Help! I keep getting ALMOST stranded. Starting issue!!!

[Jdesign]

Solved!!!!!

Hello all!! I have a 93 vert with the stock m20b25 in it. My car only has about 112k on it. Recently I have had starting issues. The car will crank over no problem but wont fire. I haven't had a second person around to help me check for spark so that may be the issue but hear me out first because it will start and run.

So far the car has started every time but it is taking a long time(30sec-4min) sometimes and I am getting worried soon it wont start at all. Its more difficult to start when the car is cold and has been sitting. Once it starts it runs and drives perfectly fine. If I shut it off its a 40/60 chance of it starting right back up again.

1.I have read that the temp sensor can fail and cause fuel air mix issues. Is this the case I am having?

2.My Second guess would be that the fuel pump is failing or the relay for the pump. Where are these relays and how can I check them?

3.Are my injectors are clogged?I understand that the issue could be fouled injectors too, which I plan on cleaning tonight.

4.Now yesterday was the first time I have had a new issue and I am not sure if it is related or not. I was stopped just letting the car idle and it suddenly r3ved to about 1800 RPM and then back to idle. It was really odd and out of place. This lead me to think my idle control valve is the problem(but I cleaned it or I have a vaccumm leak? I can Smoke test the car but not until this weekend.


Please help me out guys. Am I looking in the right direction? Has anyone had similar issues in the past?

So far I have replaced the following engine parts. Some may or may not be related to this problem but I figured its worth adding:

-spark plus
-cap and rotor
-timing belt and all the other belts and seals that go along with it
-valve cover gasket
-oil pan gasket
-water pump
-water pump gasket
-thermostat gasket
-thermostat
-fuel filter
-air filter

Any input would be greatly appreciated fellow enthusiasts!

[603Racing]

Fuel pressure or vacuum leaks are likely the cause. It could be spark and that is easy enough to check, and you should.

Check your fuel pressure by T-ing a gauge into the fuel supply line just before the fuel rail. Check your Fuel Pressure Regulator. A bad FPR can sometimes be detected by pulling the vacuum line that runs form the FPR to the intake. If it has raw fuel in it then you know the FPR is bad. You can also check the fuel return line coming out of the FPR to ensure it is letting fuel through.

Get a smoke test, that will give you a difinitive answer on vacuum leaks.

Doesn't sound like a temp sensor issue. Doesn't sound like a relay issue. Doesn't sound like clogged injectors. It could be one of these, but I doubt it.

As for the 1800 rev at idle, I'd chalk that up to a symptom of what is causing your hard/no start.

Check the items mentioned (other members may have good ideas on other easy/cheap things to check) above before you throw a bunch of parts at it.

[Jdesign]

Awesome!!! Thank you a lot!!! I just needed an idea on where to start. I will look into fuel issues tonight and if I don't find the problem I will move onto vacuum leaks and a smoke test this weekend.

[FLG]

Also be sure to check and clean your grounds. There is one on the strut tower passenger side, and one o the driver side from the oil pan to the frame rail

[603Racing]

Also be sure to check and clean your grounds. There is one on the strut tower passenger side, and one o the driver side from the oil pan to the frame rail

+1 ^

Yes, good idea. There is also a ground behind the rear seat back on the drive side near the door panel. If memory serves me this contains the ground for the fuel pump.

[Jdesign]

Well guys, I checked for spark this after noon when it happened again. And what do you know, no spark...... I am guessing bad coil? I also just read that the Crank Position Sensor (CPS) can commonly fail.

[FLG]

Could be coil, bad ground, bad/weak cps.

Could check the resistance on the cps, should be around 540ish

Sent from my Galaxy Nexus using Tapatalk 2

[Jdesign]

Do you know what the resistance off of the coil should be by any chance?

[FLG]

Primary 0.5 secondary 5k

Edited..

Sent from my Galaxy Nexus using Tapatalk 2

[Jdesign]

Just checked the coil and the CPS. Both tested fine. What gives?

[Jdesign]

I was still convinced my CPS was bad so I pulled it out and took another reading and cleaned it. For some reason the resistance between pin 1 and 2 climbs slowly and doesn't stop?? I assume it's bad so I have a new one on order.

Another thing I saw, was someone having issues with the coolant temp sensor. Is that possible?

[603Racing]

C191 plug, check for corrosion.

[Jdesign]

someone PM'd me about checking that. They stated:

Also be sure to check connector c191 under the intake manifold. Moisture or corrosion could be causing issues. Sensors and injectors share this connector for signal path. If sensors checkout then this connector could be the issue.

It's about an 1 1/2" round and right under the intake manifold/throttle body. You might have to remove the AFM and hose to the throttle body to get clear access.

I guess we did just get a shit load of rain, so I plan on giving this a shot tonight. Thanks for everyone's advice so far!

[Jdesign]

Just checked the c191. Looks like new, no corrosion. What's next?

[ak-]

Your car will still start with a bad temp sensor, so I'd rule that out.