smilekill

hello i have a 91 camaro rs and i just cant find whats making it not start i have put a new ignition coil in new distributor in new plugs and wires and set the timing where its ment to be but still no start. it seems like it is trying to start but just wont get there and im at a loss on what to do can someone please help me.

Schrade

See here...

vetteoz

iTrader: (13)

How do you know?

On a 4 stroke engine, # 1 cylinder comes to TDC twice ; on the compression and exhaust stroke.
Pick the wrong one and your dist will be 180 degrees out

Base91

iTrader: (1)

How was it running before you made the changes?

smilekill

it wasnt running at all

smilekill

im learning as i go so im not sure how to check the fuel pressure or know whats the leakdown time is but plugs are gaped.do i need the air filter on it for it to start i have a new filter for it? also i turned the motor by hand to get to the compression stroke.

Base91

iTrader: (1)

There's a schrader valve on top of the engine at the back. Take the cap off and a attach a fuel pressure gauge there. You can buy/rent/borrow one. However, if you turn on the key (but don't try to start it) you should hear the pump run for a second or two then stop. That means the fuel system is up to pressure. You still need to measure the pressure but the pump running then stopping is a good sign. A test you can try is to have someone turn the key to start the engine while you spray some starting fluid into the throttle body while you hold the throttle open. Be careful as it can backfire a bit. Have some wet rags at hand in case. If it fires and runs for a second or two it tells you you have compression, a spark at the right time but no fuel getting into the engine. Then you need to check the injectors which are the most likely source of the problem. Take off the upper plenum and test the resistance of each injector. They should all be high 12 ohms and all very close. If any is not close replace them all. Southbay on this board does a great set for about $125. And while you're at it replace the fuel pressure regulator diaphragm as you'll have the top off anyway. And do double check the distributor orientation and plug leads are in the correct order. There's more but that's a good next step. Do you have a manual? Chilton's has lots of good diagnostic steps you can follow.

vetteoz

iTrader: (13)

More info needed.
Is it kicking banging popping ,firing at all or is it just cranking over on the starter?

Before you do anything else confirm that the dist is set to TDC #1 cylinder on the COMPRESSION stroke

smilekill

it sound like its popping a little bit like a small amount of fuel is igniting and im pretty sure it is TDC but ill make sure it is

vetteoz

iTrader: (13)

Do you how to by using your finger on the spark plug hole?

smilekill

ya i know how to do that

Mrs.Crasher0083

Is it getting spark??? Can you see fuel spraying from the injectors.... we just had a problem with a no start......vetteoz helped out with that 1 .....we werent getting spark though. It turned out to be the ignition control module (37.99 @AZ). Maybe thats your problem????

ASE doc

The popping really sounds like timing 180 out. Good advice on verifying spark and injector spray. The TBI does not have a schrader valve. Checking pressure on the TBI is more involved and requires adapters to connect to the flare fittings. Listening for the pump to run is a good indication that there is fuel being supplied to the injectors. One thing to note about the 91 is that it is a VATS car. VATS Passkey prevents starting by interrupting the starter circuit and also by disabling injector pulse. The VATS module can fail so that while it allows the starter, it does not enable fuel.

You should be sure that you have injector pulse by testing with a 12 volt test light or a noid light. If you don't have injector pulse but you do have spark, there is a chance that your VATS module is not sending the fuel enable signal to the ECM. If no injector pulse, verify power to the injectors through the injector fuses before looking at the VATS or ECM circuits.

smilekill

ok so i did the fuel pressure test and i get 9 psi but when i turn the key off i lose pressure almost instantly.also i started testing in a few more times and im now getting random amounts of pressure and after i turn the motor over the pressure goes up to 10 im going to change the fuel filter and see if it helps

Base91

iTrader: (1)

When you take the filter off you could get a container under the open pipe and turn the key on for a second or so to see if the pump is pumping well. Do this before and after the filter. You could have a blockage further up from the filter.

smilekill

got the fuel filter changer with a lot of problems the fuel line broke on me it was rusted badly but got it fixed. Has good flow now but my battery dies so i have to get it charged and test ill let you guys know.

Richboll

I'm pretty sure that you wanted to replace that rusty fuel line anyway. By doing so you may have saved yourself some future heartache involving standing on the side of the road watching your pride and joy go up in flames.

Good job!