7.3 Power Issue - Diesel Forum

RunRed · 03-31-2006, 08:49 PM

Well I finally hooked up our 3000lb trailer, put all my crap in it making it maybe 4000lb (yet it is an enclosed billboard bigness trailer) and I can't believe how terrible it pulled it. Feeling wise it was awesome, made my truck ride better and everything but I could not go over 60, it just didn't have the power. The EGT's regularly got to 1000, I had to floor it up hills and then back down to get the momentum back up. Do all trucks like mine have this issue and thats why you put ZF5, turbos, on it? I would have thought it would have done better than this. There is a truck like mine at work with a 5spd and it gets up a goes a lot faster than mine. I think it may have 4:10 or higher though. I drove it home one night and at 45mph I thought the engine was gonna blow, even in 5th gear. So not sure if this is normal or not. Thanks for the help.

Willie · 03-31-2006, 11:21 PM

Mine would be the same, but there are a few other things to check, someone smarter than me will chime in and help you out [img]/ubbthreads/images/graemlins/smile.gif[/img] [img]/ubbthreads/images/graemlins/smile.gif[/img].

jdkline · 04-01-2006, 12:48 AM

They aren't designed to be fast especially with a load on it. If you're after big power you will probably be getting a gasser or a newer diesel. But if you want to spend some time and money on the IDI it can pull real good. A turbo kit would make a huge difference, as would swapping to a 4.10 rear end. But remember such a swap will give you higher RPMs and will cost you at the fuel pump. As Wille said, before you panic, check the fuel and air filters, and beyond that pop testing the fuel injectors and a timing check on the pump might also be in order. If you have two or more bad injectors it might not be a bad idea to change them all. Good luck,
J.D.

OkieGringo · 04-01-2006, 01:20 AM

How many miles on the Injection Pump? When I had mine rebuilt, even before I put on turbo, the new IP made a HUGH difference. Like night and day mucho bettero. OkieGringo

P.S. keep the RPM up above 2600 when pulling up hills/mtns, mine likes 3000 or more and will do it ALL DAY, until it runs outta fuel [img]/ubbthreads/images/graemlins/biggrin.gif[/img].

RunRed · 04-01-2006, 07:12 AM

It did seem to pull better when it was above 2600RPM but does it hurt anything running 3000RPM for 5 hours? I am not sure how many miles are on the IP or if the injectors are good or bad. How do I check all that? It runs fine but it does have a heck of a time in cold weather starting, never wants to start but once it does it is like a brand new engine, plus I have never seen any more than a little puff of white smoke at startup, never had smoke on the highway or anything.

Also, there is a ZF5 in the junkyard across the street but it is a 2WD trans, can you put on a different rear part to make it bolt on to a transfer case or is that all one piece?

shorthair · 04-01-2006, 07:57 AM

sounds like a pump or nozzle problem i think i'd pull the nozzles & have them pop checked for spray pattern & pressure

RunRed · 04-01-2006, 01:28 PM

Ok, I will test them out. BTW, I noticed you have air bags on your truck, do they make it ride smoother, I hate feeling every uneven part of the road. Thanks.

RunRed · 04-02-2006, 07:57 PM

Well I had to pull that trailer again the same route and this time I ripped off intake tube that the hood seems to cover, I didn't see how this was supposed to work so I took it off. It did better but I think a lot more can be made from this. I am still getting around to the injector pop test but unscrewed the nut on the top of each injector too see if they were all doing something, one of them (the second one back on the drivers side of the truck) made the truck almost die, I think it may be one that works well and the others aren't working as well since it all relied on that injector. I am gonna try and do a ram air setup to help out too. My exhaust is the stock 2 1/2" pipe, I cut off the muffler so I have a straight pipe and I stuck in a glasspack. Would a 3 1/2" make it much better? And my pyrometer is about 3 inches below the end of the manifold in the downpipe, today I hit maybe 1050 but I don't know how high I can go with the location it is in. Let me know. Thanks

Swervin · 04-02-2006, 08:36 PM

There are a number of things that you can do to get the best performance ourt of your truck, and they can make a big difference. I have added a turbo, run 4" exhaust, opened up the air, and then added my propane system. I pull an 30ft 5er that pushes alot of air, and I can run down the road very well. It all depends how deep your pockets are...

86lx · 04-02-2006, 10:09 PM

I had a 90 non turbo 5 speed with 3:55 before,I thought it was horrible for towing,I would pull a car on my open car hauler and was way dissapointed!! I had to floor it all the time.
I now have a 94 IDI turbo with a full 3" exhaust and some turned up fuel,WOW it tows great!!! I swear it has double the power,I towed this weekend to a mustang swap with my 24 ft eclosed weighing at least 9-10,000 lbs total and the truck did not struggle at all!! I had more pedal but I stayed off it at times to keep egt's under control.never went below 65 mph.
I did the same swap last fall with my 90 non turbo and could not get better than 45 up a hill in 3rd flooring it!!

I say put a turbo on it and go!!!

john94598 · 04-04-2006, 02:20 AM

You can buy a rear case for the zf to go from 2 to 4 wd sometimes you can get lucky and find the parts you need at a transmission shop, cases and such, if not go online there is a place zf trnsmissions or something like that, I will look it up and post but they are helpful and friendly and will talk with you, I believe they are in Dallas. Hope this helps