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New version(?) of Vette won't start problem

T

Tuck

Guest
I looked through all of the past topics and found similar problems but none that could help so here goes:

Yesterday my alternator went out. I replaced it twice (I seemed to be making a habit of this twice thing-I had to do a heater core twice about 2 weeks ago) because the first replacement was only putting out about 11.5 volts. Not a problem-alternator was a piece of cake. The problem began because I had ran the battery down and had to hook a charger up to it (had battery checked to make sure it was good). I left the bat in the car but disconnected the termnals for charging. After getting the second alternator in and while hooking the battery back up, I noticed one of the fused links connected to a red wire going to the battery (that had apparently been repaired before I bought it) had seperated at the connector. There was not enough wire left to repair it so I went to the dealer and got a new connector and reconstucted this part of the wiring. Basically it consisted of two seperate circuits. The original had a red wire going straight to the battery terminal and one going to a single wire connector to a fusible link going back to the firewall and to the fuel pump relay (I think). Both of these wires were connected by a black covered butt connector and made a joint for two seperate fusible links that went down by the exhaust mainifold area and to a two-wire GM connector. I reconstucted this the best I could-using a new male end two wire connector, about 6 inches of fusible link and the old single wire connnector on the other end. I can see no way that this should not be a suitable replacement for the old wiring.

However, now I can not get my vette to start. I believe I have narrowed it down to being a fuel flow problem but can't figure out why. I have replaced the fuel pump relay-but I don't think that is the problem since when I checked I don't have power going to the relay plug (key on or off). I also don't hear the fuel pump start up when I turn the key on but I know it is good because I ran a hot wire from the bat to the ALCL under the dash and the fuel pump runs fine. Don't have hardware right now to check fuel pressure but have help and guages coming this weekend. The car does fire momentarily when I spray starter fluid in to the butterflies.

FYI the car ran fine yesterday morning when I was test driving the first alternator and the no start condition did not occur until I tried to test the second aternator and after the wiring repair.

Also one other thing to mention is that my "Service Engine" light does not come on (it worked a couple of weeks ago) I found this out when I looked for trouble codes. Before you ask, yes I pulled the dash apart and checked the bulb and it was fine.

Also took the time to check the usual stuff, coil. rotor, ICM.

What I am suspecting is that there is another sensor that I damaged somehow electrically when I was working on the alternator, charging the battery, are fixing the wiring, that may also be causing the check engine light to malfunction. Either that or I screwed up the ECM in the process.

Any ideas or words of wisdom would be greatly appreciated.
 
Phew

Well great observations....... Can you take a PIX of the repair area?

It will help me zero in on the problem with you...

BUT the key on.... should let the ECM fire up the fuel relay for 3-5 seconds...

And you state this doesn't happen.

I would check if you have power to the following points.

1) The Oil pressure switch ( Orange & red wire on top...Orange should be hot)

2) ECM fuse

3) Injector's


and IF #1 is hot...jump it with a paperclip and see if the pump winds up & the car will start.


Did you use crimp connections or solder?

I ( once ) did a crimp and clean missed the wire and bit on the insulation.. took me a FEW minutes of DOH! time.

I can help I have FULL schematics of that beast.....


Vig!
 
You didn't........

Buy a PEP BOYS alt....did you?
 
Thanks for the help Vigman.

The photo will be tough until next weekend-have to borrow a digital camera from work and will be out of town until end of week. Hope to have it solved by then, but if not will get you a photo online probably by Friday.

I used crimp connectors but I did a continuity check with my multi-meter and seem to have a good connections all around but will double check again.

As far as the alternator, I did not get either at Pep Boys-the first was from Checker and apparently was the last of it's kind in the region so I had to get a refund when I verified it was bad and got the second one at NAPA. Both were Delco Remy's though.

Give me some time to check for power at the points you mentioned and will get back to you with the info.
 
Update

Vigman,
I may (repeat may) have found the problem.

In my first posting I mentioned a black covered butt connector-

"Both of these wires were connected by a black covered butt connector and made a joint for two seperate fusible links that went down by the exhaust mainifold area and to a two-wire GM connector."

Working on a hunch from my ex brother-in-law I actually dug the parts out of the trash and crushed this connector and found inside (like he said) that all four wires were actually soildered together I had been treating this like they were two seperate circuits.

Let me correct this and see what happens and get back to ya. (I am praying that it is this simple).

Tuck
 
Update 2

Vigman:

Nope the miswiring did not fix it-I am hoping it did not cause a bigger problem.

As far as the power checks

1. I can not locate the oil pressure switch-book shows it in a diagram by the distributor (no photo) but I am not sure exactly what it looks like to be honest-can you give me some info on this.

2. I have 12+ volts at the fuse to the ECM.

3. Not exactly sure where to check for power on the injectors either.

I did check the wires going to the fuel pump relay which I replaced last night and it does not seem right.

The results were the same regardless of wether or not the ignition was on:

A: 12+ volts
B: Grounded
C: Grounded
D: Grounded
E: Grounded
(Verified ground by doing multimeter continuity check with neg bat terminal)

I can jump D & E and get the fuel pump to fire up (like the book says)

Shouldn't I be getting 12 volts on at least one of the other wires when the key is on? I am thinking E should be hot with the key on and maybe C also.

This would explain why the fuel pump is not firing up (without the D to E jumper).

Also I am not getting a spark at the plugs now- I thought I was before because it seem to fire for a short time when I used starting fuid in the butterflies. I pulled a plug and reseated it in the plug wire, held it close to one of the exhaust manifold bolts why my neighbor tried to crank it and there was no arcing.

I am leaning toward the ECM being bad.

Any thoughts or other checks I can do other than the Oil pressure switch & injector power check?

Thanks
 
Checks for power

Do the headlight motors/headlights work?

Do you have power to pin A of the fuel pump relay?


Does the fan for the blower (AC) work?

And the car cranks... right?


( Primary power busses )


Vig!
 
In the fuse box

With the key on......


You have power on BOTH sides of the ECM fuse

( sorry but I have to ask... some people DONT get it... and I don't know your level of technical expertise... so I apologize in advance)

and there are 2 other fuses Inj #1 & #2
 
I believe your fusible links are

D & E

D controls the coolant fan relay

E is the Aux fan relay

these go to to the battery positive ( as you described earlier)

There is one more though

H... which is close to the other two... but heads twds the firewall and goes to the

Always HOT from Battery
Orange wires

Oil pressure switch
Fuel pump relay
Mass burnoff relay
Mass burnoff CONTROL relay

ECM DIRECT 2 places
Connector C2 ( pin B1) Orange
Connector C1 ( pin C16) Orange

I smell a fish HERE!


Vig!
 
AND......

The H link goes in one side red..... then turns Orange ( on the other side of that black plastic moulded shell)


Vig!
 
Further

the red wire on the side of the disrtib marked BATT see if that's hot too!



That should keep ya busy!


Vig!
 
A/C fan and blower work.
Headlights and motor work.
Car cranks fine.

No I do not have power to pin A of the fuel pump relay-I said I did in an ealier post but when I double checked the wiring schematics I was mistaken-it was pin E (Orange wire) that I have power to. As I mentioned earlier I can jump D & E and get the fuel pump to power up.

As it stands right now, I have no spark at the plugs, injectors do not seem to be working, and I can crank it until the battery goes down but it will not start. Also, if it helps I still don't have a check engine light so I can not check for trouble codes.

We did pull the ECM out and pop it open. No sign of (or smell) of anything burned. My Brother-in-law (BIL) who is a full time honda guru and a mustang guy on the side says that is a good indication that there is nothing wrong with the ECM. He believes it may be an ignition switch but I am not convinced. Not that I have any background for doubting him-it just doesn't make sense to me-but I have been wrong before.
 
Oil pressure switch

Is on top of the Oil pressure sender...

So Drivers side
near wiper motor base
Near firewall
look at base of Distributor

You will see a BIG silver bullet thing...
( that's the oil pressure sender... not what you want) but look up a bit you will see a switch/ sender looking device with a red & orange wire sticking UP... that's the oil Pressure switch.... It closes when the oil is over 4 PSI. The orange is ALWAYS HOT.

Now about the 2 fusible links..........

You should have 1 big red wire coming off the batt terminal... that went to Both of these burnt links, all of em need to be hot!

and check the wire coming out of the actual batt post... sometimes they break... but the insulation remains.. so the wire looks cool visually... but cannot pass any current!


Vig!
 
PIN E ORANGE!!!!!!!

According to MY shop manual 1988

The ORANGE wire is hot and it's pin A

Maybe your year is slightly different... but I doubt it. The Fan relay yeah.. but NOT the fuel pump relay.

I'll bet One of the link repairs is not correct OR the H link is bad... but if you have power to the fuel pump.. that MAY blow my theory.


Continue....

More posts to follow!

Vig!
 
In a 1986

DO you have a big cluster of wires that junction to a black plastic cage by the battery near firewall?

The headlights mean Links F & G are good

The blower means link K ( under car ) is good


Oh... do you know the sender wire to ground to get the main cooling fan to run?

If the fan runs... that will eliminate link D

Vig!
 
Gm ARRGH Fuel pump wiring

Ok the 86 pin E is correct!
and it is orange!
Just dug up my other book!
Vig!
 
FYI I am a rookie so keep that in mind. I can turn a wrench and I do communications for a living so I have some experience reading wiring diagrams etc but doing this on a car is new to me.

Yes with the key on I have power to both side of the ECM, INJ1 & INJ2 fuses.

I am pretty sure I know about the D, E & H fusible links. I am pretty sure E is the link that started this mess. I had problems with it before and it caused my fan not to come on. Finally got it figured out and repaired but it came disconnected. I am pretty sure D & E are the 2 fusible links I replaced (see my initial posts) and they were conected together in a solid butt connector. On the end towards the batttery one went to the terminal and the other went to a single wire connector which connected to another fusible link-which should be H. All of those are good (now) also I beleive H ends up coming out at pin E (orange wire)of the fuel pump relay and I have power there (key on or off) all the time.

The red wire marked BAT going to the distrib is hot only when the key is on.

Not sure what you are saying about the items below:

Oil pressure switch
Fuel pump relay
Mass burnoff relay
Mass burnoff CONTROL relay

ECM DIRECT 2 places
Connector C2 ( pin B1) Orange
Connector C1 ( pin C16) Orange

Are these the possible problems?
 
Vigman

"Oh... do you know the sender wire to ground to get the main cooling fan to run?

If the fan runs... that will eliminate link D "

No I am not sure which wire I need to ground to check the fan. I tried turning the A/C on-I thought it ran all the time with the A/C on but I must be mistaken-may have something to do with the engine not running and being hot.
 
Previous post on coolin fan control

Depending on the Ilk.....

Either between cyl 6&8 Pass side or 1&3 Drivers side there is a sender......

It has a ROUND pin connection with a ( If memory serves ) a Green... or green & White wire. This line grounds when the engine is at 232 ( ish ) degrees.

Turn the key on.... get a test light


This wire ( Green/White) is the ground side of the relay. So with the wire pulled that line should show HOT IF the coil of the relay has power.

Remember it's the connector with the ROUND PIN not the spade lug... the spade lug is the temp gauge.

Ground the Green/ White wire

Does the relay go click?

Does the fan spin?

If the relay goes CLICK and the fan dosen't spin

Check the red wire going to the fan.. WITH the relay grounded!

Is the RED line HOT?

If the RED wire going to the FAN is hot but the fan dosent spin..... the fan is TOAST! OR the fan ground is bad ( typically the fan ground is OK)

If the red line ISNT hot...pull the relay and find the 2 BIG wires in the relay socket... Red & Orange..... see if the ORANGE is HOT... If not.. you have a burnt fusible link.... I will have to check the book for further info.


Hope this helps
( Did most from memory.. so it might be a tad inacurate ( Wire Colors)... but the base theory is correct)

Vig!
 

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