Problems starting in the morning or when cold ? Adjustment

[jessef]

If your L400 (4M40 / 2.8L diesel engine) is running great when warm but sluggish and coughs/weezes when cold and starting in the morning, three things are suspect.

1. Cold start valve. The adjustment screw is located on the right-side (closest to the battery) in the image below. Use an 8mm closed-end wrench to crack loose the locking nut and then a fine flat-head screw driver to adjust clockwise/counter clockwise the cold start.

This will lower/raise the RPM when it's cold. You may have to adjust it a few times before you get it right.

I prefer to have the cold start / idle in park / idle in drive with brake one around 850 RPM. This gives a nice and smooth idle speed which you can tell by the non-shaking steering wheel.



2. Injection Pump front / main seal. This is known to wear over time sucking oil/air into the Injection Pump which causes it to start very rough in cold weather/mornings and blow lots of smoke.

The Injection Pump has to be removed from the rear and is not a simple job for a backyard mechanic. I would recommend to have one of the Delica-favorite shops do this. You will notice an immediate increase in power, clean/smoke-free starting and better mpg. A worthwhile job to do.

3: The connection from the wire bringing power to the busbar connecting all 4 glow plugs could be rusted or loose or just plain old. Cut that conection off, removed the busbar and put individual wires from each plugs going to where you cut the connection.

[delicat]

Good to know! And you forgot another good possibility... (you should know since you pointed it out to me!)

#3:
The connection from the wire bringing power to the busbar connecting all 4 glow plugs could be rusted or loose or just plain shitty. Cut that conection off, removed the busbar and put individual wires from each plugs going to where you cut the connection.

[manic29]

1. Cold start valve. The adjustment screw is located on the right-side (closest to the battery) in the image below. Use an 8mm closed-end wrench to crack loose the locking nut and then a fine flat-head screw driver to adjust clockwise/counter clockwise the cold start.

This will lower/raise the RPM when it's cold. You may have to adjust it a few times before you get it right.

Thanks for the tips!
So clockwise lowers the rpm and counterclockwise raises the rpm? Or the other way around?
Thanks!

[jessef]

I forgot which turn raises/lowers rpm's.

[ShaneA]

Hey Jesse,

Is that the valve you mentioned in another post regarding cold start up in Winter? I've noticed my van didn't idle any higher when cold than when warmed up (around 850ish), but thought you mentioned having it idle around 1100-1200 when starting up in Winter.

I think I've got a bus bar issue (or one of my glow plugs is gone). I've recently had rougher morning starts with more white smoke than usual. After about 20 seconds the idle smooths out and the smoke disappears. I'll have to take a look at it this weekend.

Shane

[jessef]

Hey Shane

If you have a voltmeter, check the voltage at each glowplug.

I've found that the main wire that goes to the busbar supplying voltage, often that connection is old and can limit the amount of current flowing through.

Also the busbar can have some corrosion on it.

My solution has been to do away with the busbar by cutting a fresh cut at the main wire and then splicing it 4-ways directly to each glow plug. This will ensure that each plug is receiving the same voltage.

If your glowplugs are all receiving voltage and work, then the main shaft seal on the injection pump is likely the culprit of your cold starts mixed with white smoke.

Left overnight, a tiny amount of air seeps in through the shaft seal and will cause the sneezing at start up and then smooth out normally after.

In the dead of winter, I use my foot as a 'cold start' usually letting it warm up a bit around 1,100 RPM and then drive away.

[Pacific JDM Parts]

Good post again Jessie.
To raise the cold idle you turn the screw anti clockwise.
You may need to adjust it a few times to get the cold start idle speed you require.

[Rural]

I'm pretty sure that my van has the injection pump seal issue. Left alone for around 12 hours it sputters for about 10 seconds on startup and belches an impressive amount of dark grey smoke. After about 10 seconds, it smooths out and stops smoking. If I turn it off at that point, it restarts beautifully.

So where would I find an injection pump seal? I'll bet Mardy is my best bet. In fact, I'll bet I can get it under warranty. But, for those people lucky enough not to be under warranty, could one get the part at a NAPA?

And this is the one negative I've ran into with my van purchase (but I'm still happy). This problem is really hard to miss and easily diagnosed. (I caught it on my second morning start.) I think it is unlikely that someone at Amazing didn't notice it. If I were in the Vancouver area, I'd just bring it back to Mardy to be fixed, but from east-central Alberta, that's a long trip. Note a huge deal, but still annoying. Again, I'm otherwise ecstatic. The van is in really good shape.

[jessef]

It could be one of the connections from the main power wire to the glow plugs.

It is possible that one of those connections worked loose after driving it for a while.

[Bullwinkle]

Rural,

*apologize for the slight hijack to talk about pump seals*

Had the same issue with my '94 when I picked it up last summer. Ran great until we started getting cold mornings in late August/September. After sitting overnight it would run really lumpy first thing in the morning and got to the point that even after warming it up for a few minutes would stall at pretty much the same place every day (going up a small hill about 500m from home) and sometimes more than once. Not sure if that matches what you're seeing in yours though.

Was pretty sure that it was the injection pump seal and did hear from Paul @ Pacific JDM Parts that he had some on hand but since the pump needs to be pulled to replace the seal, it was something that I preferred to have a pro deal with.

Since I'm on the Island, I asked the crew at CC Autos to replace it for me along with a handful of other things (coolant expansion bottle, misc. bushings, etc.) and after the repairs the change was dramatic and immediate. Right from day one it started well with no issues and a few days later (December at this point) we headed out for two weeks to Washington and Oregon. No sputters, stalls, smoke clouds at all and it felt like a totally different vehicle. An additional plus is that the fuel mileage did improve as well. Ran strong through the whole road trip and with the exception of the alt/battery going to the charging graveyard in the sky, it has been solid ever since.

Short version: I suspect that most JDM suppliers should have these seals and I can't say enough good things about Paul and Pacific JDM Parts if you wanted to have a go at doing it yourself. They have them listed on their site but since it's a pretty invasive operation my sense is a shop that has done these before is likely the better option.

Just my $0.02 and best of luck with it.

[Rural]

Agreed. I'll check the plugs and the connections to the plugs first. Simpler stuff first.

There's definitely something wrong. It is obvious. And it's not just on cold mornings. It did it to me this evening after sitting outside on a hot day for about 8 hours.

And it might just be me, but it seems like it is getting worse. I'll have another data point tomorrow morning.

It could be one of the connections from the main power wire to the glow plugs.

It is possible that one of those connections worked loose after driving it for a while.

[jessef]

Are you using additive for the sulphur in the diesel ?

[Pacific JDM Parts]

It sounds like all the classic symptoms of the fuel pump front seal leaking.
Its a shame you had to get all the way back to Alberta before you found out about this.
All 4M40 engine should have the fuel pump seal replaced when the vehicles are imported as its been a know issue worldwide for years.
The seal is available from any diesel shop.

[Rural]

Jfarsang, yes I am using an additive. Mardy sold it to me. I can't remember the name, and I'm too lazy, right this moment, but it really reminds me of castor oil.

Thanks Pacific, I'll be checking the glow plugs as its a good idea even if it's not the problem, but if they are fine, to the diesel shop I'll go.

[pajerry]

Jesse, do you have any more pics of the cold idle mechanism?

I have a small coolant leak coming from where the snap ring is facing up, so I removed the unit to get in there. Took it apart, got the snap ring out and sealed up (I hope), and now I can't get it back together since I forget which way to add tension to the spring before reassembling it.


Worse comes to worse, I know CVI has one kicking around I could take a look at. Sometimes its worth paying the pro's :)