89 2500 5.7L another spark and fuel no start question, unfortunately.

[ben2go]

My son was driving his truck (89 2500 5.7L auto) last night. We were on the phone talking when the engine died like he turned the key off. He drifted off the road safely and put the truck in park. He tried to restart the truck. The engine started, but as soon as he put the truck in drive and pull away, it died. Since then, the engine spins with no issues but will not start. The ignition is giving bight blue spark on all 8 cylinders and the injectors are spraying a beautiful pattern against the throttle plates. It will not even sputter. What has been done to the truck over the last year. A full tune up by me, everything in the ignition system replaced except the module and coil. Distributor is tight and I set the timing by the service manual. Truck has ran flawlessly the last 10,000 to 15,000 miles, until last night. What I suspect are the ignition module, temp sensor, TPS, and oil pressure sensor. These are the things I know will stop a TBI engine from starting and running. I don't have an OBD I scan tool and I can't get one locally, I've tried. No shops are open in our small town or I'd just take it in. It's damned cold here and windy at the moment. Also, can't find any vacuum leaks. This truck has to go to work this evening. All I can do is throw parts at it and hope. Is there anything else I should look into?

 

[evilunclegrimace]

If you have spark I don't believe it is the ICM. You need to test spark with a spark tester that is designed to work with HEI.Try putting it in clear flood mode by holding the throttle pedal to the floor while cranking-do not pump the pedal.

Without a scanner it is going to take a lot of extra work to narrow down the cause of your no start.

Fuel pressure needs to be 9-13 PSI, a visual inspection is not a good indicator of proper pressure. A proper Fuel preessure tester is your best bet.

Is it turning over smoothly with out any variance in rpm like it has possibly jumped timing( not very likely but,,,).

Throw a commpession tester on a couple of cylinders to see if it has enough compression to fire the air fuel mix.

 

[ben2go]

Shop has had the truck for several days. They redid all of our work and scanned the PCM. Nothing, it still won't run for them. It's getting fuel and spark. No cats to be clogged. They removed the exhaust at the manifolds to check for a clogged muffler and nothing. Cam timing is spot on, ignition timing is spot on, fuel pressure is spot on, injectors are spraying a nice conical pattern as designed, compression is spot on, and still nothing. It won't even bark on ether. Everything in the ignition system has been changed again. They pulled and replaced the distributor. They replaced several sensors, senders, and relays. They bore scoped all the cylinders and everything looks fine. We're up to $1000 in repairs and labor, plus two $150 tows. My son and I have around $300-350 in parts thrown at it. The shop is even telling us to scrap the truck or convert it to carb. They think either the wiring harness is having an intermittent problem or the PCM is bad. They looked them up and can't get them from any of their suppliers. They refuse to try used parts because they're unsure if that is the problem. Used parts may make the problem even more difficult to diagnose further if they happen to be bad. The truck is a beater and not worth the $1700 we've already spent on it. We gave a $1000 for the truck in good running condition. We've kept up all the maintenance and have new tires and brakes on it. At this point, it's either carb swap or the crusher when they bring it in next month.

 

[evilunclegrimace]

How do you know that the iginition is "spot on " if the truck will not run? Rock auto has ECM's for your truck around $100 plus core.
If the shop has spent that much time and money on your truck and they can't make it run it is time to find a new shop to do buisness with.
What codes does the ECM show?
Does the check engine light work? will it flash a code 12 when the ALDL is jumpered?
Does the shop know how to force a trouble code to see if the ECM can even recognize a code?
WHICH sensors, senders and relays did they change and why?
What is the compression? and did they preform a leak down test?
If it will not start on ether I find it hard to believe that it has proper spark if the engine is in fact properly timed.
If you decide to scrap the truck let me know.

 

[ben2go]

ECM scans with no codes except O2 sensor and it was changed so that went away. CEL works and was on but O2 sensor took care of that. Yes, they've did stuff to check the ECM. I'm not sure what. The temp sensor, oil pressure, map, IAC, ignition module, coil, there was some others, but I can't remember the rest. We took the valve covers off and checked that everything was working properly. We set the crankshaft at TDC and everything was in time. Checked the distributor and the rotor was pointing at number one terminal. Pulled the dist to be sure the gear hadn't slipped and was still pinned to the shaft. All valves are moving. None are sticking open or closed. Compression was around 130 psi on all cylinders. The shop went through this themselves to confirm what I told them. Engine is a Jasper reman I helped PO install a few years before we bought the truck. The shop is reputable. They've helped me with many problems I couldn't diagnose. they're well known for fixing stuff other shops can't. This is a first for them as well. They're keeping the truck till Friday when we can get it towed to the crusher. They won't use retail suppliers for parts. I don't understand why, but it is what it is.

 

[evilunclegrimace]

Where are you at in the south east? It is a shame to crush a truck that can be fixed.

 

[GoToGuy]

Sending it to be scrapped is seriously poor judgement call. A decision you will regret in the long run.
There is no reason you can't get the OE service manual out , go to the diagnostic for " no start " conditions and just run the checklist from the beginning. If have a volt ohm meter you can do plenty of testing.
What have got to lose? You've invested in it, it's worth you time to start over recheck your work there is something you missed. Good luck.
PS. Are you using the factory OE service manual ?

 

[Komet]

Sorry buddy, this shop sucks and they took you for a ride. Now that it's been fully ejected from the parts cannon, I'd recommend attacking the problem from the opposite direction and get a datalog of what the ecm is thinking.

It would seem to be the case that something you believe to be true, is not true. Does it pop at all with starting fluid?

 

[Road Trip]

I'm with @GoToGuy and the others in here on this (unfortunate) situation you
find yourself in. Part of my belief system is that the right combo of Fuel + Spark + Compression =
it *has* to run.

I wish I was there to listen to the starter carefully. Wha-Wha-Wha-Wha-Wha-Wha-Wha-Wha
is the sound of all 8 cylinders giving healthy resistance to being turned over by the starter.

But Wheeeeeeeeeeeeeeeeeeeeee = no compression. (Timing chain jump, etc.) I'm dating myself,
but I can remember cars that suddenly stopped, still had spark & fuel delivery, but wouldn't run
thanks to the sudden shucking of the brittle nylon teeth on the factory cam gear. I'm not claiming
that this *has* to be what's ailing your machine -- just trying to emphasize that we need all
-3- in order to run.

IF the computer is still communicating with your scan tool, then it should be running enough to help
figure out what's gone wrong. Suddenly shutting off for no reason can be electrical, fuel delivery,
or even a mechanical failure. If you are willing to post video(s) of engine behavior and follow the
FSM 'No Start' Troubleshooting flows, I really think that this can be sorted out between the all of us.

Give it some thought before scrapping it.

 

[ben2go]

Guys, the truck was wrecked when we bought it. It's full of rust. The power windows and locks don't work. Every window leaks. It was a true beater just waiting for the day to put it out of it's misery. I handed over the title to the crusher operator at 4 pm this afternoon. It's a done deal.