Help please. Crank, no start

[Moy]

Hey all, I recently finished putting my engine back together, had to pull it for a rear main leak and figured to clean some other stuff up.

I can crank the engine over and over but it just won't catch.
-Brand new 7mgte harness
-Good ECU
-Rebuilt CPS by Halsupramk3 on here
-Mechanical timing set per TSRM
-CPS alignment set per TSRM
-Coilpack harness has acceptable resistance
-Brand new NGK coppers gapped to factory 0.8mm gap
-NGK plug wires less than 5k miles on them
-Ignition coils have acceptable resistance per TSRM

NO CODES

I know the injectors are firing cause I can smell gas out the tail pipe and also the plugs are wet after cranking. It'll sometimes want to catch but stumbles while cranking. If I block the throttle open (throttle past ~75-80% throttle deemed WOT, TPS disables fuel injectors for "clear flood" mode) while cranking, I get after-fires (popping from the muffler).

The only thing I'm weary of right now is the igniter. I checked the igniter per the TSRM, I have 12v at the appropriate terminal. I have 12v available at pin 1 on the coilpack harness at each of the ignition coils. I made a 3v tester to check for momentary continuity at pin 2 at each coil on the coilpack harness, but I'm not getting anything. I've tried two different igniters, both worked in the past, but now I'm not getting anything. The main harness was resistance checked between the igniter and coils and were within SAE specifications.

I'm stumped, and I need help. Any ideas would be very helpful at this point. I can get a video if necessary.

Thanks,
Chris

 

[supraguy@aol]

I say this in every thread that concerns a no-start situation, where the cps has been removed:
Even though you put it in as per the tsrm, it is very easy to be off one tooth, so i suggest the following; remove the adjustment bolt, and rotate the cps about a 1/4 inch past normal adjustment range, either direction. Try to start. If no success, rotate it the opposite direction, the same amount past the normal range, and again try to start. IF the cps is on the wrong tooth, this will identify the issue, and it requires hardly any investment of effort to rule this possibility out.

 

[Zrain25]

Agreed I had the the same issues when i I put my cps in it was off just a little bit when I put it in and it wouldn't start. It would try to start and stumble after a lot if cranking but no dice. I took it out and noticed it was off... Fired right up. I would try the cps agian. Like above u might be off just a tad

 

[Nick M]

If the CPS or igniter is not working right, then there will be no injection. If you have injection, the engine is out of time. That includes the CPS position.

 

[CajunKenny]

My money is on the CPS wires. Go give them a wiggle.

 

[GrimJack]

If you are getting fuel and spark - how did you check for spark, btw - then it's a timing issue. Verify the cam rotation against TDC on the crank - I've seen the belt slip a few teeth. Hell, I've seen the belt break, or the tensioner go, too.

 

[Nick M]

My money is on the CPS wires. Go give them a wiggle.

He won't have injection without the pickup. Then again, we don't really know that he has injection.

 

[Moy]

I'm smelling gas out of the tail pipe and the plugs are wet and smell like fuel. I've removed and reinstalled the timing belt and CPS about 4 times verifying every time that mechanical timing and CPS timing are in sync. I've rotated the CPS gear prior to installation both ways, and after instal have rotated the CPS. The engine harness is brand new, was still in the bag, new clips, new wires, still had the plastic covers over the ECU plugs (new old stock).
When bench-testing the CPS (DMM on mV connected to ground and pick-up pins), I get a signal (tested per TSRM, signal values in spec).

I checked spark by removing the plug boot for Cyl 1 and inserting a spark plug tester, grounded to a coilpack cover stud behind the upper rear timing cover, with a jumper wire connected from the stud to the negative terminal of the battery to ensure a solid ground. I cranked, and had no spark. Tried by removing boots for 1 and 6 and grounded both testers and had no spark on either as well.

The tach is getting signal as well while cranking, tach is "fluttering" while cranking. I'll take and post a video of it tomorrow.

(side note I have 2 AAS Degrees in auto repair, trained by ASE Master Techs, head of the department has a PhD in mechanical engineering focusing on automobiles). I've racked my brain, studied and double / triple checked everything through the TSRM on ignition and fuel delivery, and I'm still stumped. I've tried 2 different igniters, 2 different CPS's, 2 different ECUs, all worked before. Hence why I'm coming to you folks on the forum for advice.

 

[jetjock]

If you have no spark simply focus on that. Since you apparently have crank angle and rpm pulses along with injection just start at the ECU and signal trace the ignition system outward. What's so hard about that? And make sure the igniter is grounded.

 

[Moy]

Following the flowchart on pages FI-12 -- FI-13 in the TSRM:
Verified no DTC's.
Engine does not start with acc. pedal depressed.
No vacuum leaks.
Verified spark.
Verified spark plug gaps.
Verified fuel supply to injectors.
Ignition timing SHOULD be okay. Crank pulley match mark at 0*, cam gear match marks aligned with notches on upper rear timing cover. CPS inserted per TSRM.

EFI electronic circuit: AFM / Air temp. sensor verified working on a friends car. Water temp. sensor new. Wiring harness is brand spanking new. Have tried 2 different ECU's with same results. Injector resistor worked when I was running my GTE on GE electronics (pre-89 GE injectors are low impedance, injector resistor installed from factory)

On the flow chart, under the step "check spark plugs" (5th box from the top on page FI-12), it says
"-HINT-
Check compression pressure and valve clearance if necessary"

I'll check compression pressure tonight, but the valve clearance part? Will improper valve clearances cause so much cylinder leakage that there won't be enough compression for the engine to start?

 

[roadboy]

kinda long shot, but checked your fuses?

 

[Moy]

First thing I checked and all are good, but thank you.

 

[bioskyline]

the engine was running before you pulled it to fix the oil seal correct? id try diff plug wires and see, i have had issues with bad wires before

 

[mkiiichip]

Did you even read jj's post?

If you dont have spark, continuing on in the flow chart is pointless, as is checking compression.

Do you have any way of checking signals? Like injector pulse and coil signals? Smelling the exhaust doesn't count as verifying injector pulse.

 

[Moy]

Did you even read my last big post? I said I verified that I have spark.

Following the flowchart on pages FI-12 -- FI-13 in the TSRM:
Verified no DTC's.
Engine does not start with acc. pedal depressed.
No vacuum leaks.
Verified spark.
Verified spark plug gaps.
Verified fuel supply to injectors.

And if you're wondering how... Remove EFI fuse, disconnect plug wire from plug, insert spark tester into plug wire, ground spark tester, crank engine and observe tip for spark.

 

[suprra_girl]

I checked spark by removing the plug boot for Cyl 1 and inserting a spark plug tester, grounded to a coilpack cover stud behind the upper rear timing cover, with a jumper wire connected from the stud to the negative terminal of the battery to ensure a solid ground. I cranked, and had no spark. Tried by removing boots for 1 and 6 and grounded both testers and had no spark on either as well.

People are presuming you have no spark due to ^^

I had a similar problem recently, whether it's the same or not is a different story but turned out my fuel pump had started seizing and wasn't getting fuel up to the rail.

Pretty much if you have spark, fuel, air, then it should start.

Verify spark
Jumper the fuel pump FP and B+ at diagnostic connector turn ignition to on position, go and listen to the tank and the lines up at the rail, do you hear the fuel?
Get someone to crank the car (remove fuel pump jumper) and put a screwdriver onto the injector clips and put your ear to the screwdriver, do you hear the injectors clicking?
A very very common supra ailment is the cps plug, giving it a wiggle often throws the supra into life.
With the cps, set it per tsrm, line up the slot for the bolt hole centered and just slot it in straight and relaxed, the cps will naturally notch around but it will slot into tdc just fine, alot of people try to stop the cps notching around as they insert it which is where they start having cps alignment problems.

GL hope you get it sorted

 

[Nick M]

Pretty much if you have spark, fuel, air, then it should start.

Not if those events are out of time.

 

[jetjock]

Yet another thread where confusion reigns. I blame today's edgy sitcoms. Or diet soda. Or both...

 

[Nick M]

You mean it isn't Bush's fault?

 

[suprra_girl]

Not if those events are out of time.

True, I was going off the assumption that they had the timing right