Rod Underwood

Ok, the 87 5-speed that was intermittently stopping will now not start at all. I've swapped out the LH, no luck, I've jumpered the puel pump, seems to be running.

One time before when it would not start, the alarm seemed to be the problem. It started after I had gotten out and locked and unlocked the doors with the key. I've searched and can't find a definitive location for the alarm connector "Z"?, (at the fuse panel, I believe from what I've read)a picture would help, so that I can jump it and see if that's the problem.

Thanks
Rod

WallyP

The "Z" bypass is for the early cars - the S4 is different. On your '87, put a jumper from the black/red wire on B23 to the yellow wire on F25. If you put a toggle switch on the jumper, you will have a manual kill switch. If you want to do it behind the Central Electric Panel, hook a wire from the 15 bus (power only when the ignition switch is on) to Terminal 86 in the socket for Relay XVI, the EZK relay. The wiring is shown on Page 97-273 in the manual.

borland

If the CE panel jumper that Wally suggests eliminates a problem with the factory alarm system .....

you said you swapped out the LH, I assume you mean the LH controller. Besides the Fuel Pump relay, have you swapped out the LH relay? An old LH relay can be problematic with symptoms of intermittant start or no start because it handles a high current load.

Rod Underwood

Yep, switched out that relay with a "thought to be good" relay, I have some more new relays on the way and will replace when they arrive.

Wally,

jumpered the alarm and it still wouldn't start. I pulled the cap of the passenger side fuel rail to see if it was pumping fuel. Turned is over a couple of times and no fuel, although some fuel ran out when I took the cap off. I guess I need a new fuel pump or have I missed something?
Thanks
Rod

borland

You said the pump runs with it jumpered. The fuel pump relay gets power directly from the battery. Fuse is between the fuel pump relay and two fuel pumps.

So, if you pull the fuel pump relay and jumper the contacts in the CE panel's relay socket (pins 30 and 87), you should hear the pump run. That assumes the CE panel fuse for the fuel pump is good. If no pump noise, must be fuse. With relay jumpered, check for 12V at the fuel pump terminals at the rear of the car.

WallyP

You need to clearly determine whether the fuel pump delivers fuel with the fuel pump relay jumpered. Be VERY careful - you will hopefully be pumping a vigorous flow of fuel. Use a hose or catch bottle to avoid spraying fuel all over everything!

If you get fuel flow with the jumper, replace the fuel pump relay with the horn relay or defrost relay. If that cures the problem, install a new fuel pump relay. If no fuel flow with the jumper, check the fuse, then check both fuel pumps.

If you get fuel flow with the jumper, but still get no fuel flow with a known-good fuel pump relay, check the LH and EZK relays by direct substitution of known-good relays or jumpers and repeat the checks for fuel flow.

Let us know what you find.

Rod Underwood

Thanks, I did take the end off the fuel rail and no fuel when I cranked it.. I have some new 253B's coming, so I'll trade those out. I might as well order a new fuel pump as well, it's not as though I'm not going to evenutally need it, but it kind of looks like that's the problem right now.

I can't find any bad fuses anywhere. The pump hums when jumpered, but it could still be bad and not actually pumping.

Thanks, I'll post what eventually fixes it.

Rod

borland

The pump has a DC motor, so if its humming, it has both 12V and a turning shaft. Before ordering the pump, run the flow test Wally suggested.

If your fuel pressure regulator is working properly, a pressure gage at the fuel rail will tell you if the pump is capable of maintaining regulated system pressure. This test is documented in the WSM. There is also a pump flow rate test procedure there too.

Rod Underwood

I should have said I can hear the pump humming, I'm not convinced it's running. As I indicated, I removed the cap on the end of the fuel rail and cranked the engine. That should have pumped fuel, or maybe I'm missing something? I can put a pressure gage on it and see if that makes a difference, but if no fuel is coming out, it seems to me that the pump is not pumping.

I'm frustrated and probalby not seeing something obvious, maybe tomorrow will bring a better day. ;-)

Rod

borland

This should be a process of elimination. You need to have a running engine for the pressure gage test.

If your fuel pump relay is not activated during starter cranking, then you won't have any fuel pumped. You need see if you have fuel flow with the fuel pump relay jumpered. That will take those parts out of the equation; then work from there. There are still other reasons for your problem that you haven't explored.

Rod Underwood

Ok, the "new" fuel pump will run if jumped and key on, but not when I crank with the key. Cranks good and hard. I switched out all of the relays with new, replaced the EKZ relay with one from a running car. Switched out the EZK and LH computers. Jumped the alarm - connected the black w/ red strip three down on left side of panel B to the top right yellow of panel F and no dice.

I pulled the cap off the fuel rail and it had pressure, so I assume the pump is pumping gas when jumped.

Someone mentioned a bad ignition switch. I guess that's what I try next. Anyone got a good one lying around - out of a car - that I could try. If all else fails, I can pull one out of one of the running cars, and try it.

Suggestions are welcome. I know I may be an idiot, so you can skip that one.

Thanks
Rod

borland

EZK and LH controllers get electrical power from terminal 15 bus (ignition) as well as direct from the batter battery.

You should check for ignition power coming from 15 bus power with the ignition switch turned on. There are several places that can act as test points for ignition switched power, such as ignition coils, or CE connector W pin 15. Would help if you had a schematic. If this checks good, you probably have a bad speed sender.

Since you don't have a diagnostic sensor or o-scope, the next place to check would be the Speed and Reference Mark Sender (Crank Position Sensor). It's located under the air filter housing at the back of the engine. You could swap this out since you can't test it.

Rod Underwood

Thanks, at least now I have a couple of other checks - power to coil with switch on, and swap out crank position sensor -... I'll try these tomorrow, I'm done for tonight..

Rod Underwood

Ok, time allows me to try this again.

The fuel pump pumps if jumped, holding at 35psi 20 minutes after jumping.
The car will not start with the fuel pump jumped.
The injectors are not firing.
I jumped the alarm system as indicated B 23 to F 25 and it made no difference.
I switched out the EZK relay with a known good one from a running car.

Still no injectors.
Verified that the plugs are firing.

I've double checked all fuses and all relays.

Any suggestions?

Thanks in advance
Rod

dr bob

For grins, remove/disassemble/clean/reassemble the slammer red wire connections at the battery positive terminal. One of the three is for FP/injection/oxy sensor heater power. Two others are for front cooling fans.