Ignition Problem-o (2.9L Owners Unite!)

SuperRob · Aug 20, 2007

Ok, so I have another thread going in the V6 forum, regarding head swaps, but at this point I realize that this is no longer an engine question...but an electrical one.

I just swapped the heads on my 89 2.9L. after I got everything all back together it wouldnt start. I'm going to try to explain all the different conditions that I've had here.

I've double checked:
The distributor is timed correctly to the crank (not 180 out).
Plug wires are all connected in the right order.

I need to know:

The orange wire coming out of the harness that plugs into the distributor - WHERE DOES IT BOLT TO?

The braided ground strap that comes off the drivers side head at the back - WHERE DOES IT BOLT TO?

The Mainground strap on the truck from the negative battery post, runs down to the frame rail, and then goes somewhere. for the past 3 years this strap has done NOTHING for me because it was actually just looped back to the negative battery post (I know I know....dont ask how or why, just know that up till now however this mess was sorted out, it worked!) Where does that Ground Strap bolt on to?

I set the crank to 10 degrees BTDC, hooked up a timing light, and turned the distributor till the lite went flashed. tightened the distributor down so it wouldnt move unless I moved it.

Then when I try to crank the engine over, the timing light doesnt flash at all. HOWEVER, when I pull the plug out, and ground it on the intake or exhaust manifold and crank again, I get spark on the plug, but no flashing of the timing light. I then tested the timing light on another car and it works fine. ALSO, the spark that I get from the plug is not as good as I'd like, its a little bit yellow instead of bright white/blue. I'm attributing this to the poor ground that I evidently must have on the engine.

So to get things started here....from the beginning, Where do those 3 wires Start, and Terminate? I"m looking for 100% confidence in the answers guys....as in you went and looked at your 2.9L and chased the wires! As you can tell, guessing hasnt worked yet!!!

Thanks!

kunar · Aug 20, 2007

SuperRob said:
The orange wire coming out of the harness that plugs into the distributor - WHERE DOES IT BOLT TO?

The braided ground strap that comes off the drivers side head at the back - WHERE DOES IT BOLT TO?

The Mainground strap on the truck from the negative battery post, runs down to the frame rail, and then goes somewhere. for the past 3 years this strap has done NOTHING for me because it was actually just looped back to the negative battery post (I know I know....dont ask how or why, just know that up till now however this mess was sorted out, it worked!) Where does that Ground Strap bolt on to?

the first one goes to the back of the pass. side head, its pretty low in the back. the second one goes to a stud that holds the wiper motor on, theres a nut that holds the ground on. the third goes from the frame rail, to the engine block on the pass side. hope this helps

edit: i would bet the orange one grounds the distributor, not the head. thats probably making a spark problem for you. the engine ground may be contributing to the same problem. the one on the wiper motor shouldnt affect the engine at all i wouldnt think

SuperRob · Aug 20, 2007

Ok...so I've decided that I know where the orange one goes...but thats not where it was when i took the engine apart...which means its just one more thing that was done wrong before....

Can you be more specific as to where on the block the main ground strap goes to?

Appreciate the help BIG TIME.

Jspafford · Aug 20, 2007

I don't think it matters to much which hole you bolt it into. There are a few threaded holes cast into the block, pick the cleanest one and bolt it on.

kunar · Aug 21, 2007

Jspafford said:
I don't think it matters to much which hole you bolt it into. There are a few threaded holes cast into the block, pick the cleanest one and bolt it on.

pretty much, yeah. but really it is on the pass side, close to level with the motor mount bolts, but about 6" or so back toward the back. (this is from memory, i can really double check if you need me to) i have started paying close attention to this thread, i am putting together a truck i bought in pieces so i will have the same issues i'm sure, lucky for me i have another one i can copy from

MAKG · Aug 21, 2007

Just wire brush the bolt hole boss and the cable end, and connect it whereever. It doesn't matter; the engine block is one piece of cast iron. Any unused bolt hole on the engine block is fine. Use the one that's easiest to get at. There is often more than one available.

SuperRob · Aug 21, 2007

Ok guys...so here it goes.

I fixed this infernal ground strap problem:

-The main strap to the engine is now connected properly (I took the 'extra' one that should never have been there in the first place out). Also that 'extra' ground strap wasnt even tightened to the block...but yet the damn thing ran forever and a day.

-Then I was able to get that orange wire connected to where 'I dont think it originally was but everyone including me seems to think it belongs' (also known as the only suitable bolt on the back of the head)

-The ground strap from the drivers side head is connected properly to the wiper motor grounding mount.

The timing light that I had rented was had an intermittent fault in it. I hooked to to a running car and it didnt flash at all, yet when I rough timed the distributor it flashed fine. This leads me to believe that I had spark all along.....

YET the damn truck doesnt run. I've double and triple checked everything.

I borrowed a compression tester from a buddy of mine, and I'm going to go check that shortly.

My last thoughts are that it may not be getting enough fuel....BUT I can confirm that theres fuel pressure in the fuel rail.....Is there a way to check that its getting fuel thru the injectors? Keep in mind that I dont have fancy things for measuring injector pulse and that sort.

I SHOULD be able to smell it when I'm compression testing though eh....

Further ideas? Always welcome.

Cheers

RobbieD · Aug 21, 2007

Gawd, this thing's being tough. Just to eliminate this one possibilty, check the two wiring grounding bolts in the passenger kick panel, one above and one below the engine computer. Then I guess it's starting with basics- got spark? got fuel? got milk? Good luck, man!

SuperRob · Aug 21, 2007

Compression test came back not too bad.
#1-120 #4-105
#2-125 #5-120
#3-125 #6-125

overall theyre a pretty decent spread....little concerned about that 105 but it could be something as little as a valve not sealing correctly.....I'm not worried enough to take anything apart again.

Tomorrow I'll have another go with retiming it from scratch, and I'll also check those ECU grounding bolts.

Appreciate the help guys!

I'll beat this damn thing yet!

SuperRob · Aug 22, 2007

Hey MAKG....

So remember how you said to rough time the distributor, with the timing lite, and turn the distributor till it flashed, and that should be good enough to get it started? Well I was talking to another guy and he said the same thing.

NOW theres the thing, I got the truck sorta running...I mean it coughed and wheezed more than anything, but the point that I got it to fire at was WAY counterclockwise of where the spark occurred at.

WTF? I dont get it! I have the SPOUT removed. everything is as it should be, wires are all double checked int eh right spots....man oh man. Anyway then I thought what I'd do was clock the rotor (distributor shaft) to the next position clockwise. This would effectively be the same as turning the distributor counterclockwise, and therefor give me more room for adjustment. Didnt work. Back to putting the rotor to where it was and hoping I have enough room to adjust the timing there....

This is very likely confusing. I'm sorry.

But it DID run, and thats the important thing!

MAKG · Aug 22, 2007

The point of rough timing is just to get it started and idled.

You run into the same problem with points -- it doens't fire in the same position if you rotate it "backwards." The difference is the "dwell." With the SPOUT plug out, it's going to be really, really retarded, so you aren't going to cause damage.

Rotating the distributor one position might work with points, but it doesn't on this engine. If you look closely at the stator, you'll notice that one of the slots is a different size from the other five. This tells injector bank #1 when to fire. So on this distributor, #1 really has to be #1. You can't shift them all.

SuperRob · Aug 22, 2007

Cool!

Back to the truck I go then, to redo it the right way.

At least I KNOW that it will run now.

Thanks

SuperRob · Aug 22, 2007

Ok boys and gals! Guess what. Now I decide when it starts...and I decide when it stops.

This problem appears to be licked! Now I just have to put the exhaust back together, the rad hoses and all, and then time it....but we are running, and we are running smooth!

Thanks to all for your help! I learned a LOT!

RobbieD · Aug 22, 2007

Congratulations!

Now, run the hell out of it.

kunar · Aug 24, 2007

SuperRob said:
Ok boys and gals! Guess what. Now I decide when it starts...and I decide when it stops.

This problem appears to be licked! Now I just have to put the exhaust back together, the rad hoses and all, and then time it....but we are running, and we are running smooth!

Thanks to all for your help! I learned a LOT!

congrats, i hope you are ready to help me with mine, i will be (trying) to start it this weekend...

Ignition Problem-o (2.9L Owners Unite!)

New Member

Forum Staff Member

New Member

Logan Andrew Feb 17, 2012

Forum Staff Member

New Member

New Member

2.9l Mafia

New Member

New Member

New Member

New Member

New Member

2.9l Mafia

Forum Staff Member

Sponsored Ad

Sponsored Ad

Today's birthdays

Member & Vendor Upgrades

Truck of The Month

Recently Featured

Follow TRS On Instagram

TRS Events

25th Anniversary Sponsors

Check Out The TRS Store

Sponsored Ad

Sponsored Ad

Sponsored Ad

Amazon Deals