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Newly acquired 97 civic ex auto with 177000 miles bone stock and well maintanced but was stolen and found the next day. It barely starts but fires up fast with a little gas. But after starting it, it won't rev past 1000rpm. No CEL. Tps and map aren't swapped, distributor is worn but nothings broken or that badly worn, tps is registering on my obd2 scanner and I'm getting a used one to put on tomorrow just in case, new ngk plug wires, plugs are ngk but are black and covered in soot.
I'm gonna try to get a hold of a used fuel pressure regulator, injectors, and maybe a distributor tomorrow at the junkyard. Anybody ever tried a used o2 sensor?
I pulled the intake filter (it was clean) and hose and verified the throttle opening with the pedal and my scanner showed it moving with the pedal movement. The intake manifold is pretty sooty as well.
I haven't pulled the crank pulley to verify timing but when the cams pointing up the 1st cylinder is at the top of its travel so it can't be that far off.
anything else I should look at or check?
so the cars running super rich, and maybe flooding it so much the engine is starving for air?
does anybody know what the o2 sensors should be reading?
and what the fuel trims should look like at idle?
Re: 97 civic ex won't rev past 1000rpm, barely starts
I pulled the fuel level sender and the gas tank looked clean. I wiped in the gas spout and it didn't smell sweet. I changed the rotor and the cap, and I got a used throttle body with the sensors and put it on, with no help.
so I did a compression test and got some bad results. I forgot to finish typing this last night and I'm at work without the real numbers but I got roughly:
Re: 97 civic ex won't rev past 1000rpm, barely starts
So when this thing was stolen, was it found parked somewhere or abandoned on a road or something? If the latter, they probably drove it hard and I would wager that the timing belt slipped, if the belt is old or if not that, it's probably something in the distributor, maybe the ignition coil is acting up. But it sounds like timing is way off.
Re: 97 civic ex won't rev past 1000rpm, barely starts
I would first check timing with a timing light while idling, then check if you're getting proper spark, then put a fuel pressure gauge on to make sure fuel pressure is right, and if all of that checks out, see if your injectors are working right.
Outside of that, you could compression test with the throttle open and verify it's not too low with the service manual. The values you have are too low, but I'm assuming you left the throttle closed (supposed to be open). And if your timing is off, you won't get proper readings anyway, which is another good reason to check timing.
Last edited by BigPapaBear; 06-24-2017 at 07:59 AM.
Re: 97 civic ex won't rev past 1000rpm, barely starts
Thank you for the replies.
I just got back from checking the mechanical timing and the cam is 180 degrees off....
At TDC
it looks off but I couldnt get my camera straight above it.
the timing belt looks in pretty good condition, do you think I could reset the timing and reuse the belt and tensionor for now?
Re: 97 civic ex won't rev past 1000rpm, barely starts
Oh wow, 180 degrees? I would be wary about reusing the belt or the tensioner. If the belt slipped it probably grinded down a bit and if the tensioner failed and caused the slipping, it's just going to happen again.
Re: 97 civic ex won't rev past 1000rpm, barely starts
No, it's not. There's a groove on the crank it all slides over. The cam is literally off by 180 degrees and that is your problem. I'm actually surprised you had it running, especially considering that the valves don't seem to be damaged (lucky).
Re: 97 civic ex won't rev past 1000rpm, barely starts
Right!! And it fires up quick I don't understand it.
how likely it is that the valves aren't damaged though? I meant it slipped a lot to get 180 off, do you think valves got hit during that
Re: 97 civic ex won't rev past 1000rpm, barely starts
I really don't know. If it's slightly bent, everything could still run, but poorly.
I had a scooter once that ate part of a gasket and left the valve open. Wouldn't start until I took a look and picked it out. It had 90psi compression.
It could all be fine. You could align the cam gear and then do a compression test before investing in parts to be sure. I think you need ~100psi with the throttle open for the piston to fire.
Re: 97 civic ex won't rev past 1000rpm, barely starts
a "slightly bent" valve in this motor will cause it to run like total ****. that belt does not "look" very good at all, and timing belts should not/ can not be judged based on looks. do the job correctly.
Re: 97 civic ex won't rev past 1000rpm, barely starts
Oh, in case it has to be said, be sure to turn the crank to about halfway between tdc and bdc before you take the belt off, so you don't hit the valves when turning the cam. You can take the spark plug out of one of the cylinders and measure where it's at with the dipstick to do this.
Re: 97 civic ex won't rev past 1000rpm, barely starts
I can't see any of the marks in your pictures. There are three notches in the edge of the cam gear. They should line up with the plastic pointer at 7 o'clock, and the edge of the head at 3 and 9.
Re: 97 civic ex won't rev past 1000rpm, barely starts
Originally Posted by egcivic775
Ha wait what?? That belt doesn't look good at all but you can't judge by looks??
yes, scientist. your belt looks well used, i don't know how your logic allowed you to come to the conclusion that it "looked good". most people with half a functioning brain would come to the conclusion that since the timing somehow jumped 180 out that the belt may be slacked or otherwise damaged, along with tensioner components, and not even think about reusing them. to my point about belts being hard to judge by looks alone- i've seen belts that LOOK much better than the piece of **** on your car break.
Re: 97 civic ex won't rev past 1000rpm, barely starts
Originally Posted by eghatch9295
yes, scientist. your belt looks well used, i don't know how your logic allowed you to come to the conclusion that it "looked good". most people with half a functioning brain would come to the conclusion that since the timing somehow jumped 180 out that the belt may be slacked or otherwise damaged, along with tensioner components, and not even think about reusing them. to my point about belts being hard to judge by looks alone- i've seen belts that LOOK much better than the piece of **** on your car break.
You should of read my last past. As the timing didn't jump but I was on the exhaust TDC. And I asked if that could happen and was told no.
where do you see the wear at so I know from now on?
Re: 97 civic ex won't rev past 1000rpm, barely starts
When you can see the tooth pattern on the flat side, it's a pretty old belt. You can often see bad by looking but you can't ever say for sure that it's good.
Do the notch marks line up? If the cam is properly timed, the question then is why is the compression so low?
Re: 97 civic ex won't rev past 1000rpm, barely starts
Originally Posted by mk378
When you can see the tooth pattern on the flat side, it's a pretty old belt. You can often see bad by looking but you can't ever say for sure that it's good.
Do the notch marks line up? If the cam is properly timed, the question then is why is the compression so low?
I ordered a new timing set and water pump last night and I got some better pictures of the cam
06-21-2017, 06:04 PM
97 civic ex won't rev past 1000rpm, barely starts
