I sold my Suburban and bought a '91 F250 4x4 with a 7.3 in it. It has 145,000 on it and has service records back to 25k miles with the oil being changed every 3,000 miles. What are some things I need to know about this truck/engie? I've seen posts about "SCA's" but would like to know more. The radiator and water pump were recently replaced so how do I know if I need any additives? Also, there is an issue with the truck, while driving down the road between 2500-3000rpms the truck seems to miss or hesitate and the tach drops to zero when it happens. I've been told that it's probably the cam pos. sensor, but would like to get some more input on it. Thanks.
nice find, as for checking the SCAs make sure you have green coolant if you do then it will have ford or fleetguard SCAs. There are others out there but the fords and fleetguard are compatible, just diff lables. Go to IH or fleetguard dealer and pick up some test strips. All you should need for now is the box of 3, instuctions on package will help you the rest of the way, or IH or fleetguard dealer will help with the rest.
I dont think you will have to worry bout the cps. I think it is the 94.5 and up that have the cps problem.
The tach on those trucks is driven by a tach sensor located just ahead of the injection pump, and is screwed into the gear housing. It is common for the insulation on the 2 wires going to this sensor to get pulled away from the wire inside, the wire then shorts out and causes problems with the tach. Check to make sure that the wires arent touching, or that the insulation isnt worn away. I dont think the tach dropping to 0 and the miss are related, because these trucks are purely mechanical in nature. Try running a bottle of Powerservice for a few tanks. Itll help clean the injectors and injection pump a little bit. If you plan to do any heavy towing, or increase the fuel at all, make sure you get a pyro gauge.
Well, I did replace the tach sensor and it did fix the driveability issue too. The wire insulation had pulled away on it. Unfortunately though, now the truck is in the transmission shop having the e4od rebuilt. He called me today to tell me that the third gear clutches had melted:doah: , this is gonna hurt.
In order to insure that this never happens again. Buy a Sonnax kit from a place like www.blackclouddieselperformance.com to firm and quicken up the shifts, and get the biggest cooler you can possibly find. The initial cost will be outweighed by the fact that your trans will never heat up again. There are several units out there that have their own thermostatically controlled electric fan just for the trans cooler. At just over $200 they arent cheap, but better than overheating another slushbox.
put a tranny cooler from a 6.0 in it th e 7.3uses a 9 row tranny coolor but the 6.0 uses a 25 row oil cooler
