I need advice!

isocyn8 · isocyn8's Garage

Hey guys, I am hoping to pick some of your brains. I have been reading a lot of posts, but still unable to find the problem. I have a 87 944na that will not start. It didn't have spark, chased it down to the reference and speed sensors. I replaced them and the car now has spark. I had replaced the dme relay before the sensors. The dme is one of the cheepo ebay ones. Anyway, the fuel pump is not running and I have very little fuel in the fuel rail. I jumped the fuel pump over at the dme relay and the pump started up and seems to do fine. I put the dme relay back in and still no sound from the fuel pump. I am wondering now if the injectors are firing. I am wondering if I need to get an oem dme relay, or if my problem is somewhere else.

zedsn · 02-05-2010, 05:09 PM

Hi, there is a way to bypass the DME relay and put a jumper wire on it and then the fuel pump will run. Look at the past threads and there should be instuctions on this or look in clarks Garage for some help. You might want to get a fuel pressure gauge and mount it at the end of the fuel rail to make sure that you are indeed getting the proper pressure.

carlege · 02-05-2010, 05:10 PM

looks like you have already determined that its the relay. The car should start with the jump inplace

krystar · 02-05-2010, 05:12 PM

so wait....if u jump the fuel pump, does the car start?

it could just be a bad relay

isocyn8 · isocyn8's Garage

Nope with the relay jumped it still wont start........

jamesjedi · 02-05-2010, 05:33 PM

How long has car been sitting?

krystar · 02-05-2010, 05:47 PM

when the fuel pump jumped, verify that u do have pressure at the rail.

most likely u have two issues contributing to the same symptom of no-start

isocyn8 · isocyn8's Garage

The car has been sitting about a two years. I am waiting on a fuel rail adapter to throw on a pressure gauge. What u got in mind krystar?

krystar · 02-05-2010, 05:57 PM

2 years = bad gas. good call james.

isocyn8 · isocyn8's Garage

I drained the fuel and put in fresh gas before trying to start the car. I also changed fuel filter.

jamesjedi · 02-05-2010, 06:18 PM

I went through something similar. The fuel pumps on these cars fail after sitting a long time. If you can test the pump - as in make sure that you hear it from the back of the car you will know that it is working. You do not know if it has enough pressure. But, you will know that it is working.
I would try to find out if your injectors are firing. That is where I found my problem. I had only one injector firing. I am not comfortable recommending that you pull them, and then have someone turn the ignition - THAT is DANGEROUS. I would take your injectors to get tested and cleaned. They are more than likely in need of it regardless of them working or not. Remember that injectors and fuel rail work disassembly will mean that gas will spill/spray due to pressurization. Please be careful of any ignition source.
After my injectors were cleaned the car started immediately.

Clarks-garage.com is a very good reference.

krystar · 02-05-2010, 09:42 PM

nooooo u def don't want to be cranking with the fuel rail off. it should be relatively easy to tell if the injectors are firing though.

unplug the coil power wire (little black and little green wires). turn the ignition for a couple of seconds. then take out all 4 plugs, they should all be wet.

minho78 · minho78's Garage

OK, you said 87S. Disconnect the O2 sensor(Attached to fuel pump harness, maybe causing a short). Also check fuse 35 if it's OK.

jamesjedi · 02-06-2010, 04:53 AM

I am saying that it is dangerous to crank the engine while your injectors are out of the cylinder head, although it will tell you if they are firing. You should take them out and get them cleaned and tested.

drew1 · 02-06-2010, 01:39 PM

Make sure that strainer in the tank isn't skined over after sitting a couple of years

isocyn8 · isocyn8's Garage

The fuel pump when it is jumped at the relay pumps fine. It is getting good pressure and flow. It just wont pulse the injectors. I tried a friends dme that is supposed to be good, but getting the same result. I also purchased a third dme relay just in case. haha. So, with the dme relay in place fuel pump wont run, but I have spark. If bypassed at the dme relay the fuel pump runs, I have spark, but no injector pulse. I verified this with a noid light. All fuses checked. Fresh gas. different ignition switch, however not new. One thing is that I found when putting the ignition switch on is that an aftermarket alarm was hooked up at the ignition switch. I removed the alarm, and connected the wires back to their respective partners. Not really sure where to go from here..............Looking for a link to check power at the dme connectors so I can verify I am getting what I need. Any Ideas would be appreciated. Thanks guys.

jamesjedi · 02-07-2010, 05:49 PM

I am thinking that if you have fuel pressure and spark, you have an injector problem. Do any of the injectors fire?

isocyn8 · isocyn8's Garage

Nope, none of the injectors are pulsing. The fuel pump only runs if the dme is jumped though.

carlege · 02-07-2010, 06:59 PM

ok so you need a DME Relay and new injectors. That seems to be a starting point.

jamesjedi · 02-07-2010, 07:07 PM

Check to see if you have volatge to the injectors. Perform the following to check for fuel injector supply voltage:

- Disconnect on fuel injector plug.
- Turn the ignition switch to the ON position.
- Check for approximately 12 VDC on the injector plug terminals. There will be 12 VDC on one plug terminal and 0 VDC on the other terminal.

The above is from Clarks garage.

It is part of the fun.