SHO resurrection: Cranks no start

[40BelowSummer]

Hey guys,

It's been a LONG time since I've turned a wrench on my 90 SHO. It's now time, but I've nearly forgotten more than I used to know these last ten years as it's been in storage for 6-7 years.

It cranks but won't start...
Fresh gas and I have spark and fuel pressure (maintains 22 psi when the fuel pump is run continuously).
I've checked some of the basics: no codes, spark plug wire order correct, intake grounded, vacuum lines look good, swapped DIS. My tach is spun around so unfortunately I cant tell if it's moving or not but like I said I do have spark. My driveway is on a huge incline or I'd try to push-start it.

I do have a TwEECer and I thought it could be the tune, so I started fresh with Josh's blower program and updated the MAF curve for my 90mm etc but no dice.

Any ideas or suggestions?

Also, I can't remember, is it normal for the CE light to stay on when @ KOEO?

 

[Devin]

CKS? I think you still get spark with a bad one.

 

[rubydist]

No, you get no spark with a bad crank sensor.

After you crank it for a while and it does not start, pull a plug - it should be soaked with gas. My guess is that you have fuel injectors that are gummed up and either not working at all, or are not putting enough fuel in the cylinder to allow it to start.

 

[sperold]

I would ensure the bolt that grounds the DIS is doing its job and double check the intake ground to the firewall lug.

Put in another cluster that has the tachometer working to see what is happening there. You have that 1 in 3 chance of it starting when the cam sensor is not identifying #1 cylinder, but usually you get it right after half a dozen attempts (at most).

Try a blast of atomized gas directly in the intake tubing to see if it could be a fuel issue. If it does not start with that, it is a spark issue, or a timing issue.

 

[40BelowSummer]

Yeah, I've cranked it many many times. I changed the cam sensor yesterday. The tach does move and I do have spark.
I'm hoping it is the crankshaft sensor at this point; I should have the new crank sensor in tonight.
The injectors should be good, probably 3000 miles on them total. I'll pull a plug to make sure fuel is making it in the cylinders.
The intake is grounded well. Even swapped the DIS. Will see how she does after the new CKS is in and buttoned up....

Also, I'm pretty sure it will start if push-started, I just can't test it right now due to a huge incline.
I recall having this issue last time it was on the road. It would push-start EVERY time but not start when cranked over.
Can anyone think of a correlation there? It was clear as night and day.

 

[luigisho]

Would it stay running if push started? If the crank sensor has failed then it should not run for long. That's the thing that leaves you stranded on the side of the road.

 

[black92]

Listen for an injector pulse. Or get a noid light to confirm the injectors are firing.

 

[40BelowSummer]

It would totally stay running before.
Last time I had it on the road I made a 1000 mile drive and every time I stopped it would crank and crank but fire up with the slightest push start every time. I did this at every gas station along the way. And it ran fine once started.

We’ll see how it does after I get this crank sensor in and I’ll make sure the injectors are working properly.
Thanks

 

[SHOdded]

Its always fun times replacing the CKS, what with making sure the gap is right and the wiring is routed properly!

 

[40BelowSummer]

Changed the crank/cam sensors. Have fuel pressure at the rail, have spark, have tach - but I'm not sure the injectors are firing... Pulled a plug and it looks dry. Pretty sure I dont hear the injector firing. Looking into a noid light...

 

[SHOdded]

Bad regulator? Pull the vacuum hose and see if there is fuel in that line? IDK if 22 psi is a sufficient pressure for FI operation, always thought mid 30's was needed.

 

[40BelowSummer]

Actually I did get the fuel pressure properly adjusted to 39 psi with the fuel pump on. This is on shonuts dual feed fpr setup so no stock regulator.

 

[sperold]

Did you try the 'Quick Start" or atomized gas directly in the intake tubing?

 

[40BelowSummer]

Did you try the 'Quick Start" or atomized gas directly in the intake tubing?

Like starting fluid? I haven't tried spraying anything in the intake/TB yet, I'm always hesitant to do that on thee cars, but may try that.

I also got a noid light to confirm if the injectors are pulsing/firing but it looks like I have to take the intake off before I can try that.

Although I'm sure it's fine, I have another X2J on the way. I'm also working on getting another CCRM

 

[black92]

You can make your own noid light for pennies instead of paying 20$ or more.

I made mine from a Taurus marker lamp. Soldered the ends, lightly hammered the flat to fit inside injector plug. Fyi, you do not need an led bulb which some research says you do.

 

[40BelowSummer]

I rented a noid kit. the only way I could get to the injector harness was removing the intake. turned the car over (with intake off) and nothing on the noid light.

 

[black92]

Reinstall the intake.

 

[40BelowSummer]

Reinstall the intake.

And plug in the noid light? Looks tight, I'll give it a shot

 

[black92]

Its been a few years since I did this, but I remember having the intake on. At least install the cross over tube to mount the dis

 

[40BelowSummer]

Thx Yeah, I dont know if I can hook up the noid with the intake on, it looks so tight to get to the injector harness