Question:
1990 Camaro won't start?
Mark G
2013-09-20 07:37:47 UTC
Hello. I have a problem with my 305 Chevy TPI engine. The engine cranks but will not start. I sprayed gas into the plenum and the engine fired for a short time, so I assumed it is a fuel problem. I tested the fuel pressure with a pressure tester an got 48-50 Lb. at the fuel rail. I tested some of the fuel injectors with a noid light. The light flashed several times while cranking the engine. I only tested 5 or 6 injectors but they all did the same thing. Not sure how a noid light is supposed to pulse but it seems to flash very fast. I also replaced the MAP sensor. What other sensors, or test can I do to find out why I'm not getting fuel to the cylinders. For the sake of argument I'm getting fire to all cylinders. A LITTLE HISTORY ON THE CAR: It died while idling in the driveway, has not started since. Before that the car seem to not have the power it did have, but I think this may have been a timing issue. The ECM has been replaced several years ago, not sure why. THANKS in advance.
Six answers:
dig
2013-09-20 13:57:14 UTC
Okay, your description is confusing. :Spraying fuel down the throttle body made it fire for a minute? That's a fuel problem. Having a lite pulse on the injectors doesn't mean they are working. That pulse is only one of 3 signals needed. WHY did you replace the MAP? Did it blow a code or something? It can effect fuel delivery, but not stop it. Check the connections on it anyway, and make sure the vacuum line is installed correctly at both ends. Doesn't hurt to check your own work.



Just for grins, before you get into this fuel stuff, for your peace of mind pull 1 plug (number 3 is about the easiest), Put the wire on it and ground it. Make sure it's sparking. That should check out okay. If not, you can address it from there.



I have seen fuel pumps and fuel filters do stupid stuff on TPI motors. Did you check the fuel pressure with the engine cranking or just the key on?



I've had 2 or 3 fuel pumps fail on me. they will run, shut down all of a sudden, then fire back up later as if nothing is wrong. They are a pain in the petute to change, as you have to drop the tank, which means the exhaust has to be unbolted and lowered, along with the rear end.



If the filter is plugged, it can supply pressure with just the key, but won't let enough fuel through to make the engine run. Check the fuel pressure while someone is cranking the engine over for you. It might drop almost to 0. If that's the case, go from there. It'll likely be fuel pump or filter.



If the pump and filter check out, and there is no check engine lite codes, then about all that's left is the ECM or a broken wire/plug at the ECM. Injectors don't all go out at once. You will invariably come up with a miss on one cylinder. They are independant as the spark plugs, I don't even think they CAN effect each other.



The ECM is located up under the passenger side dash. Remove the lower dash cover (down by where your feet are) push the seat back and lower the back till you have enough room. Then if you lay on your back and look up you will see it. It's a silver box with 5 or 6 plugs in it. You will have to unscrew one or 2 bolts to get it out.



Check for pins that have backed out of the plugs and for broken wires (they can snap off right at the connector). Unplug all the plugs (you will have to first remove some comb locks - look and you will see what I mean on that). When all the plugs are loose, drag the computer out where you can see it and check all the pins. Look for rust or nasty dirty pins.



Put the ECM on the work bench and remove the top cover. DO NOT stick your fingers in there because static from your hands can damage the chips. Look for burn marks or discolored/swollen components. If you can't see anything wrong, put the cover back on it. Put DIELECTRIC GREASE on the male pins, and replug it in. Don't install it up under the dash. See if your lubing and reseating plugs fixed it. If not, If not, you can look up automotive ECM testing in your area and take it to someone with the test eq to make sure it's alright.



NOTE TO SAVE A LITTLE MONEY: If you call a good parts house and give them the part number of the ECM, they should be able to tell you what year cars it fits. Take the list and hit the junk yards.



Good luck, and you can PM me if you want.



Dig
2016-03-10 04:55:19 UTC
If it is, in fact, the car turning over but not starting, I would suspect a couple of things that are fuel supply related. You might have a leaking fuel injector that's flooding the intake - making a restart difficult, since the fuel that floods the intake needs to either evaporate, or get "blown" through. You could have poor fuel rail pressure as a result of leaking injectors and/or a bad regulator, or you could actually have a vapor-lock condition in the line as a result of excessive heat to the fuel line as a result of running too close to the headers. Does it take long (greater than 2 seconds) when you start it in the morning? If so, you may be having issues with the fuel rail pressure that only gets worse when the engine is hot and stopped. Have you tried pulling the intake plumbing from the throttle body and shooting a short burst of starter fluid in? If you do, throw your intake plumbing quickly together and then the car starts on the first try - or at least suddenly seems like its going to - you can pretty much determine that your starting problem is fuel related. Your next steps may be checking the fuel rail pressure to see if you're having problems maintaining it after the car is stopped (the fuel rail pressure should not bleed down after the car's shut off). If its just not turning over, when you tried replacing the starter, did you try an aftermarket high-torque mini-starter instead of the weaker heat-soak-prone stockers? They tend to be a bit more resistant to problems.
Dwight
2016-01-22 05:51:52 UTC
I connect a small hot wire to to the power wire of my distrubetor, coming from choke of my eldebrock carb, in it burned up, now it doe have power on the dash board and it will not crank or turn over, could you tell me what should i check??
har n
2013-09-20 18:53:55 UTC
replace the erc and the bcm fuse and other fuses that are labelled to be related to fuel injection or ignition. replace them even if the look fine or even test to be good
2013-09-20 07:46:54 UTC
Plugs, plug wires, coil pack, or your fuel pump? No idea.. I'd have to be there to be any help.
2013-09-20 10:41:02 UTC
Call an elect. tech it might be the ing. switch at the column . Or call the dealer.


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