I recently got my '85 SE running, but I'm running into an issue that is really killing it. It cuts out at higher rpms, but only when the engine is starting to warm up. It has plenty of power before it cuts out, then all of a sudden nothing. The more of a load the car has on it, say a hill or something, the lower the rpm that it happens. I first thought it was the fuel pump, but it's pumping normally. I just changed the fuel filter and it didn't help things either. Does anybody have some idea of what I can do? I'm not sure where to start. I still think it's fuel related, but I'm not sure. Could it be TPS or throttle linkage related also?

I'm posting in this forum because I'm not getting much help from the 1st gen guys. I figure you 13B guys can help me out a little more.

 

Yea, I was there today messing with it too. 1st of, the car has a hard start problem, and you have to press the gas a little for it to start. This isnt normal. Once it gets started though, it has a rock solid 750rpm idle. When revved in neutral under no load, it will go freely to about 5K , and then just stop and sputter. When driving under load, it will sputter much lower, as low as 2-3 K rpms. Its kinda puzzling... any ideas guys?

 

 

Keywords: under load. The MAF is your load sensing device... maybe there is some type of intake leak that is not drawing the flapper back far enough (causing the mixture to be off)?

3 things for high rev: Compression, timming, and a/f ratio. One of those things off, and you'll have a stumbling red headed step child.

 

if not the fuel pump, in tank filter, or engine side fuel filter, could be leaky or failing injectors.

 

edit:double post...

 

if not the fuel pump, in tank filter, or engine side fuel filter, could be leaky or failing injectors. sounds like the same symptoms i had when my fuel pump went bad. it started out as an occasional sputter, mainly when at constant cruise around 65-80 mph, then got progressively worse, until it did exactly what you described. the way i checked my pump was according to the haynes manual, i bridged the check connector terminal, and turn the key to on, listened at the fuel tank for a whirring noise that should stop after 15 seconds. if it doesn't stop than the fuel system is no pressurizing properly. check for leaks if no leaks in the fuel line nowhere start checking the injectors, pump, etc.

hope this helps

lamar

 

What I don't understand though, is why this would only do this when the car is warm. After I changed the fuel filter, I started the car, which was cold, and it easily and smoothly revved to redline, and I had much confidence that we had fixed the problem, only to find out moments later after the car had warmed up some, that I had not solved the problem. These problems you list, why would they only happen on a warm car, and not on one coming off a cold start?

 

do u have an airpump? the 13B's use the backpressure from the exhaust to open up the 5th and 6th ports, doesnt work w/o unless its rigged!!

at what RPMage does it kick out?

 

If the 5th and 6th ports didn't open, the car would still rev, but have a lack of power. Mine won't even rev. It's not the ports.

 

My car works a little different than yours does for this. On the FB 13B's, there is that same check connector, but I'm not sure that it should shut off after 15 seconds. When you turn your key forward, your pump comes on....In my car the pump does not come on until you're cranking the motor and the door in the AFM moves open slightly. When I crank the engine, I can here the pump come on because of this, but it does not come on when I turn the key to the on position, but not start the car. My point is, keep in mine this is not an FC, and may differ slightly. Also, I have an inline pump, so listening to the tank will yield nothing.

 

Anyone have any other suggetions?

I changed the fuel filter, which was original Nippondenso equipment and the odometer reads 220k miles on the body of this car. So it seemed promising when I saw that. I put the new filter in, started the car,and it freely revved to redline twice, so I told rxmfn7 to come on, and go for a ride. I drove about 100 feet or so, and it felt fine, but I hadn't got on it yet....I feathered the gas more and more, and it fell flat on it's face, doing the same thing as before. Any ideas?

It was also very hard to start today, I though I had flooded it for a little bit, but it eventually started. I noticed though, while cranking it, I'd let off the key and get out of the car, I could hear the injectors firing off. Sounded like a clear fast ticking. Just thought I'd throw that in.