hard starts when cold... + other issues

[ren0]

Been searching through a lot of the hard starts when cold threads. Lots of good information. I commend this forum for ease of finding stuff. I haven't delved too much into it, but here are my symptoms:

Hard start when cold, sometimes when warm.
A few times the car won't stay idling past ~5minutes... just dies, followed by hard start afterward.
When I do get it to start I almost have to prime the engine (think like carbureted engine). I press the gas down to half throttle then it turns over.
Occasionally when shifting into 2nd gear the car dies. If I pop the clutch it starts back up and goes. The RPMs do not drop immediately.
Shifting through gears and RPM increases my check engine light comes on for roughly 5 seconds then goes away.

The only items I've investigated are the ICV; it's clean and seems to operate normally, replaced the fuel filter, and checked power to the fuel pump. All ok.


Any ideas on what could be causing these items or if they are at all linked? Next steps I'm thinking are relays, right?

Thanks,

[jlevie]

The first think I'd want to check for would be intake leaks. And for that I'd have a smoke test run on the intake.

[Morrison]

If the intake leak test checks out, the next item I would check is the injectors themselves. You can pull them out, then clean them at home one at a time. Connect a 1 foot piece of fuel line to a single injector with a hose clamp, fill hose with carb cleaner, then take an air compressor with a blow gun fitting and clamp it to the other end of the hose. Set the regulator to 35-40 psi and pressurize the tube while using a home-made battery pack of about 4 regular C cell batteries to momentarily open the valve by tapping the wires on the terminals of the injectors. Repeat as many times as you feed necessary for each injector.

This will also allow you to see if them are leaking when you pressurize the hose but haven't applied voltage to the terminals as well as observe the spray pattern.

If you don't feel like going through all that or have a bigger budget to work with then I'd probably look at something like this: http://cgi.ebay.com/ebaymotors/Bosch...#ht_1547wt_940

Those would drop right in without any special tuning and would giver better drivability than the stockers ever could.

Also, install a fuel pressure gauge inline with your supply line just before it reaches the rail to verify proper pressure and that it holds pressure after turning off the car. Often times the one-way check valve in the pump fails and lets the pressure bleed off too quickly after shutting down and can result in vapor lock. Cheap solution is to add the retro-fit $7 from dealer add-on check valve near the pump. Part number is: 16 14 9 068 988

If you can give the intake and fuel systems a clean bill of health, then check compression , mass-air flow sensor, the blue-top coolant temp sensor, and the throttle position sensor.

Oh, also take off the cap and rotor and check for excessive wear as well as check over plug wires and plugs. Check resistances on coil....should be .50 ohms primary and 5k ohms secondary.

[Sagaris]

Have a continuity tester or test light?

Check the idle switch for continuity with the car off.

the idle switch is inside the throttle position switch #2

http://i181.photobucket.com/albums/x60/shaheenem/ThrottleSwitchM40.jpg

There are 3 pins. The pin on the left side (closest to front of the car) is for idle, the center pin is ground, and the pin on the right side (closest to driver) is for full throttle.

Connect the test leads to the left pin (idle) and center pin (ground). You should have continuity (an electrical connection) with the throttle at idle position. You can move the throttle with your hand to from idle to part throttle and see if the switch works intermittently. I had a bad full throttle switch that only worked about every 5 out of 6 times. I checked it because my full throttle performance was inconsistent. I checked it with my continuity tester and had continuity but I discovered that opening and closing the throttle revealed that every 5th or 6th engagement of the switch would yield no continuity. I also had another E30 with a mis-adjusted throttle switch which would have a hard start and occasionally stall. The point being: The switch can work when you test it, but it might not work 100% of the time. While you are at it, check the full throttle switch as well, check for continuity on the center pin (ground) and right pin ( full throttle) with the throttle held wide open.

An idle switch that is bad or out of adjustment will cause hard starting and bad idle, since the idle fuel and timing maps that help start the car and keep it alive are not being looked up by the ECU. This is a very easy item to check and sounds just like what is wrong. Let us know what you find.

[ren0]

The first think I'd want to check for would be intake leaks. And for that I'd have a smoke test run on the intake.

Yeah I read a lot of the other threads and this seemed to be a common recommendation. I think you're the one that most commonly replied to all of them with great info too. It's on the agenda after my complete tuneup and valve adjustment.

If you don't feel like going through all that or have a bigger budget to work with then I'd probably look at something like this: http://cgi.ebay.com/ebaymotors/Bosch...#ht_1547wt_940

Those would drop right in without any special tuning and would giver better drivability than the stockers ever could.

I do have a bit of leeway in my budget. I was looking at doing this further down the line with 17# injectors and a D'sylva chip. Thanks for the tip.

Oh, also take off the cap and rotor and check for excessive wear as well as check over plug wires and plugs. Check resistances on coil....should be .50 ohms primary and 5k ohms secondary.

Have a fresh cap, plugs, and rotor, waiting on wires and the ignition coil right now (should be Friday). Everything on this car seems to be stock as it has cosmoline all over it, even overspray on the wires. I figure at 157,000 miles it's long overdue.

Wouldn't be surprised if there are some crap champion plugs in there instead of oem, though.

Have a continuity tester or test light?

Check the idle switch for continuity with the car off.

the idle switch is inside the throttle position switch #2
http://i181.photobucket.com/albums/x...eSwitchM40.jpg

I'll definitely be checking this on Friday when I complete the tuneup.


Want to commend this community. Great answers and ease of finding stuff is awesome. I came from a Toyota Supra (I LOVE straight-6 engines) community and it was nothing but flaming for the simplest of questions and half the time search results would just net those same flame threads each time.

[ren0]

Reviving this from the dead in case someone else has similar issues:

After a complete tuneup (including replacing the throttle position switch and fuel related relays) the car ran great for about a week then same stuff happened.

It would be so hit and miss I couldn't figure it out, then one day it just stopped starting at all. I let it sit a few days and tried to start her up and got going for around 5 seconds then dead. I didn't really have much time in August to do anything so she sat, and I did this every few days.

So last week I rechecked the voltage and it was getting power to the pump so no wiring issue. Went back and retested the fuel pump with a smack of the wrench to the top of it and it was able to start up for a little longer this time. Bought a new fuel pump, 20 minute install and it started right up afterward.


The most obvious part (and what I should have tried at first) was listening for the pump to prime. I had never heard it before in an e30 so I didn't know what to listen for or how loud it would be. (Loud as fuck in my GMC Sonoma) But with the new one in and the seat/hatch off I could definitely hear it running and there wasn't anything before.

So all in all, ended up being the fuel pump. I appreciate everyone's replies in trying to fix this problem.

TL;DR: The ol' smack test.