85 BRAT no start/run issue

[TIMBERTIGER]

Not sure if the FPCU is whats keeping your car from running. I had an 84 BRAT with a bad FPCU (after taking it apart you could see a burnt spot on the circuit board) and i ended up wiring my fuel pump to the back of my alternator for power while the car was running with a pushbutton to ACC power for priming and the car ran great without even having a FPCU installed. 

[naru]

 

This evening I picked up a brand new FPCU for my '85 BRAT.  As you can tell, it doesn't look exactly the same, but the parts person who found it for me has over 17 years experience at the dealership.  The person I talk to when I picked up the part assured me if he was the one who found it for me, it's the right part.

 

Apparently, if what I was told is correct, this was also the ONLY brand new part in the entire U.S.A.  That's right.  There was only one of these in the whole country, and now I have it.

With tax, it was just shy of $190.  Ouch.  I sure hope it works.  If not, I will be totally stumped with this issue.

 

I didn't take a picture of it, but right outside the front door on display at the dealership was a very nice light metallic blue '85 BRAT.  The only wear I could see on it was where a shell had been on the bed. 

 

You are still barking up the wrong tree.

 

The FPCU is not that complicated.It merely senses primarty ignition pulses created by the ignition module and closes some fuel pump relay contacts in response.

 

A brand new FPCU is NOT GOING TO WORK withouit primary ignition pulses(flashing test light on coil negative w/cranking)

 

The only components common to the ignition and FPCU are fusible link #2 and the ignition switch.

Since you have  power at the coil,they look OK.

 

FYI,the module has 3 connections.Ground at the bottom is the 3rd.

Therefore there are 6 possible arrangements of the meter leads when using the diode test.

Use them all for comparing.

An open on the ground side = dead module

 

I only have a turbo module  to test so I cannot provide #s for yours.

 

 

Ignition needs to work in order for the FPCU to work,not the other way around.

[mhisstc]

IT RUNS!

 

Absolutely correct the new FPCU made no difference.  But, I did want to have a new one to verify functionality.

I also got *another* new distributor.

 

So what's different?

 

Absolutely nothing.

 

Every circut, wire, component, etc. tested out exactly as before.

 

I have no idea why it is running now, and why it wasn't running before.

 

Here's how it happened.  I tried the new FPCU. Nothing. I put the old one back.  I put in the new distrubutor with new ignition module.  Nothing. I was ready to tow it to the dealership, open up my credit card, and give them instructions to "make it run".  That's when my wife forced my daughter to come out and help me with her car.  I proceded to show her everything I tested and did to her car to make it run without success.  She was bummed.  As I was cleaing up, the only thing I hadn't tried was to run a wire directly from the batter to the (+) side of the coil to bypass all of the other wiring through the car. So I pulled the (+) lead off the coil and replaced it with the wire directly to the battery.  I did that and it immediately started.  So then I went back through the circuits thinking the ignition switch was at fault and maybe I hadn't tested to make sure the coil was receiving power when the strater was cranking.  I verified that.  So I still had no idea why it wasn't running. previously, but I went ahead and set the timing again as it got dark.

 

This morning I went through everything again to verify I was getting power to everything I was supposed to get power to when I was supposed to get it.  It *should* run with the (+) ignition wire attached to the coil without the jumper.  I put the (+) ignition wire back on the coil as I had done innumeral times before.  Nothing initially, then it fired after I pumped the throttle once.  

 

That's where things are now that I've put evetyting back together.  It runs great and starts with no issue.  And I have no idea what the difference is.

[jono]

Did I not suggest direct power to coil quite a while back? And you only just done it?

 

You could a left car out fro t thinking no one would or could pinch it....some punk rocks up with his hot wire none the wiser toyour woes, bust the steering lock and hhe's got a getaway car!

 

I have chased a few electrical dead ends and its my fault did not tell you Murphy was an auto elec

 

A mate says sometimes two plus two equals five

 

Years back I was just trying to get rear I dictators to work looking for a break I powered lights from socket back to switches. Could not find fault. After the reverse power up ran fine until cars end!

 

Just recently my power antennae stopped going up. I plugged my spare ant into the loom to see it worked. Plugged loom back to dead ant. Decided to work again just like that

 

Your daughter must be impressed now with all the new components and her dad.

 

Well done. Now you qualify to answer trouble shooting posts!

[mhisstc]

Yup.  Took me a while.  We'll see how long it stays running. Hopefully a long time.

[jono]

Something most of us don't do is check all the data, specs, Ohms n Volts when everything is working fine.

 

What if you went over your work now see if something is different? Other than fact its running just fine

[mhisstc]

With as much time as I've put into this vehicle over the last several months, I don't even want to look at it. And I still need to get it to a local shop to replace the front half shafts (a project that snowballed from a single torn front CV boot), the poorly constructed replacement exhaust probably needs to be completely redone, and the replacement windshield I had a body shop install is leaking and has cracked following the recent temperature fluctuations. The same shop broke the first replacement windshield trying to install it. The windshield rubber is very had to find, and any replacement chrome trim in the rubber is impossible to find. I may end up taking it to another place if they want to charge me for another windshield.

 

At least my daughter is happy being able to drive it as-is for a few days before it heads to the shop again.

 

Edited November 25, 2017 by mhisstc

[jono]

You will find new rubber seals for your screen on eBay.com.au or another is Oz rubbers or something. Oz auto moulds and rubbers. I have sent a few to UK for a bud. Fitted two myself and they are good quality and fit

[jono]

Very satisfying doing screen seal yourself. After some prep first time took me twenty minutes with slim rope cord black sticky gunk silicone spray

[mhisstc]

Thanks for the tip on the windshield rubber.  I'll keep that in mind if we have difficulty finding one.

 

Several years ago I put a new windshield and rear sliding window in a '79 Chevy pickup with a similar style rubber surround.  I was super paranoid about breaking the windshield, but I got fresh rubber and sealants from LMC Truck, looked over several tutorials, took things slowly, and it worked out great.  I was hoping that by having someone else who was supposed to be more practiced at replacing windshields than I am, the windshield in the BRAT would have been a simpler affair.  That hasn't been the case.

[DaveT]

These days, you probably need to find an old shop, restoration shop, etc. to get those kind of windshields installed by someone who knows that system.  All the modern cars, just use glue in.  Most may have never seen that kind of gasket.

 

I did one on a 78 wagon a long time ago.

 

My Dynahoe uses something similar.  I installed most of the glass in the cab.