cabot

So, I though that this was a cold start issue, but I'm beginning to think otherwise. It's started fine in 30 deg F weather this year. It's 50 deg F out right now and won't start. When the problem began, I was able to get it started with starting fluid. It seemed to run and start fine around town all day. It sat for up to several hours, but never 8+. I drove about 200mi on the interstate including several starts and stops and a fill up. I also noticed that I developed a new, loud, exhaust leak from the manifold area during this trip. I have no other exhaust leaks but was unable to find it while I was stopped at a gas station.

The next morning, the starting problem was back, and it wouldn't start and run, even on starting fluid. If it leave it sitting for 20 or 30 minutes, it will crank first try, idle and then die after about 5 seconds or if I give it gas. I pulled one plug wire and have a super strong spark there. I have no check engine light, but if I jumper the diagnostic connector, I get the 3-Flash Code for no ignitor signal.

I tested the fuel pressure at the cold start injector per the FSM. It is in spec. I ohmed out the terminals at the AFM, the Circuit Opening Relay, and the Cold Start Switch. They are all in spec. When I got to the EFI temp sender, I got just over 3ohms. Initially I read the chart on page FI-68 of the 1985 FSM wrong and thought that the temp sensor was out of spec. On further evaluation. It seems good too.

I picked one up anyway while I was returning the fuel pressure test kit.

It looks like my next steps are testing the air valve per the procedure on FI-58, the solenoid resistor testing procedure on page FI-66. If it's neither one of those, I guess I need to check the resistance at my fuel injectors and the voltages at the ECU?

cabot

Heating it with a huge propane heater gets it running. Either something dried out, or it is the EFI Temp Sensor. I suppose that I'll replace it tomorrow and report back.

rokblok

iTrader: (1)

Is this coolant temp sensor you're referring to? I'm not overly familiar with the RE's.

cabot

There are 6 or 7 temperature switches and sensors. The one in question is the one on the front below the thermostat housing, to the right of the cold start injector time switch. It has a green harness connector and varies resistance to relay coolant temperature to the ECU.

rokblok

iTrader: (1)

I wouldn't thnk that would prevent starting though. If it fails it would just cause the ECU to richer or lean the mixture right? Or put it into an open loop if the resistance is WAY out of range. That's my thought line anyway.

cabot

That's pretty much what I thought. I've been reading cold start problem threads, and it seems like anything in the efi electrical system can make it mysteriously not run though. Any ideas what it could be other than a temperature sensor, given that heating the truck with a propane heater gets it running.

rokblok

iTrader: (1)

Igniter coming apart internally when cold and contracted? Or coil windings? But you said it had good spark, but you also said it threw an igniter code.

I'm stumped...

toyquad

since you mentioned a new exhuast leak, is your muffler or cat plugged?

a vehicle will not run if the exhuast is plugged enough......

cabot

Muffler and cat are both pretty new. Found the exhaust leak. The rear, bottom manifold bolt is missing. It must have vibrated loose and then completely out as the exhaust leak got louder and louder on the drive here.

Also checked the circuit opening relay and main relay. Both are within spec.

rokblok

iTrader: (1)

When did you go to Macon? Permanent?

In regards to exhaust leak, I don't think that would cause a No Start. Maybe funky O2 readings.

toyquad

yes vehicles will run with exhuast leaks, but they will not run with a plugged exhuast. when the exhuast plugs it creates excessive back pressure, which can cause "new" exhuast leaks.


but that doesnt seem to be the problem if it was just a missing bolt.

cabot

I moved to Macon temporarily when my lease ran out in Atlanta. I had a friend who owns a house and let me move in for a while without having to sign a year lease. I'm starting a new job in Griffin sometime in the next couple of months.

I also just ordered Marlin high steer stuff... Not that any of this post has to do with this thread. Haha.

Terrys87

iTrader: (1)

Looks like you covered alot of the bases under the hood. I feel you now have good spark so I am leaning to the fuel issue side. Are you using a Denso or NGK plugs? Those are about the best you can use. How is the overall condition of you tuneup? How is your fuel pressure?

Here is a link I have that I used for a non firing fuel injectors.>>> #664 https://www.yotatech.com/forums/f199...9/index27.html

cabot

Replaced the temp sender. Definitely not that.

Thanks, Terry. I'm going to check that out what you're talking about there. I have 34psi at the fuel rail. I pulled the connector on the #1 injector and found that I have 2ohms across the injector, which is within spec. Upon cranking with no jumper on the fuel pump test connector, I initially have about .3volts for about 2 seconds and then 0 volts at the harness plug. When it hits and runs for a few seconds, I also have 0volts here. This leads me to believe that it's only running of the cold start injector during these few seconds.

I suppose that I need to head out into the harness from there to find the problem? Or should I go to the ECU now and see if I have voltage at the appropriate connector there? I don't have a lot of experience troubleshooting circuits.

cabot

Well, I started pulling the harness apart. I found a lot of water and corrosion. I don't have the right color or gauge or any heat shrink here. I'll need to grab those tomorrow. Also, I started trimming and stripping the wire going to injector #1 it's corroded inside the sheathing all the way to the harness plug for the injector.

Does anyone know if these connectors are available from the dealership? I hopefully also have the option of pulling them off an engine at a junk yard around here.

rokblok

iTrader: (1)

I would get all that corrosion cleaned up before I started in on ECU. It's gotta be fixed even if it turns out to be a problem further upstream...

cabot

I'm going to get on that corrosion situation tomorrow. I'm going to pick up the three colors of wire that I need, some heat shrink and some solder. I don't have any of that here. I'm also going to try to grab a few injector pigtails out of the junkyard.

While I'm in the harness over here, I also want to figure out what this seafoam green with red stripe wire that comes out from under the upper intake is. I can't see what it's connected to on the other end, and I don't even know how this color shows up on the FSM wiring diagram. It's been disconnected since I got the truck. That means that is should be unrelated to this problem, but I have no idea. Here's a picture:

Terrys87

iTrader: (1)

From my experience, I have never had to change an ECU. It would be the very last part that I would suspect unless you suspect it being soaked with water. It is really a rock solid part in my opinion.

The water that gets into your harness does cause alot of corrsion and I have been surprised at how much does actually get into there. A hard problem I had was when the fuel injector connection would PASS a resistance check but still wouldnt start. The little crimp connectors were corrodeded and then I cut them out then soldered and shrink wrapped them. They are covered by electrical tape from the factory and is a poor design.

The seafoam wire that you are talking about and if I am looking at the right wire comes out of the harness and is next to the white double barrel plug. It is about 3 inches long and goes to a round plug. I am not sure what the round plug goes to as this is out of my 85 and it is butchered up. My 85 was used as a parts truck and is missing alot of parts. I did go and look at my 86 and it is quite similar and that green wired plug connects to the plug that mates up to that connector and it is in the harness that runs to the transmission.

If I am looking at the wire that you are showing and if my vision is correct, the wire coming out of the plug in the transmission wiring harness is red. It is to dark for a picture of it right now but I can get a picture of it later if I am looking at the same wire that you are talking about. Here is the seafoam wire with the plug I am talking about.

Terrys87

iTrader: (1)

In your picture, is that wire coming out of the same white plug harness that I am showing? It is hard to tell from the view I am seeing.

Another possible thing I may be seeing in your picture is that may be the ground connection that is grounded to the intake manifold. I cant see the end of the white wires but think it is your grounds. #4 and you may have it grounded but just not showing in the pic.

crawler85

I have an 85 manual 22re and that green/red wire is hanging, not connected to anything.

I have not been able to find out where it is supposed to go.

My truck runs good except for a hesitation at around 2500 rpm that I am still troubleshooting.