Help: Mack Midliner 8.8l, To Pull Injector, Must I Drain Coolant First?

[dozer]

Has anyone here done any fuel-system work on the 8.8L Renault/RVI engine in the Mack Midliner?

I have a misfiring cylinder (ID'd via cracking lines loose one by one), and I want to pull the injector and see what's up....and I'm wondering whether this engine requires the coolant to be drained before pulling injectors.

The Hino 6-cyl in my excavator has a big warning-sticker on the rocker-cover; saying that the coolant must be drained before removing injectors.

There's nothing like that on this Mack engine, and the service-manuals don't talk about it at all (at least, that I've been able to find so far).

Also, has anyone ever had one plunger go bad in a PE6SP pump?

I don't know that mine's bad, but when I was cracking the lines open, the line on the bad cyl didn't seem to 'blast' and mist the fuel that was spraying out from the nut and line, as much as the other cylinders did.

By the way, I need a good primer-pump for this PE6SP. The lockdown threads on this plastic plunger are stripped. If you have a known-good one you'd like to sell; or know of a good discount-place to buy one, please email me!

metal@fullwave.com

thanks much,

Richard

[Rob]

Has anyone here done any fuel-system work on the 8.8L Renault/RVI engine in the Mack Midliner?

I have a misfiring cylinder (ID'd via cracking lines loose one by one), and I want to pull the injector and see what's up....and I'm wondering whether this engine requires the coolant to be drained before pulling injectors.

The Hino 6-cyl in my excavator has a big warning-sticker on the rocker-cover; saying that the coolant must be drained before removing injectors.

There's nothing like that on this Mack engine, and the service-manuals don't talk about it at all (at least, that I've been able to find so far).

Also, has anyone ever had one plunger go bad in a PE6SP pump?

I don't know that mine's bad, but when I was cracking the lines open, the line on the bad cyl didn't seem to 'blast' and mist the fuel that was spraying out from the nut and line, as much as the other cylinders did.

By the way, I need a good primer-pump for this PE6SP. The lockdown threads on this plastic plunger are stripped. If you have a known-good one you'd like to sell; or know of a good discount-place to buy one, please email me!

metal@fullwave.com

thanks much,

Richard

I didn't drain the coolant in mine when I had the injectors "freshed up". It had the six individual cylinder heads as I believe yours does. Those pump parts are readily available at your friendly Mack dealer and really not out of line on pricing. I think mine was about $40.00 for a rebuild kit for the transfer pump including the stripped plastic plunger you mention. This was in 2003, so pricing may have increased a little since then.

Remember when timing that engine that the #1 cylinder is at the flywheel end. Save you a whole bunch of headache when running the overhead!!

Rob

[dozer]

I didn't drain the coolant in mine when I had the injectors "freshed up". It had the six individual cylinder heads as I believe yours does. Those pump parts are readily available at your friendly Mack dealer and really not out of line on pricing. I think mine was about $40.00 for a rebuild kit for the transfer pump including the stripped plastic plunger you mention. This was in 2003, so pricing may have increased a little since then.

Remember when timing that engine that the #1 cylinder is at the flywheel end. Save you a whole bunch of headache when running the overhead!!

Rob

howdy Rob,

Thanks much for the helpful info.

Is yours also the 8.8L (538cu) version?.....same model# as I listed in first post?

Yeah, while reading through the manual one day, I was getting a bit frustrated until I realized that they simply -had- to be numbering the cylinders 'backwards'.

One I assumed that, then everything made sense...

Hopefully I won't have to get into resetting the timing from scratch.

Although I do plan on 'turning it up' a bit in the future, my only goal right now is to get all six holes firing right again.

I found it interesting that there isn't any Anti-puff unit on this IP.

But then I considered that they've got this engine turned so far down, that this reasonably modern 8.8L DI is only putting out 205hp.....and I realized that the fuel-rate must be so damn low, they don't -need- an anti-puff...

Essentially, it's so far turned down that it's not really taking advantage of the turbo....not really using all that extra air. Runs real clean though!

For the near future, I'll just turn it up until it barely starts puffing, and call it good.

But I'd be real interested in hearing the details from anyone who's added an anti-puff assy from some other P-series pump onto this IP. Because a serious fueling/power increase would probably warrant doing this addition.

thanks again Rob.....and any additional notes or observations on working on this engine would be much appreciated!

Richard

[Rob]

howdy Rob,

Thanks much for the helpful info.

Is yours also the 8.8L (538cu) version?.....same model# as I listed in first post?

Yeah, while reading through the manual one day, I was getting a bit frustrated until I realized that they simply -had- to be numbering the cylinders 'backwards'.

One I assumed that, then everything made sense...

Hopefully I won't have to get into resetting the timing from scratch.

Although I do plan on 'turning it up' a bit in the future, my only goal right now is to get all six holes firing right again.

I found it interesting that there isn't any Anti-puff unit on this IP.

But then I considered that they've got this engine turned so far down, that this reasonably modern 8.8L DI is only putting out 205hp.....and I realized that the fuel-rate must be so damn low, they don't -need- an anti-puff...

Essentially, it's so far turned down that it's not really taking advantage of the turbo....not really using all that extra air. Runs real clean though!

For the near future, I'll just turn it up until it barely starts puffing, and call it good.

But I'd be real interested in hearing the details from anyone who's added an anti-puff assy from some other P-series pump onto this IP. Because a serious fueling/power increase would probably warrant doing this addition.

thanks again Rob.....and any additional notes or observations on working on this engine would be much appreciated!

Richard

I never really had any problems with mine as the engine and compressor had been rebuilt just prior to my acquisition. I had a rollback bed installed to haul cars which it done a real fine job of. The injectors were not touched during the engine rebuild so I wanted them gone through. Never did anything with the turbo, or pump and it still had the lead seals on it. I also had a funny noise in the drivetrain which turned out to be a couple of scored rocker arms. I replaced them all and the noise was gone. I ran the truck almost five years without a single breakdown or oil usage. Finally sold it when I slimmed down my operation(s) in 2004.

Only real drawback was that most parts needed to be furnished by a Mack dealer and they are about 100 miles from me so always had to be shipped. Fortunately they were right most times.

Mine never smoked either.

Rob

[dozer]

howdy Rob,

Mine also still has the lead seals on the IP-screw wires. Odo says 250K, but speedo isn't working; so I'm not sure of the actual miles. On the other hand, the guy who owned it for the past 10 yrs only used it once a week for local delivery....and for the most recent 3-4 yrs, it just sat. So it's probably 300K or less.

Interesting that you mentioned a "funny noise".....can you describe the noise at all?

While I was working on it the other day, while it was idling, I noticed an occasional 'tink' noise from (I'm pretty sure) the engine.

I was on the right side.....up near the front....I tried to localize it, but couldn't really pinpoint where it was coming from.....but it sounded like the front of the engine.

Wasn't a constant or regular (i.e. every stroke) type of noise....just occasional...semi-random timing, 1-5 seconds apart.....very 'light' kind of noise, but quite 'sharp', if that makes sense.

If rain doesn't stop me, I'm hoping to get the injector on #2 pulled today, so I can see if that's causing my dead-hole.

Richard

I never really had any problems with mine as the engine and compressor had been rebuilt just prior to my acquisition. I had a rollback bed installed to haul cars which it done a real fine job of. The injectors were not touched during the engine rebuild so I wanted them gone through. Never did anything with the turbo, or pump and it still had the lead seals on it. I also had a funny noise in the drivetrain which turned out to be a couple of scored rocker arms. I replaced them all and the noise was gone. I ran the truck almost five years without a single breakdown or oil usage. Finally sold it when I slimmed down my operation(s) in 2004.

Only real drawback was that most parts needed to be furnished by a Mack dealer and they are about 100 miles from me so always had to be shipped. Fortunately they were right most times.

Mine never smoked either.

Rob

[dozer]

Well, the injector -was- bad.....and having it reman'ed did make it so that cracking the injection-line loose on that cylinder now reduces RPM and adds roughness just like the other 5 cyls.

BUT....it did not change the white-cloud-when-cold situation at all. Looks like my IP is very retarded for some reason.

Since it's a new subject, I'll start a new thread for it...

Richard