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View Full Version : KA24DET build cranks but wont run


SpaceKADET
10-18-2020, 06:27 PM
Alright, so I've been working on my pet project for quite some time now. This is a 2004 Frontier with the truck version of the KA24DE. I inherited the build that had some underlying issues and now I'm at the point where its all back together. I'm right on the edge of getting it running but I keep on running into road blocks. I have the engine turning over, but it doesn't seem to want to run at all despite there being fuel and spark. Here's a bit of a breakdown:

- Truck has strong spark, plugs are brand new BKR7E's.
- Double checked the distributor timing, it was off originally, set engine to TDC on compression stroke and re-timed driveshaft for oil pump and distributor as necessary.
- Truck has fuel, but I did find that the diaphragm for the fuel pressure regulator was beginning to leak fuel info the vacuum side, but theoretically shouldn't keep truck from running? (rebuild kit is already on it's way)
- I am running Injector Dynamics 850cc top feed injectors in an Xcessive intake manifold with an S14 throttle body. I double checked that the injectors are wired correctly and going to the correct cylinders.
- Truck has an S13 ECM with an adapter harness to run through the stock engine harness and personally double checked every single wire utilizing FSM's for both vehicles.
- The only code registering in the ECM is for the knock sensor which is not plugged in.
- Truck has 300zx mass air flow sensor. Checked both ground wires and they are good.
- New battery.
- New BC stage 2 turbo cams (240SX spec) and brand new timing chain kit.
- I do not have one or two sensors plugged in on the back of the transmission (5MT), I believe they are inconsequential.
- I don't have the O2 sensor installed or plugged in currently (should only be an issue during open loop?)
- ECM is a unit from RS Enthalpy that looks like it has had one of the power traces repaired in the past. ECM has a base-map on it for my injector size and Z32 MAF.

I was thinking of checking the mass air flow sensor for input/output voltage? The exhaust cam looks to be in the correct position when viewing it through the oil cap with the engine at TDC on 1. Short of pulling the timing and valve covers to double check the timing there, I'm at a loss. I feel like there's some obscure bit of info that I'm not privy to that is the key to getting this thing cooking.

OnTheChip
10-19-2020, 12:50 PM
The FPR diaphragm leak will flood the engine quickly. Can you check the plugs to see if they are wet with fuel?

PoorMans180SX
10-19-2020, 01:52 PM
The FPR diaphragm leak will flood the engine quickly. Can you check the plugs to see if they are wet with fuel?

Yup, do that.

Also try starting it with ether, in case it's not getting enough fuel.

Give us some more information, does it pop when you crank it? Nothing? Is the fuel pump working?

SpaceKADET
10-20-2020, 04:08 PM
The plugs weren't soaked but they were misted with fuel. I get no sort of pops or backfires which is kind of throwing me off. The new diaphragm is on order so that'll be fixed shortly but I figured I would still get some kind of backfire or something. The fuel pump is running and I am getting over 40psi of fuel pressure but it falls off very fast, due to the leaky diaphragm I assume.

S14rebuild
10-20-2020, 05:24 PM
100% sure mechanical and ignition timing is correct?

Have u tried disabling fuel system qnd running it on starting fluid?

SpaceKADET
10-20-2020, 05:46 PM
The drive for the distributor off of the crank is exactly where it should be. I'm guesstimating where the distributor should be clocked as it's difficult to use a timing light with the engine not running. I need to lift the valve cover to double check the cam timing relative to tdc on the crank pulley. I haven't tried starting fluid or ether yet. I'll give a few of these things a go this weekend and run from there.

SpaceKADET
10-24-2020, 03:31 PM
So today I worked on the truck some more. Replaced the diaphragm for the fuel pressure regulator and performed a compression check. I had no compression on any cylinder, leading me to believe I have an issue with timing. Pulled the valve cover off and checked the positioning of the cams at TDC. The positions look nothing like what I expected to see, though everything I've seen so far has been trucks with stock cams. How much different would it really be even if it was an aggressive cam? The cams are BC0211 "stage 2" cams. I looked up timing diagrams, but if I set it to fsm specs, it still looks off by a large margin and appears to have valve interference with the crank. If i set the timing using the other timing mark on the intake cam, it's still off but rotates without interference (this is the way it was before i touched the timing). I don't particularly want to break down the front timing cover and start from scratch with the timing because I really don't think it will even solve my issue at this point. I'll try and add photos as soon as I can.

S14rebuild
10-24-2020, 04:54 PM
The timing all ka24de are all the same.

On tdc compression..cyl 1 should be completely up. And both intake and exhaust lobes should be pointing 180 opposite of one another pointing out.

Thats close. Then all timing marks should be lined up properly

I think your best bet is to pull the front covers, reset timing bybfsm and post pictures up so we can see whats going on aswell

SpaceKADET
10-24-2020, 06:20 PM
Worked a little more on it. I feel I should clarify on a few things. The exhaust cam has been timed properly from the beginning, the issue only seems to be with the intake cam and I have a theory as to why that is. I have already removed the valve cover and the upper portion of the front timing cover to confirm my findings.

Here's the timing I started with before touching anything. 0 Compression for obvious reasons:
https://live.staticflickr.com/65535/50524688733_afe1a623bb_c.jpg

Here's what happened when I followed the FSM to the letter. This caused valve interference with the piston:
https://live.staticflickr.com/65535/50524689793_d19af95370_c.jpg

After trying to set the timing like a sane person, I went ahead and set the intake cam to the position where the cam lobes were lined up the way they are supposed to be. This threw out the window the idea of using any kind of timing mark on the intake cam sprocket. I turned the engine over by hand and there was no interference. I hooked up the battery and the compression gauge. Surprise surprise, I now have compression on all cylinders.

Here's my theory as to why this is. According to one post on Nico Club (LINK HERE) (https://forums.nicoclub.com/ka24de-cams-specifications-t169323.html) regarding cams, apparently "the ?98 up intake cams had the dowel pin relocated to match the same 12 o?clock position as the exhaust cam has" so if the cams that I got were specifically designed for a 91-97 engine, then only the intake cam timing would be affected. Since this is a 2004 production engine, this kind of makes sense. Unfortunately I can't find anything on the Brian Crower website that would corroborate this so I may call them on Monday.

Has anyone else encountered anything like this? My plan is to just leave the cam where it is now and see what happens. Either way, I've spent the last 6 weeks trying to get this thing running and this is the only thing that seems logical.

SpaceKADET
11-02-2020, 04:56 PM
Well I had written out a pretty decent reply with pictures and everything over a week ago, but I guess it still needs to be approved by a moderator. There is a difference in the locating dowel for the intake cam depending on what year car the cams are meant for. After taking that into account, I was able to get it timed right. The distributor also failed somehow after sitting for so long and was causing the injectors to dump fuel. After getting another dizzy from the junkyard, I was able to get it running, though it doesn't idle on it's own, maybe due to not having an IACV or one of the various sensors not being plugged in.

S14rebuild
11-05-2020, 02:46 PM
Needs the IACV to idle, or crack open the throttle plate some

SpaceKADET
11-05-2020, 03:15 PM
I guess I need to figure out how to run an IACV with an Xcessive intake manifold then.