Won't start. No spark. A little help please!

Terryxj · 07-12-2008, 03:00 PM

Hey guys. My 1991 325 ix won't start. Well, let me explain that. Yesterday it wouldn't start, so I left it and let it sit for 20 minutes, came back and messed around with the ICV some and it started, so I thought it was the ICV. Started fine all day. Went out later last night and when leaving downtown it wouldn't start again. Fooled around with it for 10 minutes or so (again, messing with the ICV and various hoses on top) and it started. It had been sitting for about a year before I bought it. When I test drove it (and up til now) it started fine. My first thought was bad fuel and maybe the fuel pump went bad. I checked it, and I'm getting fuel. I then checked the plugs to see if I was getting spark. Unless I'm doing this wrong, I don't see a spark. Replaced the dist. cap and rotor because they were pitted and had carbon trails. Still no spark. I'm thinking ignition coil. Does anyone know what the resisitance should be from the center pin on the coil to one of the outside pins. I can't find a tech article on this anywhere. My reading when set to 20k is 5.82. Is this normal. If this is normal, where should I look next? Also, is it normal for the ICV to buzz if the ignition is in the on position. Could the ICV be the problem still?

Terryxj · 07-13-2008, 11:01 AM

I messed around with the ICV and MAF sensor this morning and it started. I'm starting to think it's not the coil anymore. When you cold start the car should the ICV buzz and move to the closed position. It buzzes as long as I have the key in the on position. Also, after I got it running, if I hit the gas to rev it the car wanted to die, it only wanted to idle nothing more. Does this sound like MAF sensor to you guys?

Terryxj · 07-13-2008, 11:52 AM

I have now found out that my fuel pump is not engaging when I try to start the car. This may have been my problem all along, but sometimes the car starts fine. I have ~12 volts of power to the pump when cranking, but no noise or vibration from the pump. Is it common, when a pump is going bad, for it to work intermittently?

Terryxj · 07-13-2008, 01:39 PM

OK, now the fuel pump is working again. Car starts, but idle is rough and when I try to rev it, it cuts out. Check engine light is on, and when I run the code it's 1215, mass air flow sensor. What in the heck is going on with this car? What could cause the fuel pump to work intermittently like that? Any ideas?

Jeron · Jeron's Garage

The pump comes on, gets up to pressure, then shuts off until the car is started.

Rough running could be the MAF or an intake leak. It could also be many other things but I would start there since you have a MAF code. Check for cracks in the intake tube.

Terryxj · 07-14-2008, 02:02 PM

OK, multiple problems. The MAF is bad, new one on order. Also, fuel pump relay is bad. This is why the fuel pump was working off and on. Replaced relay, and now idles fine. Can't wait for the MAF to get here and see that everything is good! Thanks Jeron for your help, I can' believe no one suggested relay though! Guess they figured I'd obviously checked that already

Glad it's an easy fix! I was scared it was DME or Fuel Pump or something a little more costly. Thanks again.

Jeron · Jeron's Garage

I usually suggest bypassing the relay by directly powering the pump, but you had more than one problem and you mentioned it was providing 12v while starting and that it would idle.

Glad you got it fixed.

Terryxj · 07-15-2008, 06:06 PM

OK, so evidently it wasn't the relay. Tried to start it this morning and same old stuff. I'm going to check again tomorrow night to make sure I get power at the fuel pump everytime I try to start. If this is the case do you think it's the fuel pump. Will a fuel pump work intermittently? I just thought when they were gone they were gone. A mechanic friend suggested it may be a bad ground somewhere. What do you think?

Jeron · Jeron's Garage

I know how it is, but you have a lot of scattered info in your posts.

When trying to start you need to verify power to the pump, spark and fuel pressure would be nice.

One thing to keep in mind is the crank sensor which will cause a "no start". However crank sensors dont usually fail intermittently.

Terryxj · 07-16-2008, 04:19 PM

I agree, my posts are a bit scattered. That's because I had no idea where to begin. Thanks for bearing with me. I think I have figured out the fuel problem. It's electrical and I have remedied it for now. I know I don't have a spark problem too, so that helps. I have a different problem now, so I think I'm going to start a new thread since the title to this one is a little misleading now.

martinflewell · 07-20-2008, 07:30 PM

I had a similar phantom intermitant no-spark problem with an '87 that sat for a year prior to my purchase. I went through fuel pressure, new ECU, ICV etc. It turned out to be the crank sensor (Thanks Jeron for the help on the diagnosis back then). Not sure what it was about sitting around for a year and the crank sensor but it's worth checking in my opinion. It would crank and crank but only start intermitantly. No difference between hot and cold starts etc. Just random.

Terryxj · 07-23-2008, 12:13 PM

Yep, that was it. So evidently if this thing is not operating correctly you get no spark and your fuel pump will not come on. Thanks everyone for your help. Now, when I start it cold it idles rough. Any ideas on this?