Cold start, Lots of smoke

kiff · Post by **kiff** » Tue Mar 25, 2008 8:35 pm

I have a 84 diesel rabbit. When I start it up cold it smokes like a SOB and runs like crap. Once it warms up, she runs awesome, no smoke unless I gas it from a standstill.

The other issue is a major lack of power. I know these engines only have 58hp, but dont have have almost 80ft/lbs? any hill when on the freeway I must downshift to 4th, if not 3rd to keep up my speed.

any help would be awesome.

Pu241 · Post by **Pu241** » Tue Mar 25, 2008 8:54 pm

I just went through the same senario with my '81!
I suspect your injectors.
You don't say how many miles on this unit, but seems general concensous is the injectors are good for 60-100K miles.
Swapped mine for set of rebuilt and been cruising at high mach ever since.
OK, maybe not anywhere near high mach numbers. But, she runs well so much better!
Also if you decide to replace injectors get the 3.5mm fuel return line before you replace the injectors.
It saves so much pain and diesel fuel.
Uh, someone I know didn't, and wasted a lot of fuel and could have potentially destroyed his coolant hoses as well as his timing belt.

Post by **Fatmobile** » Wed Mar 26, 2008 12:19 am

I'm guessing retarded timing.
How does the cold start lever effect things?

kiff · Post by **kiff** » Mon Mar 31, 2008 8:20 pm

I just checked my injectors when the engine was warm, cracking the fuel line and each time the rpm dropped. I am now waiting for the engine to cool down to test it when it's cold.

My other question with the car has been that cold start knob. Do I use is as a choke? full on to start, half till warm, then off? the car does not want to idle as well when I don't pull it out on a cold morning, but once warm, if I pull it out, I dont get and funny running engine.

No I have been checking a few things, and I think #4cyl is low compression due to a leaking injector seal, when I put some water over the injector I get bubbles from the head and injector. I am going to try putting in new heatshields and hope that solves the issue. Can I put anything on the threads as a sealant aswell?

surfcam · Post by **surfcam** » Mon Mar 31, 2008 8:56 pm

Its a good idea to maybe put a little copper coat or something like that on the threads. The cold start knob is real a timing advance. It helps in starting. If you look under technical tips on this site you will see a procedure. Most cars will vary a little because of compression, timing and pump condition. Mine start better with it in. Then I put it out once it starts. If the cars warm or above 10C I put it out to start.

kiff · Post by **kiff** » Mon Mar 31, 2008 10:07 pm

Ok, I just went and opened the lines with the engine cold. all made the RPM drop EXCEPT #2! what does this mean?

it works when warm but not when cold?

JRM · Post by **JRM** » Mon Mar 31, 2008 10:25 pm

sounds like #2 has a bad glow plug, or the injector is not spraying correctly.

rallydiesel · Post by **rallydiesel** » Mon Mar 31, 2008 11:06 pm

You could just get new nozzles, which is much cheaper than new injectors. Glowplug in cylinder 2 may be burned out and maybe more.

kiff · Post by **kiff** » Mon Mar 31, 2008 11:23 pm

hmm, ok, I will check the glow plugs. The injectos look to have never been replaced. I don't really want to spend the $100+ for new injectors if I don't need to. I am fairly mechanicly inclined, how hard is it to rebuild a injector? am I better off to buy new ones if they are worn out? I don't have a pop tester, nor do I know of any shops in the area that could test them. Any other diagnostic tips based on my issues?

JRM · Post by **JRM** » Mon Mar 31, 2008 11:44 pm

with the injectors out, one can look in the holes and see the glow plugs glow bright red- this will most likley be your issue

I had my injectors rebuild by the local diesel shop that specializes in injectors and pumps.

Post by **Fatmobile** » Tue Apr 01, 2008 4:13 am

If you take the injectors out and get them tested you might not have to pay to get them rebuilt.... but if you do get them tested and find a bad one it will need to be replaced.
Yeah, $100 is alot of money.... you could probably rebuild them yourself for $45 then get the breaking pressure set for $50- $60.... otherwise you'd be lucky to get it done for $100.

I suppose it shoud be mentioned that a bad injector can burn a hole in the head,... doesn't happen often.

I'm not sure what it means when opening an injector warm changes nothing, but cold it points to a problem with that cylinder.

kiff · Post by **kiff** » Tue Apr 01, 2008 7:22 pm

Well my mileage is still decent (37-40mpg) when warm it runs like a champ. Maybe a fouled glowplug?

82vdub · Post by **82vdub** » Tue Apr 01, 2008 9:22 pm

kiff wrote:Well my mileage is still decent (37-40mpg) when warm it runs like a champ. Maybe a fouled glowplug?

Could be your cold start problem, but not your low power problem (if you really have one). Your low power problem may be because it only came new with 52HP. These aren't speed demons.