Is there any way to know if two cylinders are leaking between each other by cranking it as the battery is dying? The battery just so happen to be dying and it cranks fast twice, then feels like it lugs twice, then fast twice and lugs twice as if 2 cylinders are getting compression and the other two aren't. I checked the cylinders as well and it is just barely wet inside with gas, no pooling of oil or coolant or anything.
Is there any way to know if two cylinders are leaking between each other by cranking it as the battery is dying? The battery just so happen to be dying and it cranks fast twice, then feels like it lugs twice, then fast twice and lugs twice as if 2 cylinders are getting compression and the other two aren't. I checked the cylinders as well and it is just barely wet inside with gas, no pooling of oil or coolant or anything.
Is there any way to know if two cylinders are leaking between each other by cranking it as the battery is dying? The battery just so happen to be dying and it cranks fast twice, then feels like it lugs twice, then fast twice and lugs twice as if 2 cylinders are getting compression and the other two aren't. I checked the cylinders as well and it is just barely wet inside with gas, no pooling of oil or coolant or anything.
Is there any way to know if two cylinders are leaking between each other
Leave the spark plug out of one of them. Crank the engine by hand (socket on the pulley/balancer bolt). If the cylinder with the plug is just about as easy to crank on the compression stroke as the one without the plug, the one with the plug is leaking.
Thank you for the info. I'm going to try that tomorrow morning. I wanted this to be running project, But it's turning out not to be that way and if the head gasket went because of the coolant being absent I can only imagine the block or head is warped and I'm not paying for what might as well be a rebuild if it's all apart already. I'd rather throw the money into a swap I want.
I'm either going to sell it or do the 4.9 carb swap due to my budget. I love the carbed engine sound,and I need money for the manual swap too but that's only if I can sell my cavalier that's been sitting around.
I think with the carb 4.9 I would only need mounts, custom distributor, and an adapter plate for the carb, other than that it's plug and play right? Pretty sure that's what the threads were saying.
However, I haven't heard anything about what computers are or aren't needed and what to do with the one in the fiero already. Doesn't other stuff run through there than just engine electrical as well as driveline? Wouldn't I need the transmission hooked into something or do you just not have to plug that in?
[This message has been edited by FireStorm102389 (edited 09-02-2015).]
Aside from the dying battery, I suppose it's possible for it to give out an inconsistent power to start, idk but I had all but 1 spark plug out and ran around to each cylinder compression stroke, each switching the spark plug to the corresponding cylinder and I felt compression on each one, but I suppose that doesn't mean there isn't a compression leak...
I checked the resistance of the wires and plugs, plugs read about 5800 ohms and one read 7300 about. Spark plug wires all read about right. longest read the most at 12000 something, then next was 11000 something, then 7000 and the last was smaller yet, I don't remember. Also checked the one to the cool and that was 4000 something I think. I'm assuming those numbers are about right? I'll have to charge the battery by putting it in my other car and driving it around for a while and maybe that will help, I have it all connected to jumper wires all the time and I know it's going to kill that battery if I keep doing it like that. But it should at least sound like it's going to start at minimum.
If you have spark at the plug that IS enough to start the car. It won't run under load if the spark is weak, but its enough to start the car and at least get some backfires or something. If you are just cranking, with no sign of starting, I'd look else where.
I'd even think about swapping in a different Computer (ECM) to eliminate that as a problem, but that seems unlikely since you had it running before.
Also, even if you have one bad cylinder, the car will still run on 3 cylinders and run quite fine at idle. You'd need to have 2 or more bad to prevent a start up. You can also eliminate this as a problem by renting a compression gauge from Autozone.
Yeah, I put the battery from the fiero in my main car and drove that to work seeing as it's a 35 minute drive one way figuring it will fully charge the battery. That way when I put it back in the fiero it's got a strong charge. I'll try and crank it, most likely the weak battery wasn't the problem but at least I can say I tried. Also that way when I do rent a pressure gauge, I can actually crank the engine to actually verify the compression accurately.
Summary so far. Spark plugs and wires appear to be good, new and verified installation of my exhaust gasket and manifold (although I left the heat shield out on accident), oil is new synthetic 5w30, water pump and housing got cleaned and all new gaskets put in (due to the new water pump being installed with rtv and the housing had a leak because of that), filled and bled the coolant. I had it running after every step except the last one where I replaced the exhaust manifold.
[This message has been edited by FireStorm102389 (edited 09-03-2015).]
That slow, slow--quick, quick cranking thing doesn't necessarily mean anything. I've had cars do that when the battery is low.
Bear in mind that I know nothing about the 2.5L 4-cyl, but I'm still curious about the ICM. If it got hot, and is old...
Is fuel getting to the valves?
Usually cars have an optimal operating temp; outside the preferred operating range, the engine doesn't run as well, and bad things start to happen. No melted wires? Vacuum tubes all look good?
Thanks for the photos of the sheets, I'm going to do a compression check first and if that comes out good I'm going to run through those sheets. I'll also pick up a vacuum hose that's missing off the intake for the intake manifold temp I believe it is.
One other thing. The wire harness that goes to the ac pump has 3 connectors that come off of it, one is obviously for the ac pump, but what are the others for? The kid I got it from said they were for the ac system but I never really thought about it. Could that be something that needs to be hooked up? I'm thinking of deleting the ac.
Originally posted by FireStorm102389: One other thing. The wire harness that goes to the ac pump has 3 connectors that come off of it, one is obviously for the ac pump, but what are the others for? The kid I got it from said they were for the ac system but I never really thought about it. Could that be something that needs to be hooked up? I'm thinking of deleting the ac.
High and low pressure switches on the back of the compressor.
------------------ Anything I might say is probably worth what you paid for it, so treat it accordingly!
That slow, slow--quick, quick cranking thing doesn't necessarily mean anything. I've had cars do that when the battery is low.
Bear in mind that I know nothing about the 2.5L 4-cyl, but I'm still curious about the ICM. If it got hot, and is old...
Is fuel getting to the valves?
Usually cars have an optimal operating temp; outside the preferred operating range, the engine doesn't run as well, and bad things start to happen. No melted wires? Vacuum tubes all look good?
I haven't seen any melted wires, and all vacuum hoses look good except the one that is missing for the intake temp, which I'll be buying soon as well as the 180 degree thermostat due to the egr system not being there. I don't have any pictures that I can post on here due to not being able to post them just in here. I click image and it tells me to add a url.
Ah, Well idk if it's bad or not, when I drove it the one time all the gauges worked, they weren't sporadic but they weren't smooth either. They did a little shaking, mostly the oil pressure one bobbing a little each way but if these are controlled by magnetic push and pull then that's to be expected for an older vehicle as far as I know.
Cylinder 1,2, and 4 read between 120 and 150 and cylinder 3 read 100 the first time and 90 the next, I'm assuming it should still start though. I'm going to try changing plugs out and see if that does anything. I saw spark, it's getting fuel, has compression, timed correctly enough to start it, and it's getting air obviously.
Ok, I haven't tested mine, and don't know what the compression is supposed to be on the 4-cyl, but when we worked on racing engines, everything had to be the same, same weight for each valve, for each rod, each piston, etc, same compression on each cylinder. I figured they came that way from the factory, since we were racing against factory teams. 30psi of difference in compression can't be acceptable. IIRC, gas cars are about 12:1, bikes about 18:1. I don't remember very well, but something doesn't seem right.
[This message has been edited by tshark (edited 09-06-2015).]
Cylinder 1,2, and 4 read between 120 and 150 and cylinder 3 read 100 the first time and 90 the next, I'm assuming it should still start though. I'm going to try changing plugs out and see if that does anything. I saw spark, it's getting fuel, has compression, timed correctly enough to start it, and it's getting air obviously.
Weak for sure, but that should be enough to start.
Yeah I have to get it running properly before I do the timing. Now that I get everything but that fixed I can test the fuel system. Unfortunately I woke up late today and won't be able to test it but hoping this week sometime. Baby kept me up all night.
Edit: I heard too that the fuel pump needs to be putting out a certain pressure because of its low it won't even start. I did notice that at first it seemed fine when it was running but after I got all that stuff fixed, when my girlfriend started cranking it, it had a big burst then it kept getting smaller and smaller. Pretty much only got one nice burst, and I don't hear it running anymore, but I will give that test wire a 12v charge when I get home tonight and see if it even turns on. It was sitting so it could be the pump or the filter I bet. I don't even smell gasoline anymore so I don't think anything became disconnected, besides I can even hear it run anymore. Hoping it's not the computer, I'm sure that's more expensive than a fuel pump.
[This message has been edited by FireStorm102389 (edited 09-08-2015).]
Right now he has to figure out a way to get it started. He can worry about timing later.
The thing is, it started and he had it running earlier... and supposedly had it timed correctly. I was therefore surprised that he didn't know where the ALDL was.
No, I never had it actually timed, it was just rough timed. I had so much stuff to do to fix it that I was going to actually time it once I got everything else done. So once I get it running again, since all else is finished, then I will rent a timing light and actually time it correctly.
The Haynes manual was very vague and that's why the guy before me couldn't figure out the timing, I new it wasn't timed correctly by hearing it, was trying ignite the wrong cylinder, so I pulled the distributor and actually got it to the point where I could get it started. Problem was the manual was vague on which post was supposed to be which cylinder. That's what that thread was about, but I got that all done. Had to do the water pump and housing gaskets, bleed the system, change out the exhaust manifold and gasket, all that done, previous manifold was split so o wanted to change all that and get the engine all good before finishing with timing.
[This message has been edited by FireStorm102389 (edited 09-08-2015).]
No, I never had it actually timed... I will rent a timing light and actually time it correctly.
If you plan to own this (or another) Fiero for any length of time, don't rent a timing light... buy one! Go to eBay and get an inductive timing light. If you're lucky, you could get one for as little as $15 (including shipping)... such as some of These have gone for.
[This message has been edited by Patrick (edited 09-08-2015).]
Found a thread on it actually and found out that the ecm isn't getting power, no cel light, no fuel pump prime, etc, etc.
Followed the wires by the battery and something sparked and all of a sudden the lighting system sprang to life ( lights didn't work before and I left the switch in the on position). No idea what happened but now the lighting system works and I couldn't duplicate the spark.
Checked the flushable links and they all looked good, so I followed the wire harness, it's stupidly routed through the belt and the alternator fan cut through the harness housing and 3 wires( dark green wire, light green wire, and even power wire). I'm going to have to unplug the harness by the battery and reroute it so it's not growing through the belt( also the starter wires since they are also routed through the belt).
What are the other 2 wires for that were cut? And is that the way the harness is routed from factory?
[This message has been edited by FireStorm102389 (edited 09-09-2015).]
In case anyone is having the same or similar problems and stumbles on this thread, I soldered the 3 wires back together and wrapped it all back up as well as re routed the harness to prevent future problems. Hooked everything back up and she started right up. Runs a little rough but the timing isn't set yet, probably do that tomorrow.
Moral of the story, double check everything as well as physically look and feel everything especially when it comes to wiring.
