JoeH

Other than that they're great engines. We have a 1979 engine still in daily service. It's had a couple camshafts in its life, but we have the donor engines to keep it going.

Ditto on pics. VIN would tell us a lot as well about which HP rating the engine has. A 285-300 HP usually got paired with a 2 stick 6 speed, whereas the 237 HP usually got paired with a single stick 5 speed. Unfamiliar with cruiseliners, so idk what transmission shifting arrangements they had. The engines aren't entirely bulletproof, I assume this truck will have 2 valves per cylinder, not sure if the 4v per cylinders were out in 1980. Weak point on these engines are the lifter tappets on the camshaft. The lifters use a flat carbide disc that rides on the cam, and these carbide faces can crack, a piece falls off and the sharp remaining edges cut the lobe right off the camshaft. I think there's a company "Berry Cams" somewhere in the country that can weld a new lobe on there, but I know the cam is no longer available through Mack, so you're on your own to repair/find donor cam and tappets.

https://www.paiindustries.com/ Here's one more resource for you, if you make an account on this website you can access tons of parts diagrams and part numbers for your truck. Can't buy parts through their website but you can take part numbers and get them from one of their dealers.

FYI your manifold could be eroded. My 95 was when we bought it, back cylinder. Caught it when the engine hydro locked after a rain storm shortly after we bought it. Pulled the manifold, used cast iron welding rods then ground it back down, haven't had a problem in ~13 years since.

At this stage of the relationship "Hon" may become appropriate!🤣

Also how's your batteries? Maybe you have a couple battery cells failing and you don't have enough juice to turn ecm on or work the starter. Gotta start with the basics, not the expensive crap!

Title is No crank No start

Don't have any experience with MP's, but it's possible to have a "dead spot" on the starter or have a bad relay on the starter itself. On my 12v Cummins I had to take jumper cables from the battery right to the starter motor once to get back home. But my 12v has slot less electronics....

Book indicates it stops it from getting in the Control Valve. Never seen an AC in person though. Don't know much about them.

That's where the book is invaluable, it'll tell you exactly what each component does.

It protects the "Control Valve" from "coking."

Book.says it's an oil condensate filter to keep oil out of the system. Depending on Build Date of the engine it may not have had one from factory. I think the pages I sent indicate May 2004 as the change over time frame.

Couple more screenshots from the Book showing some things.

Pages 84&85 for example...

https://macktrucks.vg-emedia.com/ProductDetail.aspx?ProductId=6148 Here's a link to download (free) the Mack Manual for your engine. Click on "View File" to download. It may have a lot of helpful info for you on this dumb EGR system's plumbing.

A little late to the Party, but the Googleweb is a great friend, sometimes. Punched in "Mack AC400 Engine" on an image search and was met with more than a few choices on pictures of engines minus truck frames in the way...

With that bonnet I keep thinking it looks like a Ford L8000.

Glad we caught it before it dropped a valve or something worse.

Truck is at the dealership getting the go-over and so far with the stumble all they've found is a failing valve rotator, which yielded some small bits in the oil pan and an out of adjustment valve. Cam checks out ok, they don't suspect eup's as there's no knocking sound from the eup "jumping" off the lobe. Cam also looks great from underneath, and they measured the cam lobe heights with dial indicator on the valve stems. They'll put 2 reman cylinder heads on it, plus whatever peripheral junk goes along with that. It's gonna cost an arm and a leg, but I have no doubts regarding their competence, and it's gonna be done a whole lot faster than doing it ourselves. And we need this truck done ASAP.

Long shot but is this camshaft changes file still available? Can't get the link to work.

No the AI ones are good, the AC ones are shit. Sorry bud. The AI ones use a bump on the exhaust lobes to pop exhaust valves open during intake, combined with restrictive exhaust manifold and turbo to create back pressure. That's the EGR system. Pop some pre AI engine parts on there instead and you're done, good to go, and no cop will ever know it's deleted, and no effect on computer software. The AC motor has that external EGR, vgt turbo, extra sensors, different eecu....

Not saying you can't delete Macks, but there is very little aftermarket support for it.

https://macktrucks.vg-emedia.com/ProductDetail.aspx?ProductId=6543&GroupId=-1 You're looking for Mack manual 8-201, if your dealer is halfway decent they should be able to order it for you, but you can also download it for free by clicking "View File"

My absolute favorite is 23-021 https://macktrucks.vg-emedia.com/ProductListing.aspx?keyword=23-021 It's a data program on a flash drive that has just about every Mack wiring diagram from 2000 forward. Engine wiring, chassis wiring, transmission, vendor engines, emissions wiring... Well worth the $180, though your 1995 won't be in there.

Macks emedia website is chock full of free downloadable manuals as well as buyable paper copies either through website or your dealer.