HELP...my transplanted 3.2 won't start...

cnielsen · 07-10-2005, 06:22 PM

OK, I just completed a transplant of an '86 3.2 into my 73.5 targa. I followed all the instructions on the following link...

http://www.pelicanparts.com/MotorCity/marcesq/

Everything seems right, and checks out. Grounds are grounded and there is power where there should be power. I am getting fuel past the fuel filter so I assume it is getting where it needs to go. The engine cranks over just fine but does not fire. I checked for spark and I am not getting anything.

Any suggestions on how to trouble shoot this mess...

TIA, Chris

PCA7GGR · 07-10-2005, 06:25 PM

Starting off with the easy stuff - DME relay?

KTL · 07-10-2005, 06:47 PM

If everything checks out with Marc's instructions?

Check the connections on the motor. Particularly the connectors for the timing and reference sensors at the front, left rear of the motor. They're the two black, one white connectors near the rear of the intake manifold. If the black ones are connected to the wrong location(s), the car will crank, but won't start.

Just had the same problem on a 3.6 swap I did yesterday. Broken reference connector connector allowed us to plug it in upside down. After scratching our heads for a few hours, I decided to flip the connector over and it fired up!

Hope you find the problem.

BReyes · BReyes's Garage

I would recheck all your connections, and that the DME is good first.

Regards,

cnielsen · 07-10-2005, 10:27 PM

Thanks for the input. I actually have a complete second set of all the DME motronic stuff. So I switched out the DME relay and the brain...still nothing.

Speaking of the DME relay, there is a large red wire with a green stripe. Marc's instructions say to tape it back because it is not needed. This seems to be a big important wire. Does anyone have a schematic that might show where that wire should go?

I have not tried switching those two black connectors on the left rear of the engine...mainly because there was a glob of white paint on one of the black connectors and then a matching mark on one of the plugs...I assumed these matched up. however, I will try switching them.

Scratching my head...

Chris

IROC · IROC's Garage

Check the ref/speed sensor plugs for sure. Common mistake. I did it.

I, too, used Marc's instructions when I swapped a 3.2 into my '76 and the only thing that wasn't perfectly clear (and ended up causing me trouble) was the wiring to the fuseblock. The wire that typically goes to the alarm (black wire) needs to see 12V when the key is in crank and run (12V whenever the ignition is on won't hurt). The other black wire must be tied into a circuit that sees 12V during cranking and running (the mistake I made).

The large red wire with the green stripe is the fuel pump power, IIRC. I did not use this as I wired my fuel pump through the old CIS relay.

This is from memory two years ago, so bear that in mind. The main thing is to make sure you've got fuel pressure at the injectors (and signal) and spark (check voltage at coil as this can be messed up also).

Good luck,

Mike

cnielsen · 07-11-2005, 06:10 AM

Thanks Mike,

I have both of those black wires going to a power source on the fuse block that gives power when the key is in the "on" position.
Is that correct?

I did try switching those two black connectors on the left rear of the motor and still no go.

Does anyone have a wiring schematic for the motronic harness? Is the Bentley manual sufficient for this info?

Chris

KTL · 07-11-2005, 07:14 AM

Bentley gives decent wiring diagrams. Take a look at one to show you the way.

Like Mike said, our 78 SC with a 3.6 had a direct connect from the engine harness to the fuel pump. Did not use the body wiring. We plan to do the same with the 3.2 that's going into the SC.

Good luck!

IROC · IROC's Garage

Quote:

Originally posted by cnielsen
Thanks Mike,

I have both of those black wires going to a power source on the fuse block that gives power when the key is in the "on" position.
Is that correct?

I did try switching those two black connectors on the left rear of the motor and still no go.

Does anyone have a wiring schematic for the motronic harness? Is the Bentley manual sufficient for this info?

Chris

Well (and my disclaimer is that I haven't looked at this stuff in over 2 years)....one, and maybe both, of those black wires needs to see 12V during "cranking" and not just "run".

One supplies voltage to the coil and the other tricks the ECM into thinking that you have a correctly functioning alarm. The problem I had was that I had tied the wire that fed the 12V to my coil into a circuit that only had 12V during "run" and not "cranking", so the car would crank and crank and not start as there was no spark being produced during cranking. Sometimes, if I got lucky the coil would spark very briefly as the key returned to the "run" position from the "cranking" position and the car would start.

Anyway, something to check. I really apologize for not being certain on this stuff as I don't have any of my data with me and it's been a couple of years.

One thing to check would be to put a voltmeter on the + side of the coil and check for 12V when the key is in "run" and then have someone crank it and make sure you still have 12V there.

The Bentley manual is actually pretty good. Heck, I even used a Haynes manual to figure alot of this out.

Good luck,

Mike

cnielsen · 07-11-2005, 08:28 AM

It sounds like you might be onto something here. I put both black wires on the same fuse in the trunk. Which I think is a sunroof fuse or something. I don't have a sunroof but it did have power in the "on" position.

What fuse would have power during cranking?

IROC · IROC's Garage

Quote:

Originally posted by cnielsen
What fuse would have power during cranking?

Ahhh...the $64k question. I don't know. I had to hunt around for one. I couldn't even tell you what I ended up using.

Hope this helps....

Mike

KTL · 07-11-2005, 09:33 AM

Timmons' instructions for our 3.6 were specific about choosing the black wire that gets 12V while cranking

I'm sure that's where your problem lies. I'll check the wiring diagram in my Bentley this evening if you don't find something sooner.

cnielsen · 07-11-2005, 10:58 AM

You know this site and all it's members are truly amazing!!! To think that we may have potentially found a wierd electrical problem in 7 responses.

Thanks guys, let me know how I can find this damn wire. I will take a test light to the fuse block when I get home and look for something that lights up while cranking.

Chris

KTL · 07-11-2005, 11:08 AM

On our car, a '88 Carrera, we did just that. The harness is obviously already native to the '88, but we simply put a voltmeter on a black wire and cranked it. The one that gave ~12V while cranking is the one to which we made the connection. I'll check exactly what that black is for- gotta be coil signal like Mike said - when I get home.

cnielsen · 07-12-2005, 08:16 AM

OK, so I found the correct fuse. It is the one that runs the fuel pump...but that is not what it was labelled. I think it was the fourth one from the bottom of the top set of fuses (remember this is an early car).

IT RUNS....!!!!!!!!!!!!

Thanks a ton for helping me figure that one out.

BUT... now there is another question. It runs but it surges. Vrrrrrum, vrrrrrrum, vrrrrrrrum.... It also does not take throttle quickly. I assume there is a vaccuum leak. How do you trace those?

During the transplant I changed a few vaccuum lines to clean things up and to mate it with the early car chassis. Here are a few pics...them mostly pertain to eliminating the brake booster vaccuum line.

From this...

To this...

And blocking off the fuel charcoal canister...

Again, any input would be much appreciated!!!!

Chris

Scooter · 07-12-2005, 09:04 AM

Before you go through all your vaccuum hoses, I know this is too simple, but check your gas cap. I had the same problem one time with my 3.2 after I filled up with fuel. I just took the cap off and put it back on tight, then it ran great again.

cnielsen · 07-12-2005, 09:45 AM

Good idea Scooter but my fuel vent lines are completely bypassed on this car. However it makes me wonder about the oil cap... the carrera ones seem to be a much tighter fitting unit than the earlier steel ones. I'll try bagging it just to see.

Keep the ideas coming.

randywebb · 07-12-2005, 04:12 PM

All the money & time to do a complete engine swap, and.... it's the frickin' fuse. Just like always.

don911 · don911's Garage

I recently had a vroom vroom issue with my 3.2L while changing the AFM with a MAF. Mine turned out to be the wire connector going to the MAF/Air Meter. When I re-connected the connectorto the MAF, two of the contacts pushed out and did not make contact. You might disconnect and check to see that all 4 contacts are in place.
It is the connector shown in you last picture, just to the left of the air filter.

cnielsen · 07-12-2005, 10:54 PM

OK, I figured it out!!!

It was the booster vac line. I thought that whole thing was rediculous so I thought I would bypass it and take a line straight from the throttle body to the intake manifold...instead of the convoluted path that the old system took. Well, apparently you can't do that. A pair of vice grips on my new vac line fixed the problem. I will replace it with a proper setup later...for now...time for a test drive!!!

Big smile to follow...

Chris