1990 22re pickup - has always started, drove it to the grocery Store about 5-10 minutes from home, parked and shopped for 20 min. Would not start when I tried to leave.

Cranks over fine, and did so for about 10 seconds, maybe 5 times. Looked under the hood and all I could find was 1 spark plug wire had come off almost all of the way.
Continues to crank but not start. Fuel was close to E so added 1 gallon but still no start.

Hesitant to post the trucks history as I don’t want to complicate any suggestions on where to start troubleshooting… but here is some anyways

Rebuilt the engine about 10k miles ago. It was running good when this was done, just did it all while I was doing a timing chain and it’s components.

New pistons/rods/bearings(LCE) machine shop decked the block and head and tested for leaks. New standard crank.
All new head gasket and other gaskets, new valves lapped in and springs. Bored 20 over with pistons to match. New TPS, water temp sensor, oem plugs/distributor/wires and much more. Truck has been running okay since, aside from the described below and the top end loud ticking (reused same camshaft and rocker arms)
It always had a hesitation anything below about 3k rpm’s and then would take off like a bat out of hell. This problem carried over to the new rebuild and slowly got worse along with some stumbling at idle when hot, and exaust smelled like burnt gun powder when coming to a stop (all new exaust from LCE)

-Tried to troubleshoot this issue by unplugging the new denso oxygen sensor which is installed just downstream from the new cat…. No change
-Tried blocking off EGR with a strip cut from a tin can… No change
-Tried unplugging cold start injector…. No change
-Tried replacing temperature sensor (not the one for the gauge on dash, the one the computer reads)…. No change


Some side notes ——
I can hear an exaust leak probably somewhere between the header and the cat, recently re-adjusted the new TPS, recently took the afm out and tested it and cleaned.. wasn’t very dirty at all (not good with a multi meter but do believe one of the readings was reading too high but not sure)


Yes I rebuilt the engine and was pretty detail oriented but I am still a novice when it comes to troubleshooting sensors, using multi meters etc and get confused easily while trying.

If someone more experienced can help guide me on what steps to take and in what order with possibly some details of each step, I’d be super appreciative.
Need this truck for work the day after tomorrow and am stressing.

thanks for reading!

 

See if it has spark by having someone crank it while you hold the coil wire near ground and see if you get spark.

Also see if you have fuel. Can you hear the pump running? You can either loosen the cold start injector to look for fuel or pull the return hose at the hardline near the firewall.

That's two basic checks to get you started troubleshooting.

Loud ticking? Valve adjustment? I've "heard" sometimes the rockers can hit the rocker cover if bolted down too tight. Never experienced it myself. Worth a look I guess.

It will usually still run with an exhaust leak.

The fuel pump is supposed to come on for a few seconds when you crank it over and stay on once it gets a signal from the AFM.

You can jump the fuel pump to bypass at the small diagnostic box with the flip up cover. A wire or paperclip between FP and Bat+

Once you get it running again, check your valve lash, timing, TPS and make sure no vacuum leaks. Fix your exhaust leak too.

Any blown fuses?

Check engine light?

Good luck.

 

Im about to go out and start troubleshooting, I will confirm what you replied and let you know the results.

The loud ticking has been there since before the rebuild, have tried multiple valve adjustments.. cold/hot 8/12 and 7/11 and it’s just loud.
the rocker arms may be hitting the cover some but that’s not the bull of the ticking noise I’m hearing. Thinking either worm camshaft or rocker arm (can’t see any flat spots etc but maybe)
Ive heard that the arms in the rocker shaft assembly can get bent from someone over torquing the valve cover nuts, making it impossible to get an accurate valve adjustment, but no way to tell if that’s the case.

It seems to be somewhere around one of the back sets of valves but can’t pinpoint. Plan to get new rocker arm assembly and camshaft at some point if I can get the hesitation and low power when hot issue fixed (after figuring out the no run issue)

I couldn’t not find any blown fuses but not sure how to test any of the big block fuses (forget what they’re called.. maybe relays?)
I did not have any check engine light until I unplugged the O2 sensor
i did have a code for I believe the TPS before any of this happened when trying to diagnose the low power when hot and hesitation below 3k rpm’s, but have adjusted the TPS many times per spec with no change in this issue.

Gonna go test spark, check fuel at cold start injector, if no fuel jump the diag and see if the pump comes on, will report back in a couple hours.

thanks!

 

I started by checking fuel. And think I’ve found an issue. I can hear a slight noise at the pump when jumping those 2 terminals inside the diag port. But when I crack the cold start injector banjos bolt, I get zero fuel spray. Just 2 days ago I cracked this open and fuel sprayed out for 20 seconds or so until the pressure let out.
What do you recommend i do next. Unsure what components to test that could cause this or how to confirm the pump isn’t working properly.

any tips for this?

 

If the pump doesn't pump with the Fp and B+ pins in the diag port jumped, and the key on, either the pump itself, or the wiring to it, are bad. Note that the connections for the wires, on top of the plate the pump hangs from, are known for developing corrosion. You can check to see if you have +12 VDC on one of them, with the jumper in, and the key on. If you do, and no fuel, or no sound of the fuel pump, check the connections for corrosion build up. If they are both clean and shiney, bad pump. You can unscrew the plate, and actually pysically check if the pump runs. Or submerge it into a container and test to see if the level drops at all. Also, check the "sock" on the bottom of the pump. If it's clogged, no fuel flow, even if the pump runs.
Bear in mind the pump is cooled by the fuel it's submerged in, so do NOT run it for more than a second or two unless it's submerged. Also, do NOT test it in anything other than fuel. Never use water, or anything like that. Remember the flammability of fuel, and be VERY careful around it! Always have an observer, and a good ABC fire extinguisher on hand.

You can also start testing for fuel farther back along the fuel supply system's hoses. Check at the input to the pulsation damper, the entrance to the fuel filter, the output of the pump on the hanger plate. If you have fuel at one of those, but not past them, obviously, the item is clogged. Or the hoses going to it.

Hope this is some small help...
Pat☺

 

Thanks man for the help! The fuel pump was making noise when I jumped those terminals but I was getting no flow to the cold start injector. Put a new pump in and it fired right up.
Still dealing with the issue of stumbling idle when hot and hesitation described above. Cannot seem to figure it out. Any ideas on that?

I decided after fixing the fuel pump I’d tackle replacing the front end center link that had almost completely dropped the end shafts out of itself.
Gotta rent a tool to get the last 2 stuck joints out of it.
Ordered both sets of OEM inner and outer tie rod ends after seeing their condition.

Love my 30+ year old truck but she’s showing her age lately.

 

Posting this in case someone else stumbles on this thread and did what I did.
Just happened to read something that made me realize when I installed my full front to back exaust system from LCE, I mounted my denso oxygen sensor just downstream from the cat. I’m now to believe it’s supposed to be mounted just upstream from the cat.
So basically my O2 sensor is reading the amount of fuel in the exaust after the cat has already burned most of it off.. telling the computer it’s running lean and adding more fuel.
Makes sense why I’ve been smelling burnt gun powder as the cats been burning excess fuel and running rich.

Now I’m wondering… since I’ve probably toasted my cat by now, is it worth replacing when I have the local shop redo my exaust from the header back? Or does it really matter. What is your opinion? Thanks