rough idle after freeway driving

Hi,

Lately my van has been hard to start in the morning, (its slightly colder than normal but not that cold here in Los Angeles low 50s) and then after driving for 10 miles or so at high freeway speeds I notice that the van idles real rough/almost stalls when I come to a stop. By the time I get to the next stop light or rev the engine a few times the problem seems to go away. Once the van is warmed up I don't have trouble starting it the rest of the day, its just that initial start in the morning. I also dont notice the low idle when driving around town, its just after the longer distances at constant high rpm.

1989 townace 2c-t There are only 84k kilometers (53k miles) on the van. I'm thinking maybe dirty injectors? I was reading on some other diesel truck forums about dirty injectors and similar symptoms. Any thoughts on where to start? It feels like a fuel issue, pressing the gas down on start up gets it to start and revving it clears the low idle. seems starved for fuel. Is there more than one fuel filter on these vans? The only one I know about is the big water-separater filter with the priming pump on top.

reply to my own thread :)

So I've been digging into this more. I still have a rough time starting on cold mornings and my RPMs dip pretty hard after freeway driving in the morning. After the van is FULLY warmed up, engine running nice and hot, then it runs pretty well. Sounds smooth, idles smooth, and no rpm dipping/rough idle.

I've also noticed that I produce a healthy amount of smoke if I give it full throttle before the engine is really hot. I can only see it at night in the headlights of the cars behind me so I cant tell what color it is. I revved the van pretty hard in the parking lot with a friend watching the tailpipe. He said a little bit of black smoke but nothing crazy. I think its more under load and when the engine is cool.

So far I've checked off the following:

-went hunting for egr valve, guess the manual diesel van does not have one.

-air filter was pretty clogged, replaced it (this helped but didn't solve the rough start or rpms dropping when cold)

-PCV tube is not clogged (kinda oily but its flowing)



Currently I'm thinking I have a bad glow plug? Maybe 1 of 4 not working is enough to make it hard to start but runs ok when its warmed up. I'm going to check the plugs tomorrow. I'm crossing my fingers this is the issue. Otherwise I think I need a shop to check fuel pressure, compression, other stuff I don't have the tools for.

Thought I'd share in case you're new to diesel mechanics like I am.

Found 1 bad glow plug and another with fairly high resistance. I'm guessing it's on its way out. Hopefully i found my problem.

Replaced all 4 glowplugs and its starting and running like a champion. No more idle drop after freeway driving. No more smoke, no more rich smell.

For anyone who hasnt done this, it was fairly annoying to get a wrench on the back glow plug. Had to remove a few things to get to it. The metal pipe that goes from the turbo to the intake manifold was not friendly.

Any time your starting your van in the cold it wise to prime your glowplugs so they can warm up for a smoother start. Is there a green or yellow glowplug light in the dash? My TownAce is a gas 3Y motor so I don't know where the glowplug light would be located.

I've driven diesel trucks for over 20 years and on cold freezing mornings the engine doesn't fire up as quick and smooth as on warm mornings. It just takes about 50-60 seconds longer but it's well worth it and your van will be happier too.

Here's 3 videos of starting 3 different diesel trucks that were parked outside in below freezing temperature. In the first 2 videos I primed the plugs and both trucks fired up right away and I gave them gas after they started.
1) turn the key to on position
2) watch for the "wait to start" light to go away and count to 5 and turn off
3) repeat step 2 and turn off
4) repeat step 2 and turn off
5) repeat step 2 and start and give some gas once started and let it idle.

Maybe you don't need to repeat step 2 so many times but I usually do just so I don't smoke everyone out. This is the method the diesel mechanic told me to use and it's worked every time.

My diesel truck had 240,000 miles on it and they only replaced the glow plugs once at 170k-180k miles. But then again that's when it got a full rebuild and new front suspension. I babied that truck!! I got a new truck but that truck is still in the fleet.


The big mistake tends to be not warming up the plugs and giving it gas when it sounds like it's about to turn over... sometimes it works and sometimes it floods outs and you have to wait three times the amount of time to let the fuel settle and try again not to mention the horrid amount of diesel fumes and smoke that occurs during the wrong starting practice as displayed in the 3rd video.

Check out these 3 videos again this was suggested starting technique by my diesel mechanic and it's worked for me every time.

Hope it helps enjoy!!:thmbup:

https://youtu.be/o3xmocUFpk8 truck 1

https://youtu.be/6-eKjRSFo6E truck 2

https://youtu.be/yKuZnndLWak truck 3

Very helpful. I always wait for the glow plug light to go off but I've never tried repeating the glowplug warm up step. I'll try that tomorrow morning when it's cold again.

Replacing the 2 bad glow plugs made a huge difference buy it still sometimes wants to give me a little grief in the morning.

I still notice that i get a little bit of a tendency to stall after immediate freeway driving in the morning. After it warms up it idles super steady. It's not nearly as pronounced after the glow plug replacement but sometimes still happens. I'm starting to wonder if it's a fuel system problem? It didn't start happening till i replaced the fuel filter. Maybe it's not the right one? Or it would like another brand better that flows slightly more?

Thanks for the reply though. Super helpful

Which fuel filter are you using, I looked in the parts number thread and there's a Fram one listed and one by Wix. I think the OEM part number is 23303-64010 for chassis CR30.

I'm not sure if the fuel filter is the issue?

FRAM PS4922 Fuel and Water Separator

I just left work and it was hard to start so instead of giving it gas i warmed the glow plugs 2 more times and it started on half a crank. I think that was the trick.

When i got home it was idling low so i quickly opened the hood and pumped the fuel filter primer pump that sits on top of the fuel filter. It seemed to correct the idle? Could have been coincidence though. Im wondering if I'm getting air in the line or something. I don't see any leaking though.

Glowplug lamp hijack alert.
Mine no longer illuminates. How likely is it just the dash lamp?
what does having the ignition on with the engine off do, AKA the kid had the radio on?
I now wait a few seconds once the keys on and usually here a click (relay?)
Zero issues starting.

I've been waiting till i hear the click and had better success starting. My light works but i seem to have a much better time If i wait for that click long after the light turns off.

So mine has been harder to start again compared to after i replaced all my glow plugs. Im wondering if something isn't right with the glow plug timer, maybe a bad relay or something and I'm burning out the glow plugs. I have to take it apart and test them again to check my theory.

Ive read there is a second relay in the passenger door? I took a quick look by pulling off a panel but only saw the seatbelt. Is it behind that? I can see wiring going into that pillar if i look under the hood but can't see where Yui access that relay.

I want to test the plugs again and if they are bad walk through the whole system with a meter.

Mine is gas whit same problem never even heard of a glow sticks or that glow thing you guys were talking about. Does the gas ones have that just trying to write down all possibilities. thanks.

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Originally Posted by dogger562

Mine is gas whit same problem never even heard of a glow sticks or that glow thing you guys were talking about. Does the gas ones have that just trying to write down all possibilities. thanks.

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dogger562,

my friend your in the diesel section, the glow plugs won't apply to your gas/petrol operated van. You may already have but as a courtesy reminder use the search feature in the top right corner and use key words like "rough idle" "idle adjustment" and so forth and see what comes up, you'll need to read thru some of the threads and see which one applies to your situation.

Good luck!!:thmbup:

JDM

Orale!, yeah that's what I did, I skimmed through the thread's and found this one thanks dough I'll keep searching.