My engine cranks but will not start?

Welcome to 2CarPros.

Do me a favor, see if it will start for a couple seconds using starting fluid. If it does,. then we know it is a fuel related issue. Since you have spark, either it is fuel related or something internal has failed.

As far as the noise, is it the starter making the noise or the engine itself? You have me questioning of it is a timing belt issue. If it is a belt or timing issue, it won't start with starting fluid and we will need to confirm timing by performing a compression test.

The good news is that this isn't an interference engine, so no damage would have happened if the belt broke or jumped.

Here is a link you may find helpful. Also, if it is possible, record the engine cranking and upload it so I can hear what is happening.

https://www.2carpros.com/articles/car-cranks-but-wont-start

Let me know what happens.

Take care,
Joe

it was the crankshaft angle sensor, I got a new one started right up thank you.

my Daughter drove the trooper to the store came home and shut if off. Wouldn't restart. Good spark. Starts and runs very briefly with Starting fluid. Replaced Fuel pump. Fuses test ok. No fuel to filter. No sound from fuel pump. What to test next? I assume there's no voltage to the pump but I do have voltage to the fuses.

Hi TWBartlett,

Thanks for the donation.

I suspect the fuel pump relay in under hood fuse box is not working to supply power to the pump.

It gets its main power from the FL-3 ECM fuse (30A) and goes to the F10 fuel pump fuse (15A) which leads to the fuel pump.

I found the problem. The connection inside the tank from the sending unit to the pump had burnt and was open.

Turn key on everything comes on turn key and makes doing sound then nothing.

Hello,

This could be a problem with your vehicle's Crankshaft Position Sensor (CKP). Your vehicle uses the information from the CKP to determine the rotational speed of the crankshaft for ignition timing. If your vehicle's Power-train Control Module (PCM) does not get this signal it will not spark the spark plugs and your vehicle will not start. I have included a few links below for you to go to.

https://www.2carpros.com/articles/how-a-crank-shaft-angle-sensor-works
https://www.2carpros.com/articles/symptoms-of-a-bad-crankshaft-sensor
https://www.2carpros.com/articles/crankshaft-angle-sensor-replacement

I have also included in the diagrams down below the information on the location of the CKP for your vehicle. Please go through these guides and get to us with what you are able to find out.

Thanks,
Alex
2CarPros

If this sensor is out should I replace the other sensors too?

Hello again,

No, not necessarily. Usually they don't tend to fail all as a collective unit, but individually with no rhyme or reason to their failures. I go by the adage "don't fix what isn't broken", but that's just me. If you would like to replace the other sensors in your engine I will more than happy to provide you with a list and instructions to replace them on your vehicle. Please let us know what you want to do and how everything turns out.

Thanks,
Alex
2CarPros

2001 Isuzu Trooper mileage 128,000 My Trooper failed to start today after driving regularly. I think it may have slipped time. When trying to start it popped and ran for a couple of seconds very roughly then died. Now it will not make any sound as if trying to start. While turning the engine over, I took the oil filler cap off while putting my hand over the opening. It was blowing quite a bit. I think I have heard that is a symptom. What do you think? I went back into town to retrieve the Trooper this AM and it started right up. I drove nine miles home and it started sputtering and died in the driveway. It will not start now. I took the fuel line off above the injector and the line had lots of pressure. I cranked with the line off but no fuel came out. Any thoughts?

Perform a compression check on the engine. If all four cylinders are low (below 100) the timing belt has probably failed. Check for spark at the spark plugs. If spark is present at the plugs, check for 12 volts at the fuel pump. Scan computer with an engine scanner and check for trouble codes.

My Trooper will not start; the engine cranks over; the fuel pump works and fuel flows thru the filter to the engine; the vehicle has an alarm system and I replaced the batteries for the remote after this problem appeared; I have also cycled the Auto trans shifter; the engine does crank over but fails to run in both park and neutral.

Hi Joe Errante,

Thank you for the donation.

When engine fails to start, it could either be due to lack of sparks due to ignition fault, fuel supply or engine mechanical. You would need to find out what is missing causing the problem.

Since fuel delivery has been checked and seems to be working, you might need to test the fuel pressure and the workings of the injectors.

We have comprehensive testing procedures outlined in the link below. Go through them and if you require further assistance, just post reply to this post and I will get back to you.

Have had this since it was at about 160K. Check engine light always on. Temporarily fixed when dealt with a clogged egr valve. Has always had extremely strong gas fumes, especially in hot weather. Occasionally have issues in hot weather with slow/no acceleration then when it jumps forward and rpms drop, slow acceleration again. Now having issue of it not starting off and on. Leaning towards an issue with a connection from the ecu to throttle body or a short in wires but unable to find a wiring diagram to identify exactly which wires to focus on. Any help is appreciated.

First have codes read then post will advise

Will do. I know in the past there was a P0140 for an exhaust recirculation issue and one for a random misfire.
In the meantime, are you able to provide a copy of the electrical wiring diagram showing the ecu and throttle body connections?

140 is faulty HO2S no.2 bank 1 most likely chaffed wiring but if light on constant then O2 may need replacing. this will cause gas smell and other issues

What is the best way to check the sensors? I have a diagram showing the location of all 4 sensors (its for a 2002 but i don't imagine there's much difference). Do you have any rough idea of what the sensors cost? Wondering if it would be worth just replacing all 4 and seeing if that makes any difference. Would faulty 02sensor by any chance cause the issue of it not wanting to start? A mechanic also suggested checking the evap canister - haven't done that yet as until we had the diagram, we couldn't find it. It's not where we thought it should be.

I was able to get codes. Hope these help point us in the right direction. there were 13 total: P0420, P0401, P1404, P0402, P1125, P1295, P1340, P0300, P0137, P0420P, P1404P, P0402P, P0300P.

Way too ,many codes try this clear all codes then runn recheck see what resets

For me sounds like it needs reflashing all those codes