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joeheb
Senior Member
121 Posts |
 Posted - 11/09/2012 : 12:51:16 PM
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Driver complained about low power. First thing, pulled the codes, no codes, so I performed the following:
1. Removed EGR valve and cleaned it. Test drove and it made no difference.
2. Removed turbo and cleaned the vanes. Test drove and it made no difference.
3. Removed and cleaned the MAT (Mass air temp)sensor. It was pretty fouled up. Test drove and it made no difference.
4. Performed injector test with laptop, according to the test all injectors were firing.
Not trusting the test results, I checked the temperature at the exhaust manifold (old school) and seen that 2 injectors were week and 2 were dead. Yes the engine had a bad miss in it. So before I jump the gun and order $1600 worth of injectors, I figure I would fill the fuel filter with injector cleaner and run it and see if it would wake up those injectors. The injector cleaner worked its magic. That thing ran like a new bus! But.... when the engine cools down, it's sluggish again until the engine warms up, then it runs great.
Anyone have any thoughts on this one?
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willism
Senior Member
United States
103 Posts |
Posted - 11/12/2012 : 04:18:22 AM
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| See this on our older v8's when cold. Ive modified a temp sensor so it reads 162 degrees all the time so I can plug it in and have it fool the comp to running a injector test so it finds the weak injectors. |
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Bassman
Advanced Member
USA
467 Posts |
Posted - 11/12/2012 : 04:29:55 AM
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| After 50,000, if you have a miss, change the whole set of injectors. Also, check your EBS tube for restriction. |
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joeheb
Senior Member
121 Posts |
Posted - 11/12/2012 : 05:20:43 AM
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quote:
Originally posted by Bassman
After 50,000, if you have a miss, change the whole set of injectors. Also, check your EBS tube for restriction.
Forgot to mention that I cleaned the EBP sensor and the tube to no avail. I think that bus is right at 50,000 mi, I might have to replace all injectors if it keeps acting the way it does. |
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joeheb
Senior Member
121 Posts |
Posted - 11/12/2012 : 05:22:46 AM
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quote:
Originally posted by willism
See this on our older v8's when cold. Ive modified a temp sensor so it reads 162 degrees all the time so I can plug it in and have it fool the comp to running a injector test so it finds the weak injectors.
That's a genius idea, care to share how you modified the sensor? According to my injector test, all injectors were firing. |
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willism
Senior Member
United States
103 Posts |
Posted - 11/12/2012 : 05:45:45 AM
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| Bought a temp sensor broke it apart and soldered a couple resistors to the leads (don't remember what size resistors 2 20k ohm i think) and molded silicone around the modified sensor to protect the resistors. Was just sticking resistors in the wiring harness but after dropping a few i just decided to make up the little tool. |
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joeheb
Senior Member
121 Posts |
Posted - 11/12/2012 : 05:53:15 AM
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| @ willism, I'll have to give it a shot, and see what happens. Thanks. |
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57fan
Active Member
United States
49 Posts |
Posted - 11/26/2012 : 7:39:53 PM
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| For what its worth, some guy was selling "performance Chips" on evil bay a few years ago to increase horse power in your car. Me being the curious one, I bought one for 1 cent plus shipping ($2.99) and that is exactly what I got. A resistor with a paper telling me to connect to the ECT sensor. In this case the resistor showed the engine being "cold" to fool the ECM to think its cold and to provide more fuel. (more fuel equals more power). Never used it. The resistor is available from radio shack for under a dollar. Great scheem he had going. LOL |
Lead, Follow or get out of the way! |
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joeheb
Senior Member
121 Posts |
Posted - 11/29/2012 : 05:24:21 AM
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Well folks , turns out the injectors needed replacing. New injectors made all the difference in the world. One would think they would last more than 50,000 miles...but it runs like a new one now.
@57fan that guy's a genius!!! lol.. |
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Bassman
Advanced Member
USA
467 Posts |
Posted - 11/29/2012 : 11:05:14 AM
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| I replace our VT365 injectors after 50,000 miles when I have the bus into the shop. That's less than today's spark plugs! With 22 of these buses averaging over 180,000 miles each, we have seen the pattern over and over. The only recommendation that I have for you that we haven't tried yet is to use 5w-40 synthetic oil for the life of the injectors and see if that helps the wear. It certainly helps with cold starting once they get older. |
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joeheb
Senior Member
121 Posts |
Posted - 11/29/2012 : 1:09:23 PM
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I've tried talking to my boss about switching to full synthetic before but he would'nt hear of it. If i can convince him that it could possibly extend the life of the injectors then maybe he'll consider it. Thanks for the advice.quote:
Originally posted by Bassman
I replace our VT365 injectors after 50,000 miles when I have the bus into the shop. That's less than today's spark plugs! With 22 of these buses averaging over 180,000 miles each, we have seen the pattern over and over. The only recommendation that I have for you that we haven't tried yet is to use 5w-40 synthetic oil for the life of the injectors and see if that helps the wear. It certainly helps with cold starting once they get older.
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mastertech
Senior Member
178 Posts |
Posted - 11/30/2012 : 1:32:09 PM
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| If your getting 50,000 out of a set of vt365 injectors consider yourself lucky. Ours started failing at around 30,000. |
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joeheb
Senior Member
121 Posts |
Posted - 11/30/2012 : 2:32:43 PM
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| 30,000!?!?! Wow! I thought 50,000 was too quick for injectors to go bad. IMO International screwed up using EGR system to meet EPA standards, I mean think about it,why would you recirculate dirty carboned up air through the intake? You carbon up all the sensors in the intake manifold and you're getting dirty air in your cylinders and carbon up the injectors, which probably shortens the life of them. Just saying... |
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mastertech
Senior Member
178 Posts |
Posted - 12/02/2012 : 08:54:02 AM
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VT365 injectors go bad because of wear in the coil/plunger assembly causing stiction from sludge buildup. Which is why clean good oil is so important. If you have ever taken apart any of the coil valve systems in the diesels you will see what I mean. The coil is an electromagnet which will collect all the super fine metal particles from the oil that even a filter cannot remove. It will build up around push block of the spool valves and gum up the works slowing them down and messing up the function. Take an ICPR apart and see what I mean.
I think running synthetic oil and bypass filtration with large magnets in the system would do wonders for injector life. |
Edited by - mastertech on 12/02/2012 08:58:40 AM |
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Bassman
Advanced Member
USA
467 Posts |
Posted - 12/03/2012 : 02:07:37 AM
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| Also, don't forget that the oil coolers which are marginal at best become clogged and are in line with the EGR coolers on this engine. Overheateded oil also contributes to the injector bores wearing on this engine. |
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joeheb
Senior Member
121 Posts |
Posted - 12/03/2012 : 05:25:21 AM
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| @mastertech, @Bassman both of you make absolute sense. I never really thought about the internals of the injector wearing like they do, I figured they mostly fail due to the jet being so clogged beyond cleaning to where fuel can't pass through the micro size holes. Thanks for your input. You guys are very helpful in this forum. |
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Fastback
Top Member
720 Posts |
Posted - 12/03/2012 : 06:56:09 AM
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| Another contributing factor on VT365 injector wear is that roughly 1 gallon of dirty engine oil does not drain out during a proper oil change, all it may take is one extended drain interval to get the injector wear process really rolling. |
Why yes, the ORIGinal CHARGER is a Fastback |
Edited by - Fastback on 12/03/2012 06:56:30 AM |
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2008 VT 365
