dgoad

Hello Gents,
Raylo makes some good points, but my engine has a MAP sensor instead of the newer MAF ( Mass Flow vs. Atmospheric Pressure ). My MAP sensor just has a small hose attached to the intake manifold. My engine also has an electric servo driven EGR valve with NO vacuum attached. I am still getting an error code about the EGR valve and I will have to replace it at some point, however, I did take it off and clean it and manually shut the return gas valve. I put the unit make on and I left the power control connector unplugged so it would not move. This made no difference in the engine problem. I did order a CPU today. I did take the cover off of the old one. I did not see anything that was out of place with the unit. No burnt or colored areas. Nothing. Tomorrow or maybe Saturday, I am going to take my scope outside and put it on the injector leads and see what the pulse width I am really getting at the injectors. This is more of a question in my mind than any thing else. I want to see if it is the same as what the scan machine says that the CPU is putting out.

Yea, the truck was running and the alternator went out back in March. A new one was installed. That was the only and I mean the only part on this truck ( other than tires and brakes ) that is not original. It has almost 290K miles on it. I know, but it's true! I don't know if he used jumper cables or not, maybe so. That can cause electical troubles with computer controlled engines. But, it did run for several months after the altenator change out, I guess we will see next week. My son tells me that over a several week or maybe a month time frame the engine was starting to not quite run right. He noticed that if he stepped on the gas it would bogg down for a second or two before picking up speed. He also noticed it starting to idle a little rough, talking here about a miss or two every 10 seconds or so. The day in question he told me that he drove the truck about 5 miles to work and that about 5 or 6 blocks away it started really running rough and that he had to work the throttle to keep it running. Then at one of the lights it quit altogether. He had a hard time getting it cranked again and he had a hard time getting the rest of the way to work. Remember now, since it has been here I can say that the engine is and has been running RICH, very RICH. His original injectors were dripping down the middle of the spray on one of them and down right leaking with a small stream in the other one. It may ( I am guessing here ) have been that the injectors just got to the point that the CPU could not help over come the fuel anymore and that is why it runs so bad. The plugs that I pulled out, original and in bad shape, were not oily. They all were just jet black with a black power like dust all over. The new plugs, that have maybe 10 minutes on them, look the same. It now seems to me that the engine had/has a RICH fuel problem and I thought that new injectors would save the day. The fact that the engine is still RICH troubles me and I hope the CPU will be the answer. Later guys and gals, more to come. And the CPU should be here middle of the week. As always, if you run across any info that might help answer the big question, please pass it on. Later.