Dead 6.2

[Truenorth]

Hello everyone. Got a quick question for you guys and I'm getting Eric to post it for me since my subscription just ended, and I don't know if it is worth renewing now 8-(

I have an 86 3/4 ton 6.2L van and it has 155K miles on it. Yesterday while pulling a heavy load it began to missfire for maybe a second at a time and then would go good for 10 seconds. After doinf that for half an hour it completly stopped running. At the time it completely stopped it lost all oil pressure on the gauge too.

Now when I crank it over with the starter it still does not show any oil pressure, and does not fire at all.

So, any ideas of things that might be relatively easy to fix to get this running? Or is it rebuild time? If it is rebuild time, then the van is scrap - not worth a rebuild. Only good thing on it is the proffesionally rebuild auto in it (5K miles on the rebuild and working great) anyone want to buy one of those if the rest of the van is scrap?

[kconnair]

Some guesses, but first, a couple of questions.. :confused:


Did the oil pressure drop prior to the engine running poorly?

Is/was the engine oil low?

Is/was the coolant low?

Was there any unusual smoke out of the tailpipes?

Is there water in the oil or oil in the water?

Does any obvious metal show on the dipstick?

Did it start making any knocking or grinding noises at the time of the problem?

Has the injector pump ever been replaced?

Could be a variety of things.

Some wild guesses based on the current limited info:

1) Bad Injection pump.

2) Bad lift pump.

3) Blown head gasket

4) Broken/skipped timing chain (Worn out)

5) Broken block - but I think it would have been accompanied by some really loud noises.

6) Broken Crank - but same issue as above.

If IP or timing chain, an easy (sort of) fix. If head gasket, still not too bad.

If it is broken timing chain that would explain the lack of oil pressure during cranking.

Crank/Block - Oh well.... :(

Good luck.

Kevin.

[Truenorth]

Did some more check:

Update from last night:

Oil pressure is back, just had to clean the sendign wire. So oil pressure looks normal.

Popped the purge valve open on the fuel filter and fuel flows when cranking - so the lift pump works.

Pulled one of the ruber low pressure lines off an injector and fuel flows out of there too.

Pulled the hard lines off the injectors and nothing but the occasional air bubble comes out it seems - maybe a tiny seepage of fuel.



So questions:

How do the 6.2L injectors work? Why low and high pressure? Does high pressure air, or high pressure fuel flow through the metal lines to the injector?

How do I test the injector pump? Electrical tests? Mechanical tests? Need adjustment? Need replacement? Best place to buy one?

What else should I check?

[john8662]

As for how the system work, the injectors are a high pressure pop system. The hard injector lines flow high pressure fuel to pop open the valve in the injector and spray diesel fuel into the combustion chamber. The rubber lines are on the injectors as a fuel return system, not all the fuel is injected into the cylinder.

A couple of things to check, if it won't start. There is a red wire on top of the injection pump found on the front of the engine in the V of the engine. Check to see that you have 12vdc at the red wire with the ignition switch in the run position. The red/pink wire that I am referring to is the biggest one going the pump itself, being in a van its in a tight spot. After you check to make sure you have power at that connector, keep th switch in run (wire hot) and plug it back into the injection pump, you should hear a click, if not try again (on, off, on, off, you will hear a click). This is a solenoid that turns the fuel on or off for the pump. so if this isn't working, that would explain why it won't start.

If that is all working, loosen one hard injection line (probably #8 cylinder or #7 on the back of the engine) because thats the ones you have acccess to on a van. Just loosen the nut 3/4" nut. Crank over the engine for about 8 seconds, there should be diesel fuel weeping out that location (nut gets wet where line goes in). If you have fuel there, then you're getting fuel from the Injection pump, if not then there is something wrong in the pump. You might want to try this several times, just to make sure, it could also be airlocked.

[Truenorth]

Well I had a look, and unfortunatly it is not just an electrical solenoid.

Looks like the injector pump, bled it and the fuel is barely seeping out. Turns out the hard starting I have been having for almost a year is another symptom of a bad injector pump.

So I called the logal GM stealer and they have the injector pump for the low, low
price of (he even said "are you sitting down?" on the phone ;) CDN$2100
plus CDN$1350 core charge.

A friend told me that some place named Diesel Injection Service in Ottawa
rebuilt his old ones a few years ago for around CDN$1000. Going to call
them today.

Anyone here on the board got a good hookup for a cheap injector pump? Let me know please if you do.

[john8662]

You can probably get a better deal on an injection pump from these places

They are both in the states,

Diesel Injection Service http://www.dieselpage.com/

Accurate Diesel http://www.accuratediesel.com

Diesel Services Group also sells Injection pumps, though not exactly cheap either, but they're in Canada, so that may help ya.

http://www.dieselservices.com