testing fuel pumps/relay

[dystynkt]

DME swap time. Post up in our regional forums. http://www.r3vlimited.com/board/forumdisplay.php?f=152 Someone should be close enough to you to lend a dme. Also if there is any shops around town, they can be a help sometimes.

DME took care of it. Thanks for the assistance!

[Philo]

DME swap time. Post up in our regional forums. http://www.r3vlimited.com/board/forumdisplay.php?f=152 Someone should be close enough to you to lend a dme. Also if there is any shops around town, they can be a help sometimes.

[dystynkt]

Ok so forget that last post it somewhat worked. Once I popped in the new main relay the car started up just fine and ran fine. Drove it around the block and it was going good. Car got 20 or so mins from my house on the freeway and just died. Same issue now it cranks but wont start. It definitely isn't the main relay because I had another extra I popped in and it didn't help. Pleeeeease help the car is now stranded and I need to figure out what the heck is wrong with it. fuel pump issue possibly? the pressure at the rail checked out fine the other day though.

[dystynkt]

Replacing the main relay fixed the problem. Thanks for all the help!!

[mojorising]

I had a problem similar to this one where I had serious trouble starting the car and it was clearly a fuel issue (spark was fine, MAF sensor fine etc). After pumping the hell out of the gas pedal for like 30 seconds it would barely start but once it started it would idle ok. I thought at first that it was fuel pump relay as in every other car I have driven the fuel pump kicks on and pressurizes the system after you turn on the ignition. Turns out this isn't how it works. I finally replaced the fuel filter and completely removed the fuel pulse absorber and it seemed to start fine after that. I spliced in a fuel pressure gauge and it read fine, fuel press reg was working great at about 45psi. Of course most of this was with a blown head gasket so who knows what kind of problems that was causing as well. Anyway, the real test will be when I get it back together to see if it will start up. Let us know when you get it figured out.

[jlevie]

Those relays just clip into the mount. Prior work on the car can result in something other than the factory positions, so you have to go by wire colors to know which is which. The order, from production, would be main relay closest to the bumper, then fuel, and closest to the firewall is O2 heater relay on an M20B25.

[Hallen]

I don't want to sound like an idiot, but just want to make sure I have this right. on the drivers side of the engine bay there are three relays under a cover. The center one is the fuel pump relay, the one furthest to the back is the main relay (which I should replace) correct? Thanks again for all your help everyone!

The one closest the the rear of the engine bay is the main relay. It's always good to confirm.

[dystynkt]

I don't want to sound like an idiot, but just want to make sure I have this right. on the drivers side of the engine bay there are three relays under a cover. The center one is the fuel pump relay, the one furthest to the back is the main relay (which I should replace) correct? Thanks again for all your help everyone!

[dystynkt]

GO find a relay intended for foglights: look for 2 terminals marked "87", but none marked "87a"...in other words, a SPST relay that has 2 NO contacts...and REPLACE YOUR MAIN RELAY!

I have had 3 or 4 cars lately do the EXACT same thing you are describing. Main relay each time, and it is the only relay configured like that on the entire car, so no swapping allowed.

GL!
Luke

Good to hear and will do. I actually just went out to the car right now and it started fine after a week of not starting. I will order a main relay tomorrow morning. Thanks!!!

[StereoInstaller1]

GO find a relay intended for foglights: look for 2 terminals marked "87", but none marked "87a"...in other words, a SPST relay that has 2 NO contacts...and REPLACE YOUR MAIN RELAY!

I have had 3 or 4 cars lately do the EXACT same thing you are describing. Main relay each time, and it is the only relay configured like that on the entire car, so no swapping allowed.

GL!
Luke

[dystynkt]

I have never experienced it doing the highway thing. So it might not be the CPS (crank positioning sensor). I would swap with a known good DME and see if the problem goes away. Take one from a friends car or something. lol

Unfortunately I don't have any friends with an e30! I'll have to post in the cali section to see if anyone around would mind helping.

[Philo]

I have never experienced it doing the highway thing. So it might not be the CPS (crank positioning sensor). I would swap with a known good DME and see if the problem goes away. Take one from a friends car or something. lol

[dystynkt]

Just thinking about this, in the last couple of weeks of this starting issue, it seemed like if I let the car sit for a bit then it would start. Like if I key in the 'on' position for a few minutes and then tried to start it then it would start right up. Sometimes it would take trying to crank it 10 times for it to start. Would the CPS being bad explain that as well? Also about the engine just dying while going 70mph on the freeway? Thanks again for your help.

[dystynkt]

I'm thinking CPS. It could intermittently be going bad, not giving a reading for the pump to send fuel.

Mine did a similar thing on start up. The sensor would not read for a bit, then all of a sudden it would kick on.

When you are talking about the CPS are you referring to the camshaft positioning sensor? If so, I have already replaced that once not too long ago but I guess it could go bad again. I haven't picked up a fuel pressure gauge yet to test that, but I am pretty sure the fuel pressure will check out ok just based on the visual test of popping off the line and watching the pressure of the fuel flowing to the engine.

[jlevie]

Ok great thanks jlevie. I will pick up a pressure gauge to test the pressure. Just to understand, when should I get pressure? Will it be while the engine is cranking trying to start? Just want to make sure I am looking at the right time. Good learning experience.

Check the pressure while cranking the engine, or with the fuel relay jumpered.