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DOHC Wizards
Hi, I just killed it finally. heh. The car is a 1988 Fiero with a '95 LQ1. Recently the Cam sensor has been throwing a code and and the motor is Jerking violently when I try to feed it more than 35% throttle in 1st gear. The problem isn't as bad when I start in 2nd and give it a good run, but it still jerks around down low. Also something to note: after throwing the cam sensor code is sometimes also throws a Crank code. When the jerking gets violent enough it blows the INJ fuses. I put 25 amp fuses into the slots to prevent fuse genocide, but the only noticeable result was more bucking and jerking in start off rather than blowing a fuse. Every time the fuse((s) , inj 1 or 2) would blow the injectors would not squirt and the motor would just spin and not crank. If at a good speed when they blew, the motor would loose all power and come to a stop. This problem has been getting progressivly worse.
So today I put a computer on the ECM and was monitoring the symptoms to get a better Idea of what was going on. As soon as the bucking began it threw the Cam code and shortly after the Crank code. I was testing second when I gave it a really good run and the motor died. I reached down and replaced the blown INJ 1 fuse (which was blown) but the motor will still not crank now. I have checked all fuses and all are good. The motor throws a constant Cam sensor now. I dug the cam sensor out of the block and it looks fine other than being hot. The wires all look good until they run into the harness behind the engine and the firewall. Also something of note, the injector and cam wiring run together in the same tail. I pulled the ECM and checked C connector pin 10 (cam sensor) and the pin is fine.
So what's the problem? Would the engine not start at all if I finally did the Cam sensor in. I though it would crank but run extremely rough. Could replacing that sensor fix the entire system or do you guys think it may be a short in the harness somewhere? When we finished the harness we made sure the harness had no shorts or weak points but that doesn't mean one hasn't developed. My main question is will the cam sensor prevent the motor from cranking.
I abandoned the car in the campus parking lot and I have no means to lift the car so I can get under it to check wiring.
Please help.
-Paul
So today I put a computer on the ECM and was monitoring the symptoms to get a better Idea of what was going on. As soon as the bucking began it threw the Cam code and shortly after the Crank code. I was testing second when I gave it a really good run and the motor died. I reached down and replaced the blown INJ 1 fuse (which was blown) but the motor will still not crank now. I have checked all fuses and all are good. The motor throws a constant Cam sensor now. I dug the cam sensor out of the block and it looks fine other than being hot. The wires all look good until they run into the harness behind the engine and the firewall. Also something of note, the injector and cam wiring run together in the same tail. I pulled the ECM and checked C connector pin 10 (cam sensor) and the pin is fine.
So what's the problem? Would the engine not start at all if I finally did the Cam sensor in. I though it would crank but run extremely rough. Could replacing that sensor fix the entire system or do you guys think it may be a short in the harness somewhere? When we finished the harness we made sure the harness had no shorts or weak points but that doesn't mean one hasn't developed. My main question is will the cam sensor prevent the motor from cranking.
I abandoned the car in the campus parking lot and I have no means to lift the car so I can get under it to check wiring.
Please help.
-Paul
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