic pickup/apparatus" is NOT the same as the ignition module. WileE ended up buying a new OEM distributor which fixed his No Start issue!

 

Do this, remove the no 1 spark plug (dr side front) stuff a shop rag in the hole, not all the way in, just far enough to block the hole, now disconnect the coil and bump the motor with the starter untill the shop rag pops out of the hole and don't go any further.
you should now be fairly close to tdc. Now mark the position of the no 1 plug wire on the dist cap, (put a piece of tape on the plenum) remove the cap, the rotor should be pointing close to the mark, if it's way off readjust it.
Put the cap back on and the spark plug back in and see what happens.
Will need to aquire a timing light to fine tune it tho.

 

LS7Roc- have you replaced the MAF sensor??? 7 yrs ago, I had a No Start issue due to a bad MAF sensor. And since your burn-off relay wasn't working to keep that sensor clean, maybe the dust killed your sensor!!!!- Just another thought!

 

Do I need to also disconnect the est timing connector? Also, how would I readjust the rotor? Or do you mean by readjusting acually turning the distributor?

 

That's a good idea on "how to", but a buddy and I just did this to his 91 Syclone, and we used a wrench to turn over the engine to TDC. And your not pumping gas into engine this way either.(slow, steady, and accurite)

 

Before the car died, it would run better with the maf sensor disconnected, not great but better. My car now wants to start but I believe the timing is messed.

 

So you've been driving on "limp mode" for a year, give or take?!

 

You may need to pull the dist up far enough to disengage the drive gear, then turn the rotor and drop it back down.
Bear in mind that the shaft will turn when you re-engage it so allow a little space for that.

no need to disconnect the est conn
You only need to unplug the coil so the car wont try to start when you bump the starter over.

As pointed out above, yoiu could also disconnect the ignition module to disable the fuel injectors.

 

No, just tried it once or twice when I got the code. The car would run but it felt like a miss or something...I have to change the maf when I get the money.

 

-A remanufactored MAF sensor- $100.00-$200.00
- AC Delco Burn-off relay(part#10094701)- $10-$15

You REALLY need to get both if you want your car to start and run right!

 

Okay, I tried to adjust the timing and now the car won't even try to start...just cranks. I obviously made the timing worse. I'll try again or maybe I'll wait to buy a timing light, or borrow one. The timing tag above the crank is very corroded. Nothing but trouble I tell ya! If I hand crank it to TDC, what would I feel as far as compression with my finger on the spark plug hole??

 

Hissing(air being pushed out) during compression stroke, and you would feel suction during intake stroke.

 

Okay, so as I HAND crank it, I would feel some air being pushed out?

 

Correct!