48 replies to this topic

[24vman]

Hello everyone. After much tinkering with my 95 cl 454 trying to get it to stop goin into derate mode. I am really debating on just cOnverting it to manual injection. I was thinking a p7100 12mm pump. From what I read on here about others fixing the derate problem I think I can do this rather cheaper than countless sensers and ECM and ecu. Im thinking I can switch the pump and just leave the ECM alone and remove the electronic malfunction bulb and just go to work. I'm hoping someone can shed some light on this topic. Anyone know where to look for a p7100 mech pump?

Thanks in advance

[theakerstwo]

The mechanical engine has different pistons then the V mac. Also will you loose any gauges?

[theakerstwo]

Now that i think some more i beleive the piston could be used for a mechanical pump but would not be good to used a mechanical piston on a V mac engine. Reason is bowl design,the V mac has a greater amount of timing variration than a mechanical engine.

[24vman]

thanks in advance for the comment.. in 95 mack offered the same engine with or without manual injection. do you think they would go through the hassle of changing pistons according to pump style? as for gauges i was just going to hook them up manually also. i think the only one i would loose is the tach, pyro, boost, battery. and air are manual. rear and trans temps would also have to be rewired also. ignision switch would be ok.. basically i would leave the ecu and the ecm in and not pay attention to it. i have a 8500 series on there now, would the p7100 series mounting parts from a manual setup work on my truck to mount a manual pump?

thanks

[theakerstwo]

thanks in advance for the comment.. in 95 mack offered the same engine with or without manual injection. do you think they would go through the hassle of changing pistons according to pump style? as for gauges i was just going to hook them up manually also. i think the only one i would loose is the tach, pyro, boost, battery. and air are manual. rear and trans temps would also have to be rewired also. ignision switch would be ok.. basically i would leave the ecu and the ecm in and not pay attention to it. i have a 8500 series on there now, would the p7100 series mounting parts from a manual setup work on my truck to mount a manual pump?

thanks

In 95 there was three maybe four piston crown #s and one was for a V mac one for a 400 and one for a 275 to 300 and another for the 350 HP. So that would be four different pistons. Its in the bown design and also the compression ratio. The injector lines will also be different but basic you would remove the oil controlled timing advance and then install the 7100 P pump and it will have to be from a E 7 because the drive is shorter than a E6.I my self would repair the propblem with the V mac. It only electrial controls that give a problem and once you find the right guy to work on it your problem is cut down some.

[GearheadGrrrl]

Too much hassle for a 17 year old truck! Besides, the early VMAC versions were just electronic controls on a manual pump.

[84superdog]

I had issues on my 93 and it ended up being the wiring at the deutch connector near the pump. I know the early vmac's had a connector on the back where the harness enters the pump and the connector about 10 inches toward the back of the engine, they had so many issues they took the connector off the pump and hard wired the later ones(this was also a fix for the early pumps). I just unplugged the connector and jumpered the wires removing one at a time till i found the culprit then ran a wire outside of the connector soldered in and heat shrinked to correct the problem. I think the one I had at Hurst had an issue with a pressure sensor that made it derate, just my two cents but I wouldnt change the pump for a 30 dollar sensor or 2 bucks worth of solder and heat shrink.

[24vman]

In 95 there was three maybe four piston crown #s and one was for a V mac one for a 400 and one for a 275 to 300 and another for the 350 HP. So that would be four different pistons. Its in the bown design and also the compression ratio. The injector lines will also be different but basic you would remove the oil controlled timing advance and then install the 7100 P pump and it will have to be from a E 7 because the drive is shorter than a E6.I my self would repair the propblem with the V mac. It only electrial controls that give a problem and once you find the right guy to work on it your problem is cut down some.

thanks everyone for the info,, i understand how you guys feel about just fixing the problem andlooking for bad wires and such but being it is a 17 year old truck the wireing isnt factory condition on my truck. its pretty much a bad hair day caroded connctions, alot of the wire insulation is dry rotted. i just feel i can get a more reliable and maybe even better running truck by just omiting all of that nonsense. it could be ecm's, ecu's, sensors, i just want to get passed that once and for all.. would doing the timing be the same as on the e6 engines after the conversion?

[24vman]

Too much hassle for a 17 year old truck! Besides, the early VMAC versions were just electronic controls on a manual pump.

is there a way i could just replace the back half of the pump with manual back section?

[theakerstwo]

is there a way i could just replace the back half of the pump with manual back section?

Maybe some one can help you with the problem and if so start with telling me what is derating the engine and how have you been repairing it and do you do your own work and do you have the understanding of the electronics of the system?If you are asking me about your problem then i will say repair it right and then the problem should not come back. But you can not clear a inactive code and expect the problem to not come back.

[24vman]

Well. The truck usually derates on hills loaded or empty. It will be pulling good with 35psi normal water temp pyro about 6-7 hundred,oil pressure 60psi then without warning power just cuts right out. Boost will hit max 10psi pyro 2-3 hundred and water temp 180, oils pressure 60psi. I had a laptop on it, throttle position is 100%, I've replaced the torque sensor, speed sensor, and some kind of engine position sensor. The latest code I got out of it was 1st jake break error. But the jake works fine. Even tho I replace the speed sensor my speedometer still acts funny. If this info rings a bell please fill me in.

Thanks.

[24vman]

lso when I shut the truck off and restart it the problem goes away till I need the power again then malfunction light comes on and goes back into derate again.

[slpwlker]

out of curiosity hows your coolant level? had a shaker that when it got a little low would run great. get going uphill and it would derate

[24vman]

Coolant level is full. I check it every time I use the truck. The water temp doesn't make it even close to the red before it derates.

[theakerstwo]

Ok now we can help you. What code is this and have you tryed to repair it?Any time the light comes on and derates there is a code for just this reason and that is to tell you what is happening.Clear trhe codes and go drive it till it derates then tell me what code you come up with.

[84superdog]

the water level sensor in that tank on the radiator can cause a derate on hills if it wants to if you remove the plug from the sensor and jump it with a paperclip you can hit a hill and eliminate that sensor.

[84superdog]

read the code when it is active is the best way to fix the issue have the laptop there and when it derates what code does it bring up it will be the same one every time, other fault codes will log for different things when an engine is in derate mode, they can throw you off.

[24vman]

Usually codes 3-4 and 3-5 they tend to take turns. It's one or the other.

[24vman]

the water level sensor in that tank on the radiator can cause a derate on hills if it wants to if you remove the plug from the sensor and jump it with a paperclip you can hit a hill and eliminate that sensor.

Will I loose my temp gauge by disconnecting the plug on the radiator tank? Just jump the plug with a paper clip as simple as that?

[theakerstwo]

Usually codes 3-4 and 3-5 they tend to take turns. It's one or the other.

The flash code 3-4 means problem with the circuit or sensor on the timing event marker,located on the side of the ectronice governor housing.


The flash code 3-5 means problen with the timing actuator.This can be from a oil pressure problem to a electrical problem on the actuator. With out a manual and a reader you can not repair and no one else can with out hands on.