teamking

I'm trying to start up a project car that hasn't run in ten years.

I just installed a new fuel pump, and it seems to be working fine. I jumpered terminals 30 and 87b and got about a liter of gas in 30 seconds from the fuel rail.

However, when I put the DME relay back in place and try to start the car, it turns over but won't catch. I checked for 12v at the fuel pump and WAS NOT getting it while my wife was turning the key.

I ran through the fuel system troubleshooting on clarks-garage (http://www.clarks-garage.com/shop-manual/fuel-16.htm), and now have the DME out of the car and am inspecting it for bad solder joints. I can't see anything.

So before I order another DME, I wanted to back up and make sure there aren't other reasons.

For instance, I've disconnected the oxygen sensor, since I discovered that it was shorting and blowing the fuse to the fuel pump. No reason that the car shouldn't start up without it, right?

Also, my oil pressure sender seems to be bad. I haven't yet replaced it. Would this cause the car not to start?

When I turn the key to 'On' or 'Run', I get a big '!' in the instrument cluster, and a chime every second coming from G15 (I think) in the fuse/relay box. I had assumed this was caused by the oil pressure sender. Any thoughts on this?

Thanks in advance for any help!

quinnfiske

A DME relay is pretty cheap and it is a good idea to carry a spare anyway. The fuel pump should run when cranking. If it is not, a bad DME relay could be the cause. A cracked solder joint may be only visible under a microscope. You may want to take a small soldering iron and hit all the joints to reflow them.

The car should start with the o2 sensor unplugged. Ditto for oil pressure sensor. The ! comes on when you turn the ignition on. The chime may simply mean the door is open when the ignition is on.

jpk

Engine speed and refrence sensors could be bad. The DME won't run the fuel pump untill it sees the engine speed sensor signal.
Does the tach needle move at all while cranking?

Yabo

Im assuming you tried jumpering the DME relay..?

Try hookin gthe fuel pump up to a battery and turning the key. It would at least tell you if everything else is working.

teamking

I do not have an oscilloscope, but I did measure the resistances for both and they were within spec. The tach DOES bounce as I crank the engine.

teamking

Yeah, I was wondering about the DME relay.

The clarks-garage procedure is:
1. Check the fp fuse
2. Jumper 30 to 87b to check the fp and wiring to fp
3. Check for 12v at 30 (how could you not pass this if you passed number 2)
4. Check for 12v at 86 while key is turned to 'Run'
5. Check for 12v to DME (pins 35 and 18)
6. Check the speed sensor (didn't have oscilloscope, but resistance was ok, tach bounces during cranking)
7. Check the reference sensor ( ditto )
8. Check pin 4 to the DME for 12v when the starter is cranking
9. Replace the DME and/or repair solder joints.

So, I got through 1-8, but was left wondering if I'd proven that my DME relay was working.

Another thought was that I might have some grounding issues.

teamking

By jumpering the DME relay, do you mean pins 30 to 87b in order to test that the fp works (when told to do so)? If so, then yes, that was part of the clarks-garage procedure.


I considered hooking the fp up to an external battery, but didn't know if I'd do any harm.

Do I have this right: the fp is suppose to be running if either of the following conditions are met:
a) the starter is cranking the engine
b) the engine is running > 200 rpm

hpservertech

Anyone else have any idea's? I"m going through the exact same thing right now.

teamking

1.5 hours of soldering and I'm done with one of the two boards.

I can't believe there are people that do soldering for a living.

What do you think the chances are that this will get the car running? I'm pessimistic.

quinnfiske

Keep at it, you will get to fire eventually and it will be worth it.

hpservertech

Have you check to make sure that your getting voltage at the fuel injectors? I'm starting to think mine is related to no spark not no fuel with the exact same symptoms & results as yours.