compression results

[GregCrabb]

Hi, I finally got around to doing a compression test on my '86. I was surprised
194,000 miles

all eight cylinders were 400. Now, this was on a cold engine (if 85F is cold) sitting out in the sun all day. I just didn't feel like messing with a warm engine today. The very first cylinder I checked was driver's side front, and it read 350, then the other seven were 400 so I rechecked it, and it was 400 on the second check...all after 6 puffs with glow plugs out. How does this sound to you guys?
It starts without a hitch in the summer, but in winter, it has a hard time unless it's plugged in. Even with modified glow cycle and new plugs and new batteries.

[john8662]

Those results sound great!

Might be the plugs you have installed, and or the condition of the injectors affecting cold starts.

[GregCrabb]

Forgot to mention also new(rebuilt) IP and injectors. Plugs are 60G AC's. It starts much better now than when old injectors and IP were in...Just puzzles me. but like I said, in warmer weather it starts almost as quickly as my 01 VW does. I don't know, I'm just glad those compression numbers were good. I was considering selling or trading it because I can't drive it to work in the winter months (work nights) and there are no plug outlets in the parking garage at the hospital. Maybe I should install one of those heaters that doesn't require electricity...then I'd be covered at home and away.

[NH2112]

Does it get cold enough there that you'd absolutely need to plug it in at work? I worked at a ski area this past winter and even when the temps never got much above zero during the day mine started pretty easily after being parked for 16 hours (not plugged in.)

[IUPAC]

I had a similar experience with poor starting when cold. I changed glow plugs, controller, batteries, cables. None of which really improved starting. Then my starter took a dump without warning. The new starter made all the difference.

[GregCrabb]

I can get it started when it's on down in the 30's overnight with a little patience and cranking steadily...but into the 20's or below, it just doesn't want to start...and I live 50 miles away, so I don't want to get stuck at work. I wondered about the starter...I don't know how old it is. It looks pretty new, but that doesn't mean anything. I did some research a couple years ago about which was better, the original 6.2 type starter or the newer 6.5. I don't remember what I found though. I know the 6.5 has a different bracket or something to that effect.

[NH2112]

With new plugs, batteries, and the modified glow, I'd look at either timing or injectors as the cause of your hard cold starting problem. If your HPCA's not working that will make a big difference in the cold as well. Adjusting the timing is trial and error without a meter but if it starts well, runs well, and doesn't sound like there are 8 dwarves beating on the engine with tiny hammers while running then it's all good LOL If you don't have power at either of the green wires (top of IP and fast idle solenoid) on a cold start then the culprit is likely a bad temp switch (rear side of passenger side head.) If you have power then it means you have 2 separate problems - HPCA and fast idle. Jumper from B+ to HPCA and listen for the clatter, and B+ to fast idle and the engine should go to approx 800rpm. You'll have to blip the throttle lever just like setting the choke on a gasser, and if the RPMs don't rise try turning the screw on the solenoid because it could just be out of adjustment.

[GregCrabb]

It has fast idle on cold startup, with noticeable more chatter until it gets warm, then idles down and the noise changes as well. I guess I should just take it to Dixie Diesel and let them fine tune the timing. They are good people and are right across town. Last time I went by there, they didn't even charge me for an adjustment. Other than winter starting woes, it does great in warmer weather, doesn't smoke excessively, fuel mileage is pretty ok too. May just need a tweak.
Thanks

[blockw5chips]

The AC60G glow plugs do not get at hot as the OEM glow plugs. So the amount of time your glow plugs lite up might not be long enough. I switched mine to a manual push button for the AC60G glow plugs and it works much better. I can control how long the glow plugs stay on before starting. I was having the same problem here in north central Florida on the nite's it would drop down into the low 20's(I also work nite shift). I would have to plug it up at least two hour before leaving to get it to start w/o excessive cranking.
I saw the specs. on the different glow plugs but I can't remember where. If I can find them I get back to you. Good Luck:) I couldn't find the specs. but you can go to www.gm-diesel.com and lookup a fellow named Dieselolds and he can help you.

[GregCrabb]

In cold weather I get 18 secs of glow time.