Car won't start

Sometimes you need to use computer from donor vehicle. Will the engine crank? Do you have a security system?

The engine won't crank. I changed every sensor on the engine and it is getting gas but no fire.

Are you saying there is no spark at the plugs?

Your security system will kill the starter and injector pulse.

I used the alarm keypad to unlock the doors but it still won't start. Both engines were running before I swapped them.

Was the engine out of the same year--make--model? The control system for the engine may not work, unless the computers are the same?

Check applicable trouble codes.

The engine came out of a 1996 Cadillac Sedan Deville.

The computers don't show to be the same. I don't think it will work.

I swapped every sensor on the engine. Is there any way to make it work?

Can you communicate with computer, check trouble codes? Can you get the computer from donor vehicle, don't know if everything will match-up, connectors, systems?

To check for codes, ignition on, press off and warmer buttons at the climate control center, at the same time. It should go into segment check, when it does release buttons, the codes should start to show up on the driver information center. Post the codes, me or somebody will talk to you.

Also, you can check the starter circuit at the starter, the purple wire at the starter solenoid S terminal should be hot with key in the crank position. If it isn't, you need to backtrack the circuit. Any testing at the starter, you need to make sure the tranny is in park or neutral and a functional e-brake is set.

It says P052, P109, i052, S036, S044, S060, S061, S062, and S070 all said history. P015, P055, T061 current. No ACP, No SIR, and PCM?.

The p015 and p055, I know what they are, shouldn't have any effect on your starter circuit. I can't find the T061, don't know? I'll look some more.

I gave you the wiring info on your starter circuit, did you check it?

It turns over. It just won't crank.

Cranking is starter action, so you saying it cranks good but won't start?

Engine cranking, do you have spark at the plugs and injector pulse? The po15 has to do with coolant temp sensor. The p055 has to do with throttle position sensor. I know you said you replaced all engine sensors, but, if the problem is on the wiring circuit somewhere, replacing parts won't fix it.

It does turn over good, it just won't start up. I checked the fire at each of the coils and neither one is firing.

Did you check for primary voltage at the ignition module. Check ground also. Take connector loose from ignition module, key on, no need to crank. Use a testlite between pink wire and black wire at the harness connector. If the lite comes on, voltage and ground should be ok.

I checked it with a voltmeter and it has 11.94 volts.

Same reading across battery posts? Some of the national brand autostores may be able to check ignition module for you. You can call and ask?

I called and none of them can check it.

Do an ohms test on crank sensors, 800--1200 ohms, if they both test ok, replace the ignition module, because I don't know what else to tell you. I hate to see you throw parts at,but, I've gone about as far as I can.

How do I test them?

You take the crank sensor connector loose from ignition module. Do an ohms test on the wiring terminals to the crank sensors.

If that checks out, with everything plugged into the ignition module. Turn the key on, at the ignition module, purple wire with white tracer is the 4x signal, should be 5 volts. The lite blue wire with black tracer is 24x signal, 5 volts.

Then, engine cranking, the 4x signal may go to 1.5--2volts. The 24x signal stays around 5 volts.

I got it to crank but it idles up and down.

Off idle, open the throttle, how does it sound? You may need to clean the idle air control valve and passages. You could have a vacuum leak? Other than idle, is it driveable?

I didn't check because it stay's idled up to about 4,000 RPM's. When I try to give it some gas, it doesn't respond. It runs like the throttle is completely open but it's not.

Take the throttle linkage loose, any difference? Block off the mouth of the throttle-body, any effect on the idle, that should kill it.

Check the tps and iac.

How did you get spark back?

Where is the iac valve located?

Look for an idle air control motor. If you answered some of my questions, it might help a little?

The two crankshaft position sensors were backwards. I had the plug to sensor A on sensor B.

Good catch.

I tried what you said but it still idles at about 4,000 RPM's.

When I cover the mouth of the throttle body completely, it still doesn't kill the motor and when I put it in gear, it idles at about 2,000 RPM,s.

I guess I'd have to look at it? If you block the air inlet, it shouldn't run, It has to have air. Does inlet air go to the mouth of throttle-body? If air inlet goes elsewhere, block it.

With engine off, unplug idle air motor. Start engine, idle any different? I'm about out of ideas?

It runs like you're on the gas at all times. It doesnt want to stop when you press the brake but as far as the transmission goes, it shifts perfect but it idles so high, I have to put it in neutral and turn it off.

Does the inlet air go to the throttle-body or elsewhere? I'm talking about the air inlet from the air filter, block it off. Did you unplug the idle air motor? Unplug the throttle positioner sensor. Do these one at a time with engine off, then start.

It goes to the throttle body on the intake. Unplugging the sensors doesn't change anything.

If the engine isn't getting air, it can't run. It's getting air from somewhere.

I did the thing again to check the codes and the only one that was current was P132

That is a knock sensor code. I don't think that will cause high-idle. I'd have to put a scanner on it, that will show live engine data, try to see what's going on.

You could try tapping the block close to knock sensor, see if any effect on idle?

I've seen faulty cruise controls go crazy and the rpms would hit the roof. If you had everything disconnected from throttle-body, that shouldn't be an issue.

What do you suggest I do?