Guest bastaad525 Posted August 16, 2003 Share Posted August 16, 2003 I dont know what it wants from me... for a while now it's been running really good, almost perfectly, with the exception of the occasional hiccup on hard acceleration (had only happened once in a four day period). It would pull hard easily all the way to 6k. But now today, it's back to doing what it was doing before, basically it completely loses power above 4500rpms. Not just a stumble (though it does stumble noticeably still before continuing to climb), but a complete lack of any sensation of torque at anything higher than this. I went thru and cleaned ALL the connectors AGAIN, checked the timing again, turned the car off and on a few times, reset the ecu again, ... nothing helped. Pulled the plugs again and they all look perfect. It doesn't pop anything when it happens, it just feels completely flat. If I have noticed any pattern at all... well strangely and I think this must be some kind of coincidence... it seems to do this more often, the more fuel is in the fuel tank, which would make absolutely no sense to me. If all the sensors and fuel injectors are working right, the only thing I can think is maybe the FPR... if it was bad could it cause this problem? I'm also beginning to suspect possibly the fuel pump. I've already taken care of the couple vacuum leaks I've found and have spent a lot of time and effort trying to locate any more, but have not been able to. It's such a weird problem in that it's so sporadic, one day it's fine the next day it's running like crap. on a side note, I have to other questions I was hoping you guys could answer for me: 1. If I were to disconnect the 02 sensor and drive like this, what would the effect be? Would it be anything noticeable? Will it cause the car to run overly rich/lean/both? 2. Same question, only in regards to disconnecting the TPS instead of the 02. I'm really trying to gain an understanding of exactly what these parts do, and what the ECU will do if I take one or the other out of the loop. I've tried running the car with one or both disconnected just to see if it had any effect on the problems I've had, but it doesn't, as a matter of fact, it doesn't seem to have any noticeable effect at all. Quote Link to comment Share on other sites More sharing options...
yo2001 Posted August 16, 2003 Share Posted August 16, 2003 Any weather change? Quote Link to comment Share on other sites More sharing options...
Tim240z Posted August 16, 2003 Share Posted August 16, 2003 Try running the car with the fuel cap off. Tim Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted August 16, 2003 Share Posted August 16, 2003 nope still hot and muggy.. been the same weather for like two weeks now. How about this though, does this make any sense? Just on a hunch, I took some of brake cleaner spray I was using for all my electrical connections, and sprayed it in/on the crank angle sensor, and now the car is running really good again, I think even better than before. Even the stumble at 4500 was gone. Unfortunately the stumble came back by the time I got home But the car still running good no more loss of power after 4500. Anyways I'm just wondering if the CAS getting dirty could cause the kinds of problems I"m having? What about the o2 and TPS questions? I'm really really curious to find out the answer to that.... Quote Link to comment Share on other sites More sharing options...
Drax240z Posted August 16, 2003 Share Posted August 16, 2003 Most likely the CAS is a magnetic trigger of some sort, and not optical, in which case the amount of dirt you'd aquire in a couple hours of driving will NOT be the problem. Can't help you with the specifics of the L-jetronic system, but I know there are bosch books out there specifically on that system, I'd recommend looking into them. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted August 16, 2003 Share Posted August 16, 2003 heheh no one really seems to know much about this CAS... I really gotta get it swapped out for an '82-83 dizzy. I agree that it most likely has nothing to do with the 4500rpm stumble that stopped and then came back, but do any of you guys think that it could have been the cause of the larger problem of power just totally cutting out at high revs or sometimes whenever boost comes on?? Does the CAS only affect timing or does it also provide info to the ECU for other things? Heheh again... if anyone even knows exactly all that the CAS does. I'm even more pissed right now, just took a look in the buy/sell/trade section... someone selling a V8 JTR conversion with rebuilt chevy, running drivable car, for $2200... over $1000 less than I just spent to do my turbo conversion... and I coulda bought his car and KEPT my '72 and just left the built up N/A 2.9 in it or sold that car for MORE than it woulda cost to buy his... I'm kicking myself so hard right now... I coulda had a lot of fun in that car, holley carbs are something I actually understand and can figure out and work on... and I bet it's faster than mine is too fate is cruel Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.