Did a cam/ heads install; turns over but won't start

1FSTBRD

Registered User
I did a cam/ heads install on my Mustang a couple of months ago, no problems (other than a erratic/ hunting idle that was solved by raising the idle). Here, I'm a bit stumped, because the car had no issues before the teardown. I think that it may have something to do with fuel or spark (or a huge air leak somewhere), seeing as the car turns over, but won't start. It's plug and pray, all the way. :D I've seemingly checked all connectors, connections and hoses, and have also wrote a tune from Dave D to my QH for my mods, and QH/ BE seem to be reading everything fine now, after I had some trouble in the last week trying to get the hang of it.

Here's what I've done:

--tightened the heads down to factory specs
--lined the crankshaft timing mark up with the camshaft timing mark (keyways), and put a new timing chain and tensioner on it from Cloyes
--I've torn down/ re-installed the TB/ intake plenum/ supercharger/ return plenum/ intercooling tubes two times before and had made sure that I had hooked up and tightened everything just like I had back then, including gasket maker stuff on all of the intercooler tubing connectors. There was one time that I hadn't tightened the sc top collar nut enough, and the car would start and fire up, but die down right away or idle like crap, and another time, the lower intercooler tube wasn't lined up 100 percent with the intercooler. Same effect; would start, but die right away from no vacuum. So I'm thinking that I can rule that out, because the car should at least fire up, correct?
--the DIS worked fine before the teardown
--I have re-checked all of the spark plug wires at both the spark plugs and coil pack. Everything looks like it is correct
--I'd put the original coil pack on (was otherwise running a Screamin' Demon), and had also made sure that the grounding capacitor was bolted to one of the coil pack bolts, and had re-checked the coil pack electrical connector
--re checked crankshaft sensor; appears to be correct
--set up the camshaft sensor and housing to Ford specs at 26 degrees past TDC on cylinder 1 on the compression stroke (notch in crankshaft lined up with pointer on the block), with (for lack of a better description without posting the official Ford diagram) the sensor essentially pointing to the passenger side headlight (fairly easy to judge, since moving the camshaft position housing gear a notch forward or backwards puts the angle way off); bought a camshaft sensor tool to line it up instead of eyeballing/ ballparking it
--cycled the key on and off several times to prime the fuel pump; I can hear it turn on
--checked the fuel pump reset button in the trunk, just in case it was tripped. It wasn't.
--the battery was toast after sitting for a month with the alarm on (this also drained my Mustang battery and I had to boost it, and it was similarly hesitant to fire up on first start after the install). Wasn't holding a charge, as it would read 12.25 V with an ohmmeter with no accessories on, and would drop to 11.7 immediately with the accessories turned on. Tried to charge it and it still dropped to 9.77 volts on cranking. I had bought a new battery and put it in and it will still crank but not start
--double checked the injector electrical wiring; the wiring has a tag for #1 injector, and from there on out, it's pretty much straightforward, since the wiring harness has short wires for the injectors that (should) make it obvious as to which one goes which
--O2 sensors are hooked up (the only one that I disconnected was the driver's side, and that is definetely re-connected)
--tested all fuses, and they are fine. The fusible link fuses I didn't test yet, though, but visually, none of them seem to be fried

I double checked all the connections for the obvious things--MAF, throttle body (position sensor connector, IAC connector), and all the vacuum connections on the plenums.

One thing I need to clarify is that I had bought some 42 lb injectors from Super Coupe Performance. Not sure what brand they are; just that they're the ones that Bill sells on his site. One thing that I noticed, is that they don't sit in the injector hole like the factory ones do.......there's no "hat" on the injector, where it seats it in there nicely. I had pushed the injectors in as far as they'd go without forcing them, and they seemed snug. Could the problem lie here?

Also, there are two connectors that appear to have no other connection to go to:

--one is a grey connector behind the intake/ return plenum, and appears to have been not connected when I bought the car. My SC is a '91 with an '89 engine, and I'm wondering if this wasn't for something like an EGR. Trying to eliminate problems here, I'd looked at the inside of where the connection would be, and it is dusty, much like everything else along the firewall. You'd think that if it was hooked up, there would be a clear line from where the dusty outer part would be, to a clean and non-dusty one. I don't remember ever disconnecting this; it was hidden down the firewall almost down by the transmission/ engine connection
--one is branching off right from where the DMM sensor for the windshield washer reservoir is. It too, appears like there is no connection for it to go to. I checked all the adjacent wires around it; found nothing. Thought it may have been the power steering, but it is hooked up. Thought it may have been from the power box or something, but to no avail. It has a layer of oil on the outside of it, and I checked the inner part of where it would have been not exposed to that layer of oil, and it has the same layer on it, which would seem to indicate that it was never hooked up to anything and could have been something that was wired up for a '91 instead of an '89

The only other thing that I did was to delete the A/C and all the hoses and run a dummy pulley (cut off two ribs), but I wouldn't think that would affect anything?

Edit: you know, it's probably gonna be something small and overlooked. :D
 
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Mine split a clots timing set in half because I didn't put the spacer that goes on the end of the cam between it and the thrust plate. I hope that's not your issue.
 
Mine split a clots timing set in half because I didn't put the spacer that goes on the end of the cam between it and the thrust plate. I hope that's not your issue.

By the spacer, do you mean the gear that drives the camshaft position synchronizer? I'd definetely put that on.
 
Good evening


I would check the following:

--The two large main engine harness at the firewall next to the A/C accumulator. Check connector for the tightness and security.

--DIS harness connectors for brittle/expose wiring. Re-check the connector from the DIS harness to the crank sensor. I've had that connector not "snap-lock" causing a engine crank but not start. The cause was from debris in the connector.

--The harmonic balancer. One condition of a soon to fail 1989-1993 types unit is vane "witness" or striking marks at the sensor gap. This condition over a period of time will cause the crank sensor to fail.

--Visually check the fuel rail. Look specifically if the fuel rail has not been rebuilt at the "U" bend at the fuel pressure regulator and the front where it routed at the intake manifold for "pinch" restriction especially with the description of the updated fuel injectors. Do a fuel pressure test.

--Check the four DIS mount threaded bores for damage, obstruction and or rust. One of the bolts provide a ground for DIS operation.

As for the connector questions.

--According this site FAQ this is the list of cars with EGR. http://www.sccoa.com/forums/showthread.php?12482-What-year-Super-Coupes-had-the-EGR-valve
It look as if this is EGR connector you found.


--The second connector in question might be for the windshield wiper tank pump. Is it the odd two cavity connector?


Good Luck.
 
Good evening


I would check the following:

--The two large main engine harness at the firewall next to the A/C accumulator. Check connector for the tightness and security.

--DIS harness connectors for brittle/expose wiring. Re-check the connector from the DIS harness to the crank sensor. I've had that connector not "snap-lock" causing a engine crank but not start. The cause was from debris in the connector.

--The harmonic balancer. One condition of a soon to fail 1989-1993 types unit is vane "witness" or striking marks at the sensor gap. This condition over a period of time will cause the crank sensor to fail.

--Visually check the fuel rail. Look specifically if the fuel rail has not been rebuilt at the "U" bend at the fuel pressure regulator and the front where it routed at the intake manifold for "pinch" restriction especially with the description of the updated fuel injectors. Do a fuel pressure test.

--Check the four DIS mount threaded bores for damage, obstruction and or rust. One of the bolts provide a ground for DIS operation.

As for the connector questions.

--According this site FAQ this is the list of cars with EGR. http://www.sccoa.com/forums/showthread.php?12482-What-year-Super-Coupes-had-the-EGR-valve
It look as if this is EGR connector you found.


--The second connector in question might be for the windshield wiper tank pump. Is it the odd two cavity connector?


Good Luck.

Hi Sam, you list some good things to check!

I'm definetely going to take some electrical connector spray that I have, and clean out all of the the contacts, just to be sure. I did leave the harness in the engine bay during teardown and install, and that would have gave dirt and dust an opportunity to get in there. It looks like someone had spliced in a couple of the DIS wires before I had got the car.

The second connector is coming out of the same wiring area as the windshield wiper tank pump. I had made sure the pump was connected (it certainly is an odd two cavity connector that appears to be the only connector like that). The connector that isn't connected looks to be about the size and relative similarity to the throttle position sensor connector.....a smaller type.
 
Found the problem--crank sensor. It must have been hitting the balancer vanes somehow, and it is visibly damaged. I'm going to pick up a Powerbond balancer, too, since I should have really put one on to begin with. This is fate saying "do this now". :D
 
By the spacer, do you mean the gear that drives the camshaft position synchronizer? I'd definetely put that on.
No I'm talking about the spacer that goes on the end of the cam and fits inside the thrust plate. It keeps the cam from walking front to back
 
I had replaced the damaged crank sensor.......still no start. I checked the spark plug in cylinder # 1, and it was wet from fuel, so I'm getting fuel. On the Quarterhorse, out of the things that would register on the datalog (load, air temperature, spark, mph), there was no spark registering, it stayed at 0. Load went to 200. Could this be a DIS problem? I had checked ALL wires, and had cleaned the connectors with electrical spray, and still nothing. I'd cleaned the bolts on the DIS, in case it was a grounding problem as Sam speculated, and it still wouldn't start.

How do you check for a bad DIS? Everything seems to point to it, but it would be weird if it just coincidentally decided to crap out right during my cam/ heads install.
 
Good morning


Baring any problems with the DIS or the tune there is a unique issue (at least to me) that you may want to check. There could be harmonic balancer vane interference at the crank sensor gap.

I've had the problem with a Dorman and a PowerBond unit. On the Dorman there was a tapping noise like a lifter. Eventually the car stumbled and died. The crank sensor required

replacement after the bracket modification.

With the PowerBond unit the car would not start until the after the bracket modification.

It appears sometimes the new balancer vanes are slightly wider than the original Ford unit and does not provide enough clearance between at the crank sensor gap. You can see this when the

front of the car is on jacks and you rotate the balancer while looking at the vane/crank sensor gap. The vane should not touch the sensor and or mount bracket.

You a verify by removing the crank sensor/mount bracket assembly and inspect for semi-circular grove in direct path of the crank sensor gap path.

Re-torque the balance bolt.

Use a large file and remove enough material at the bracket mount "pad" to establish clearance. Might take a coupe of trial fitting to get it right.


Good Luck.
 
Hi Sam, you may be onto something--when I took installed the Powerbond balancer yesterday and the new crank sensor and then disassembled everything to look at the timing chain marks to again double check that they were lined up with the marks/ keyways/ TDC on the compression stroke (arggghhh! And also to make sure that the timing chain hadn't snapped like davec73 mentioned), I had noticed that there was a groove in the sensor plastic, where the vanes had contacted it.
 
I had found this link in the thread that you had posted, Sam:

http://mnharms.com/tutorials/disnostart/

This is exactly what I was after! It will narrow down the problem.

Edit: tested the power wire of the crank sensor (red with light green stripe) with the other lead going to the negative post on the battery while I cranked the motor over, and it was getting lots of voltage on the multimeter and would register multiple times within a cranking rotation (like the troubleshooting says--they mention use of a test light, but in this case, I read the voltage). Does this mean that the crank sensor can be ruled out, or if the vanes are still hitting the plastic in the crank sensor gap, would this still throw the whole system off? I noticed that the crank sensor was reading 10-11V or so......does it need to be at the full 12V or more?

The smoking gun seems to be N18 in that troubleshooting list.....everything before that checks out fine, but it's when I disconnect the coil pack and turn the engine to on that there's no signal at the dis wires on pins 8,9 and 11. This is with both the engine off and on, but when I hook the coil pack harness connector back up, the signal is there. Looks like DIS be the problem. :D
 
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Good afternoon

I could be wrong but looking at the step 18 of the checklist you should not get a LED or volt reading with the ignition coil connector disconnected. If there is a reading with the ignition coil connector disconnected replace the harness or DIS. Disconnecting the ignition coil connector will cause a engine crank but no start condition. I would be interested in step N 25 of the test.

Good Luck.
 
Good afternoon

I could be wrong but looking at the step 18 of the checklist you should not get a LED or volt reading with the ignition coil connector disconnected. If there is a reading with the ignition coil connector disconnected replace the harness or DIS. Disconnecting the ignition coil connector will cause a engine crank but no start condition. I would be interested in step N 25 of the test.

Good Luck.

The way that I read step 18 is basically if you get a reading at all with the coil pack disconnected, it's the wiring or harness/ connectors. If there's no reading, then it's the DIS.
 
I replaced the DIS (bought a new one, just to have a spare one on hand), and still no start. Though, Sam, like you mention with the crankshaft sensor, even after adjusting it, there was clearly a fair bit of contact from the vanes with the plastic. I'm going to remove some material from the bolt pedestals on the back of the crankshaft sensor bracket and re-position it.
 
I've put dozens of hours into troubleshooting this crap, and it's wearing thin on me. I've:


--bought another crank sensor (just in case the new one was bad). Filed down the back pedestals of the crank sensor bracket. Re-adjusted the crank sensor so that the vanes aren't hitting it. No luck.
--checked and probed each and every wire in the harness, twice. In the mnharms troubleshooting, I always get to N18, with the test lamp being on, saying "check the connectors and service or replace the harness". I've even checked the ends of the connectors, with a continuity tester, to the wires just before the connector. Everything has continuity. I fear if I buy a new harness, it's not going to have better results, because all the wires have continuity
--bought a new DIS
--rechecked all the grounds in the harness
--tested the ground from the block to the battery (disconnected the battery, with a probe from the negative terminal to the battery cable)
--have two working spare coil packs for a while, and no start

The car still feels like it's not getting spark--it's getting fuel and has compression, but just has no "oomph" to start it. Starter seems to be fine, but even when I jump the car, it feels like it's not accepting a boost for some reason.
 
Good evening


Sorry about start issue. Take a look at the spark plug(s) and see if they are wet. Could be that with all the start attempts the cylinders are "flooded." As I understand engine cold crank - "strategy" the EEC injectors are "fired" once during two crankshaft revolutions and starts a timer. After 20 seconds, if the engine has not fired, the EEC reduces injector pulse times to prevent flooding. Try clearing the cylinders by cranking with the accelerator to the floor. Wide open throttle TPS signal cuts off fuel injection so the incoming air can sweep out some of the raw fuel and dilute the rest enough to fire. May take a few times. Worth a try.



Good Luck.
 
The spark plugs are wet, so fuel is getting in there.

I disconnected the ECU and re-checked my Quarterhorse, just to make sure everything looks good. There's no smell of anything that's fried, and on the circuit board, nothing has blackened or bit the dust. I'm not the foremost electronics expert, but I do some electronic modifications on some of my music gear, and I know what a bad capacitor/ burnt resistor looks like, and there's nothing like that going on.

With the ECU disconnected, I tried to start the car, and there was no firm ride light on, whereas with the ECU in, the firm ride light was on (with the firm ride activated). Would this be one indication that the ECU is good? No upshift light either, and that is the sign that there is a signal at the crankshaft sensor, correct?
 
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