M42club.com - Home of the BMW E30/E36 318i/iS

DISCUSSION => Engine + Driveline => Topic started by: brianw84 on May 12, 2009, 08:01:32 PM

Title: engine will turn over but not start
Post by: brianw84 on May 12, 2009, 08:01:32 PM
It seems like its not getting fuel, would i be correct in thinking i need a new fuel pump? Or could it be something simple like the fuel filter
?
Title: engine will turn over but not start
Post by: Sophia69IS on May 13, 2009, 04:04:34 PM
That's probably the best guess. See if any fuel is getting to the fuel rail. Actually, do you hear the fuel pump turn on when you turn the ignition in the on position? Because I know when I do I can hear the fuel pump turn on.
Title: engine will turn over but not start
Post by: fazerfreak on May 13, 2009, 05:22:22 PM
check the cps? (crank sensor) should be around 600ohm´s +/- 50 i think, gasspump wont start if its broken.
Title: engine will turn over but not start
Post by: DesktopDave on May 13, 2009, 09:19:41 PM
Yup - likely the CPS.  I gave mine a good cleaning and the car started right up.  I also patched up a few cracked vacuum hoses.

You should do the stomp test first - if you're not getting a check engine light (and it's not burned out) it might also be that little fusible link off the battery buried in the trunk.  It's in the smaller positive wire, wrapped in shrink tube.
Title: engine will turn over but not start
Post by: brianw84 on May 13, 2009, 09:59:34 PM
thanks ill be cleaning the cps in the am. I got the car started, dont know why, but when i had the front up on jackstands it started, and is running now. Although it take significantly longer to get the engine started now. It also sounds like its backfiring now whenever I lift off the gas.
Title: engine will turn over but not start
Post by: DesktopDave on May 14, 2009, 07:15:56 AM
Glad to hear it!  Check for vacuum leaks, especially under the throttle body.  If unmetered air is getting in, it'd be difficult to start.  If it's running rich, I'd test the O2 sensor or the fuel pressure regulator.  Make sure that little vacuum hose coming off the regulator is in good shape.  If that's cracked it makes for all sorts of unpredictable symptoms.
Title: engine will turn over but not start
Post by: brianw84 on May 14, 2009, 10:33:50 AM
The hoses are old, cracked and need to be replaced. Ill be doing that next week. Good to hear that may cure my current problem.
Title: engine will turn over but not start
Post by: brianw84 on June 16, 2009, 12:24:15 PM
the car isnt starting again, it just cranks and cranks. ive installed a new fuel pump, filter, and cps sensor and still nothing. ideas? Ive switched the relays around to try to rule that out and no difference.
Title: engine will turn over but not start
Post by: Blip Bavarian on June 16, 2009, 12:47:50 PM
Does your CEL work?
Title: engine will turn over but not start
Post by: DesktopDave on June 16, 2009, 01:00:21 PM
Sounds like it's running too rich.  Get that meter and the Bentley out and test all the likely culprits for proper readings.  Make sure you don't have vacuum leaks, and check the little battery wire fusible link for continuity.

Do you get a check engine light?
Title: engine will turn over but not start
Post by: brianw84 on June 16, 2009, 01:53:33 PM
the check engine light has been on forever because the o2 sensor is bad. that never caused the car to not start before.
Title: engine will turn over but not start
Post by: DesktopDave on June 16, 2009, 04:28:17 PM
Bad O2 sensor will make the car run rich but shouldn't keep it from running.  Do you know what the stomp test is?  Turn the car key to position 2 (don't start the car though), then press the gas pedal to the floor five times in less than five seconds?

If you're handy with a soldering gun you can swap that expensive O2 sensor for a cheap four-wire Bosch from a Ford Mustang.  They're functionally the same.  Fuel injectors too...all that's in here somewhere too.  Search for '19# injectors'

It'll make the computer blink a code out on the CEL.  Just search 'stomp test' here and you'll get all the info you need.
Title: engine will turn over but not start
Post by: brianw84 on June 16, 2009, 05:33:04 PM
i should have mentioned stomp test says no faults.  im running out of ideas.
Title: engine will turn over but not start
Post by: B318M42W on June 17, 2009, 12:01:18 AM
spark / air / fuel... is AFM good? are the plugs fireing? getting fuel on the plugs??? start with basics.
Title: engine will turn over but not start
Post by: DesktopDave on June 17, 2009, 09:02:36 AM
I know you already replaced the CPS...I'd just pull the plug and test to see if pins 1&2 have the magic 680 ohms +- 10%.  I'd also test the throttle position sensor.

You're getting a CEL, so the DME, main relay and fusible link are most likely OK.

I'd also try to jump the fuel pump relay...eliminate that as a cause.  Pull the relay and put a paper clip or short bit of wire between terminals 30 & 87.  Pull either of the fuel lines and see if it's pumping gasoline...then reconnect the fuel line and see if that starts the car.

If that won't do it I'd try testing the fuel pressure...a bad FPR or pump will keep the engine from starting too.
Title: engine will turn over but not start
Post by: brianw84 on June 18, 2009, 02:46:16 PM
i jumped terminals 30&87 which caused the pump to turn on but the car still would not turn on, i bought a cheap replacement relay at advanced auto which didnt fix it.both  lines from the pump have gas in them, the line pointing to the drivers side  didnt seem to be pressurized with fuel like the other one though.
Title: engine will turn over but not start
Post by: brianw84 on June 18, 2009, 07:25:03 PM
heres the whole story if it helps, my father borrowed the car for one day while his was in the shop to go to work, which is at least 100 miles round trip. the vacuum hose on the intake came off and instead of opening hood and fixing it, he just kept his foot on the gas the whole time and drove it home. been broke since.
Title: engine will turn over but not start
Post by: beemer1 on June 18, 2009, 08:23:58 PM
Yeah replace the vacuum and coolant hoses.  It makes a world of a difference once everything is buttoned up.

I would recommend reading "the mess under the intake" thread because you can eliminate a bunch of hoses/problems.  Much more reliable and a heck of alot of easier to install everything once you have it apart.
Title: engine will turn over but not start
Post by: DesktopDave on June 18, 2009, 09:04:16 PM
+1 on that...it might not cure the problem but replacing those hoses will eliminate them as a possibility.  Bosch FI systems really work well if they're tight.

Which hose came off?  The one to the fuel pressure regulator?  The FPR sends fuel it doesn't need back to the tank, so you might not see much pressure in that return hose.  As long as gas is going in & out you're OK.

Get a meter and ohm out that crank position sensor.  I can give you detailed directions if you need them or don't know what I'm talking about.  The computer WILL NOT send power to the fuel pump relay if it gets no signal from the CPS, and it won't set a code either.  My CPS failed when it was a bit oily, BTW.  Should be about 700 ohms on pins 1&2.

The fuel pump is most likely good...the fuel lines go in & out.  The relay is probably good too.  You can test it by jumping 12v through terminals 85 & 86.  If it clicks it's likely OK.  Carry a spare too.
Title: engine will turn over but not start
Post by: ApocolypseAutoEngineering on June 21, 2009, 01:21:26 AM
I just overcame this problem. Check the connector to the fuel pump it may be calcified. I just cut it off and made my own makeshift connector with two crush connectors. My car sat for 3 months until i stumbled upon it. To test it, make the jump at the relay end and start fiddling with the connector, pulling it pushing and moving it around. If you hear the pump kick on in fiddling there's your problem.
Title: engine will turn over but not start
Post by: brianw84 on June 30, 2009, 07:32:50 AM
turned out the i got a dud cps so i replaced it and she started right up. been idling a lil rough and low at times. and throttle response seems sluggish, but maybe i just got used to the cars i was driving while it wasnt running.
Thanks for all the help guys
Title: engine will turn over but not start
Post by: DesktopDave on June 30, 2009, 08:35:55 AM
Glad to hear it.  What exactly was wrong with the CPS?  Was it bent, dead or just no signal to the DME?

Clean the ICV too...they're another weak spot.  Mine's sluggish too...it's an M42 after all...

Pull the plugs, ohm out the wires & coils too.
Title: engine will turn over but not start
Post by: brianw84 on July 03, 2009, 01:41:17 PM
the cps wasnt givin any signal so i sent it back for a new one. i cleaned the icv, havent ohmd the wires and coils yet. its been idling around 500 when i start it up and will go to the normal 800ish after a bit. sometimes will cut out a few seconds after start up.  It most def also needs new hoses which ill be doing soon along with cleaning everything
Title: engine will turn over but not start
Post by: DesktopDave on July 03, 2009, 01:42:53 PM
Sweet.  Enjoy the ride.  Aren't those CPS a PITA?
Title: engine will turn over but not start
Post by: brianw84 on July 07, 2009, 04:28:41 PM
well i was enjoying the drive, until my car started dying, the engine would lose speed, the thottle wouldnt do anything, you could floor it and nothing would happen,  it would just slowly die. if i blipped the throttle alot i could get it above 3000 and it would run. it sounded really rough like it wasnt firing correctly. stomp test gave me 1234 which is :
1234 Vehicle Speed Sensor (Speedometer A Signal) This code is stored when no plausible speed signal is detected while driving. The requirements are an engine speed >2500 rpm and under load for more than 10 seconds. Check the speedometer function and the wire to the DME . Also check for codes in the Combi Unit (Instrument Cluster).

the spedometer seemed to be displaying the correct speed, (a few mph off as always) so im not sure what im looking for. any ideas?
Title: engine will turn over but not start
Post by: DesktopDave on July 07, 2009, 05:18:57 PM
Speedometer pulls a signal off the differential.  Doesn't sound right.  Is the tach normal too?

I had a similar problem with the MAF, it wouldn't pull over an idle.  But your problem sounds different.  I hate to say this but it sounds like the CPS might still be the culprit.  What's the air gap from the crank toothed wheel to the CPS?
Title: engine will turn over but not start
Post by: brianw84 on July 07, 2009, 06:57:14 PM
if i have to change the cps one more time......ill measure it and get back to you tommorow.  i should be able to take my skid plate off blindfolded by now.

the tach seemed normal apart from nothing happening when i stepped on the gas.
when this was happening the engine sounded like a v8 dragster idling all rough, and a few misfire/backfire. it happened when going slightly downhill, and then hitting a long uphill. i dont know if the angle of the car would have anything to do with it.
Title: engine will turn over but not start
Post by: DesktopDave on July 07, 2009, 09:34:05 PM
I left that plastic shield off mine.  Just gets in the way.  I'm not sure what'd cause a misfire like that.  Did you check the throttle position sensor?  Maybe that's how the DME determines load?  Check the TPS before you crawl under the car...
Title: engine will turn over but not start
Post by: brianw84 on September 02, 2009, 06:41:37 PM
so i finally had the time to put a new TPS in tonite and the problem seems to be cured, but the idle is still crap and it will cut out. I need new hoses and im guessing i need to clean the ICV. Thanks for the help !
Title: engine will turn over but not start
Post by: brianw84 on September 03, 2009, 12:04:13 PM
Nevermind on the sensor fixing the problem. the car idles a little bit better for a min, then idles like crap shaking the entire car, when i push the gas it doesnt always result in the engine doing anything. Its backfiring ALOT. and turning off, usually right after i back out and take my foot off the gas. more ideas?!
Title: engine will turn over but not start
Post by: B318M42W on September 03, 2009, 04:37:01 PM
check your plug wire order... disconnect neg. battery cable overnight (clears the DME)
might sound like you have toooooo much fuel? not burning it all and then burns in the exhaust.
Title: engine will turn over but not start
Post by: AcSchnitzer318is on September 04, 2009, 12:09:08 AM
Have you pulled the plugs to see if you have fouled them?  If it was running rich for an extended period of time, that is a definitely possibility.  

If you have not replaced all the vacuum lines, intake mani gasket, and cleaned the ICV.  Do that next.
Title: engine will turn over but not start
Post by: brianw84 on September 09, 2009, 06:16:44 PM
The problem is now partially fixed. I cleaned up the mess of hoses (that contained many leaks) and simplified them,  cleaned my injectors, cleaned everything, replaced the gaskets and put in new plugs. the idle is now fine, and throttle response is much better, but a few times the engine wouldnt do what the pedal was doin and would slow down and sputter, then suddenly speed ahead. anymore ideas?
Title: engine will turn over but not start
Post by: B318M42W on September 10, 2009, 08:15:09 AM
maf, tps, ecu
Title: engine will turn over but not start
Post by: brianw84 on September 11, 2009, 02:41:48 PM
im getting code 1216 - Designates error with potentiometer in Throttle Position sensor. Some later model cars have potentiometer, as opposed to switch (TPS) found on majority of e30 s. This code will be active if inappropriate sensor values are read by control unit, and although presence of this fault code may indicate bad potentiometer, wire harness connection at the sensor is common issue (corroded, loose connection, or broken).

I replaced the tps last week...any more ideas? how would i know if thats the problem or if it might be the maf or ecu?
Title: engine will turn over but not start
Post by: brianw84 on September 14, 2009, 07:04:23 PM
I fixed it! It turned out that the hose goin from the icv was collapsing once it warmed up. i replaced it with a much thicker one and its running perfectly now!
Title: engine will turn over but not start
Post by: She loved E on September 18, 2009, 06:32:10 PM
I have the same problem you had. I ordered all the "mess under intake" parts today; I'm also going to check the hose to the ICV to see if its collapsing. Wish me luck!
Title: engine will turn over but not start
Post by: brianw84 on September 21, 2009, 03:38:24 PM
Yes cleaning up the mess of hoses does wonders for idling, ive noticed throttle response is better too. I used AC hose to replace the collapsing hose, probably overkill, but its what i had. just remember to clean EVERYTHING while your in there. Esp the ICV.