random turning off

[kassim503]

Well heres a new problem, I was driving and my car just turned off, it has no warning signals liek coughing or anything, it just turns off like sombody turned the key off. Also the fuel pump, injectors and ignition wont fire sometimes, you have to turn the key off and on several times to get it going. Could this be caused by a faulty throttle position sensor? I broke both bolts off that was holding the unit up and I had it tied down with wire ties. I Jb welded it to the right spot and ill take it for a test drive now and see if its better. Anybody got any insight on this? I think its because I drove the car through mud and then I washed out the engine bay afterwards. Oh and I have a gasser.

Also does anybody know if body shops can fix body lines on cars? My Infiniti G20 got rear ended today and the body lines arent really that straight and the trunk gaps arent right anymore.

[kassim503]

Correction, the fuel pump runs, but only for a second or less, the ignition works, and the injectors dont fire. I am positive its a bad connection or a ECU problem, leaning more on the bad connection side because I did get everything wet when I washed it. Also the throttle position sensor could be my problem, but i doubt it, I tested it to the FSM's specs and it was pretty much ok. Anybody with insight on this? I need to drive tommorow and right now the car dosent really get me too far without stalling.

[kassim503]

On page EF&Ec-26 in the 1983 fsm, at the bottom it says that the ignition switch is directly wired to the fuel pump relay and the efi relay, is this true?


Also on the next page, ef+ec27 it shows two fusible links, i am familiar with this one, but i have no clue as to where is this one, the pencil below shows it, its a box that says fusible link, and it has a green, brown and black wires in it, followed by the white. Check out the pic below, I need to know where this connector is

[Carimbo]

you have to turn the key off and on several times to get it going.

This description almost makes it appear to be a failing ignition switch. The electrical switch portion of it, not the keylock part.

You can use a re-bent paperclip to jumper the terminals on the back of the connector that plugs into the ign. switch. This will help you isolate to see if the switch is the problem or not. I used this method to find the cause of a sudden engine electrical cutout problem in my diesel. See Stranded! Engine Stopped Dead, No "Ignition"--- I'm sure you've seen it before.

[asavage]

On page EF&Ec-26 in the 1983 fsm, at the bottom it says that the ignition switch is directly wired to the fuel pump relay and the efi relay, is this true?

I think so. The diagram looks reasonable. Ign switch powers the EFI relay's coil (fusible link supplies power to contacts and on to the ECM), but the fuel pump juice comes from the Ign switch too; the fuel pump relay's coil is powered by the ECM.

Odd but true.

Also on the next page, ef+ec27 it shows two fusible links, i am familiar with this one, but i have no clue as to where is this one, the pencil below shows it, its a box that says fusible link, and it has a green, brown and black wires in it, followed by the white. Check out the pic below, I need to know where this connector is

Your pic is nearly unreadable, but you supplied the FSM page number, so I can see it.

On the diesels (which have the same three fusible links, it appears), they (all three) are under a plastic rectangular cover, suspended on a bracket between the rear of the battery and the strut tower. Here's a pic of the three fusible links with the cover off, and with it tilted to one side. The relays panel is also upside down, can't help that.

(click on image for larger)


You may also be getting hit with the "broken splice in harness" problem that Carimbo & I have had on our rigs. Read up on it here. Your symptom may be the beginning of that splice's total breakdown. Just a guess. You can easily figure that one out by putting a voltmeter on the B/W wire on either the EFI relay or FP relay (same wire, same color code). Tap that wire, run a long lead into the car (or up on the cowl), connect to voltmeter, put VM where you can watch it (duct tape to windshield is one of my choices), and when you the car dies, key ON, watch voltage. Voltage less than 10v? Check upstream (at Ign switch or whereever). Good voltage there, car dead? Break in harness/splice.

Looking again at EF/EC-27, Ign switch terminal 2 (B/W wire), see how it has four harness splices? One of those may be your culprit. Use the voltmeter, it'll lie to you but it'll also tell you true.

Remoter guess: looks like the FP relay ground also has a harness splice. After the above VM check, if it checks OK (for power to relays but engine dead), move VM positive lead to FP relay B (black?) wire. Should have zero volts, if anything above .2v you have a relay ground problem.

HTH

[asavage]

This description almost makes it appear to be a failing ignition switch. The electrical switch portion of it, not the keylock part.

Kassim, I have two used, and one NOS (from eBay) Ign switch. I'd send you one of the used ones as a loaner to test for just the shipping charge, but I still vote with using a voltmeter first, it's the fastest way to condemn or indemnify a switch of any kind. I don't like just swapping parts for this kind of problem. But if you want one, I'll send you one.

[kassim503]

I jumped the fuel pump relay with a piece of wire and the car works fine. There is a intermittient signal going to the fuel pump relay, car seems to run fine, but ill see I have to drive it 200 some change miles today so she better not develop some other problem. Anybody know any breaks in the wiring that could give power to the fuel injection relay but not give power to the fuel pump relay? Ill probably check tonight but if I can get a lead on this itll be great

[asavage]

I jumped the fuel pump relay with a piece of wire . . .

Do you mean that you jumped across the contacts, or ran power to the relay's coil, or ran a separate hot feed to the output contact?

There is a intermittient signal going to the fuel pump relay

See, "signal" implies that the ECU didn't supply coil voltage. Is that what you jumpered?

I can't look at the wiring diagram right now, I'm supposed to be working. Later.

[kassim503]

I jumped across the contacts, but that dosent seem like my real problem because the car did fail several times on my trip. Also I made a mistake when testing before-I forgot to turn the key in the on position and i assumed i wasnt getting the coil power, it gets power all the time. So i narrowed it down to 3 things, really its almost the same three since i started, a broken splice somewhere, a faulty relay, or the 7 pin connector has gone bad.

Also i need help locating the splices on the wire harness, if i remember there are only three splices that need to be looked at, scanned it and pic below, they are circled in red, they are on page ef& ec-27 in the 83 fsm. I dont know the location of these splices, so does anybody know their general location? I dont want to butcher up the harness


Also there was a splice problem that Al encountered, with that white wire being corroded at the splice, with that problem the starter wont spin right? My cars starter works fine, I just dont get any gas, also is this problem associated with diesel models only, or does this splice exist on gassers as well?


Forgot the pic below, but here it is now, click for larger
[img=http://img91.imageshack.us/img91/5503/u ... ym2.th.jpg]

[kassim503]

Looking again at EF/EC-27, Ign switch terminal 2 (B/W wire), see how it has four harness splices? One of those may be your culprit. Use the voltmeter, it'll lie to you but it'll also tell you true.

HTH

Whats the best way i could check these splices with a VM? Ohmeter with clamps on the test leads? Are visual inspections sufficent for this kind of stuff?

[kassim503]

Ok, well it seems like I may have found the problem, mabye. Well theres a good chance its either one of these, it could be the 7 pin connector, its the one next to the lower radiator hose, or it could be the relay itself. Well when the car does have its problem the EFI would only turn on for about a second, and each time it does this itll turn on and off for the same length of time, until I get it started. I pulled apart the 7 pin connector and there was a small amount of corrosion on 2 of the female plugs, and one of them was connected to the EFI relay, could be a problem point. Also after the car stalled I unplugged the connector and pulgged it back in and it started and ran (for a lengthy half minute).

A thing that makes me think its the relay is that jumping the relay connections with a piece of wire so that the EFI is on all the time seems to make it run for a longer time. Also the relay seems to click on then click off if its hot, like if i apply power to the coil and the relay is underhood temperature it seems to click on and then off right away (didnt check with ohmeter yet).

well I guess ill just start digging into it 2mm, if the connector isnt at fault I think ill chop open the wire harness and check the connections.

Also I "lost" a relay, after the car stalled at a intersection, i proceeded to waive people around my car and then I went over to jump the connection and if i remember correctly the relay dropped to the floor and i forgot to pick it up. Also the relay was new

[kassim503]

Some progress made!
The 7 pin connector had a little bit of corrosion and dirt in it, cleaned it up, restaked the prongs and coupled it back together, I also noticed the rubber band that goes around the plug was loose and probably had no sealing capability whatsoever (deal with that later). Ran the car, still stalled occasionally, but after a few minutes the car ran great for the rest of the time, no problems at all, NONE! I let it idle on the driveway for about a hour, came back and it was still going. Let it cool down and started it back up, still ran. Then I drove it around and it didnt stall either, mabye its fixed, mabye its not because after I cleaned the connection it still stalled, ill keep the car around the house for the next day or two and keep it near home in case the trouble resurfaces.

[kassim503]

I take that back, I am almsot where i started again.

Right now i am just interested in getting the car going, even if it just means jumping the contacts on the EFI relay, even though i am positive that power is getting to the relay coil just fine. So after jumping the connection the only other link on the EFI relay system is the 7 pin connector, which is located on page ef&ec27, right in the middle, left of the distributor. There are no other splices or problems and I am left with no clue as to what to do, ill check the EFI 35 pin harness connector but im pretty sure that is not my concern right now.

Should i just cut off the 7 pin connector and install another kind of connector in its place? Should would it be smarter to just Solder all 7 wires together, its not like im going to be pulling harnesses out anytime soon Is it possible that the wiring itself could be bad, like what I hear happens to flood vehicles?


Mabye ill go clean out that single specific prong on the 7 pin connector one more time before it gets dark out, hopefully that would bring some results

[kassim503]

reliability seemed to increase a little bit after cleaning out the 7 pin connector again. Now the car only stalls about half the amount it used to do, so its a improvement. Whats the chances of ECU's frying? I never seen a broken one, but i believe this could happen often. Also the car seems to stall right when u need it, like idling at intersections, or when you are traveling through areas without a breakdown lane.

[kassim503]

power is getting to the ecu, I think there may be a ecu problem or a grounding problem for the ecu. Whats the chances that the ecu would go bad? How can i test this? Is there any way to check if power is getting to the injectors without frying anything? Also in addition to all these nice problems that my car is encountering, the cold start valve dosent fire any more.