914-SHO Project Thread

[3d914]

Hoo-Ra! Motor is now CEL-free/No codes!

Just got in my new MAP/BP sensor (Standard Motor Products #AS13), plugged it in, fired up the motor, and no CEL lite. I did check the signal voltage which registered as 2.62v - the same as the one I borrowed from Rbruso. So I retested his, checked the voltage, got the same, but his throws a code. Weird.

 

[3d914]

Not much going on recently. Was out visiting family last weekend - had a real nice trip.
Been cold all week and working late so not planning to run the motor until this weekend. Here's the breakdown on what I need to do:

• Run engine at normal operating temp & give PCM a chance to learn
• Add some AutoRx or similar to help loosen potential stuck piston ring
• Check condition of plugs after engine run (and cool down)
• If no further codes, bring engine to normal temps & run cylinder balance test
• If valve noise continues on Cyl #3, perform tear-down and inspection of heads

 

[3d914]

Made some progress running the motor yesterday, but ran into some new issues. Posted them here for discussion (see post #13). Plan to continue running the engine to address the possible stuck piston ring before continuing with the cylinder balance test.

 

[3d914]

Well I ran it more today - but its not getting any better. In fact it sounds worse that it did before. Not valve noise - that's the same. This is more like rod noise. Decided not to run it any more and just tear it down. I've started a post about the tear down.

Guess this will give me some time to finish up some of the welding on the car too.

 

[SHOstopper1992]

Wow, I finally go caught up in this thread and I am absolutely blown away by it. Really gives me hope and motivation for my project!

Kudos.

-Stephen

 

[3d914]

Got thru the right heads today and inspected Cyls 1-3. Not looking good. Looks like I'll be removing pistons & rings shortly.

Follow along on my teardown post.

 

[3d914]

Just an update. The tear down is proving to be a slippery slope. First bad valve seals - not too bad. Pulled pistons to check them - only a couple of partially stuck rings. Checked the ring gaps - way out of spec. So that means at least a new ring set.

Now I'll have to measure the cylinders to see if they're within spec or not - and may have to go over-sized. This is just too much fun - think I need a break!

 

[3d914]

Another update. Valve assy's are back together on both heads. Cylinders appear good enough to hone and add new rings - so progress continues in the teardown post.

 

[3d914]

Still working on the motor (keeping up the teardown post) and actually did some metal work on the body.

Though cylinders are good, the pistons are out of spec so I'm hunting down some used ones that are the right size. If I can't find used pistons I'll go for another used low-miles motor before I pay $800 for new pistons. Not cheap, just on a budget & there's a lot of work to go.

 

[3d914]

Well, motor rebuilt is on the downhill side. Got the pistons back in, and the heads should follow shortly.

Keep watching.

 

[3d914]

Got the motor back on the stand and will be finishing up cooling and wiring. You can check out the rebuilt motor back on the stand here. Will try to get it set up for oil pressure buldup test by mid-week.

 

[3d914]

Good news! Its back together, full of fluids, and ready for round two of bench tests.

Just got the oil pressure test done, and the light went out in about 20 seconds.

Here's the video.

Should be ready to run this weekend.

 

[intimdatr]

Looking good! Cant wait to see this car move!

 

[Off Road SHO]

Sweet. So the starter cranked it over just fine, eh?

Tom

 

[probe_racer]

awesome Im excited that this project is finally coming together for good

I like ur engine bench test in the garage I need to build one too

 

[3d914]

awesome Im excited that this project is finally coming together for good

I like ur engine bench test in the garage I need to build one too

I've got a PDF of the plans around here somewhere if you're interested. Shoot me a PM with you're email.

 

[3d914]

Spent yesterday doing a basic breakin of the motor. Tom indicated it will be many hours before these chrome rings seat fully, so I'll just keep running it off & on while finishing the bodywork on the 914.

Here's a video of the latest run. Sound pretty good, but still getting some mild surging. Cold start seems to have more, but I'll sort that out as I go along.

 

[3d914]

OK new developments. Every time I start to get excited about this motor running, something else goes off in left field.

Started it up cold this evening to continue the breakin. TPS is set at 1800rpm, but rpms were all over the place, up & down. Now what? So I go get my timing light and put the connector on each plug wire to see if I get strobe light - indicating that at least the wire is getting voltage. A couple of the wires didn't get anything. I then noticed that the rpm gauge on the timing light was jumping also from 1200 to 3500+ rpm - but the motors set a 1800rpm.

I can't say I've seen anything like this before. Can any of the ignition components be tested (coil pack, DIS)?

 

[Off Road SHO]

Were the two cylinders that didn't get anything, happen to be paired cylinders. There are only 3 coils in the coil pack, with each coil firing two spark plugs at the same time. The cylinder on the compression stroke gets a healthy spark from its spark plug and the mated cylinders gets a weak (wasted) spark from its plug.

The paired cylinder's plug wires are across from each other on the coil pack. Cylinders 1 and 5, cylinders 2 and 6 and cylinders 3 and 4 are paired.

When the ignition is turned to "ON", I believe that all three coils are heated up with 12 volts on the red wire. The PCM then sends ground to each individual coil in sequence to charge it and when that ground is removed, the coil emits a 40,000 volt pulse, looking for a small gap to jump. At least that is how I understand it. I am not sure if the coils are grounded by the computer at all times or only when it's time to get ready to fire.

Tom

 

[3d914]

Were the two cylinders that didn't get anything, happen to be paired cylinders. There are only 3 coils in the coil pack, with each coil firing two spark plugs at the same time. The cylinder on the compression stroke gets a healthy spark from its spark plug and the mated cylinders gets a weak (wasted) spark from its plug.

The paired cylinder's plug wires are across from each other on the coil pack. Cylinders 1 and 5, cylinders 2 and 6 and cylinders 3 and 4 are paired.

When the ignition is turned to "ON", I believe that all three coils are heated up with 12 volts on the red wire. The PCM then sends ground to each individual coil in sequence to charge it and when that ground is removed, the coil emits a 40,000 volt pulse, looking for a small gap to jump. At least that is how I understand it. I am not sure if the coils are grounded by the computer at all times or only when it's time to get ready to fire.

Tom

Tom, I didn't notice the relationship to the cylinders. I'll test it again tomorrow and make better notes.

The rpm reading on the timing light really through me too. But after reading more in the engine book I have if its getting two fire signals (one compression, one wasted spark) then wouldn't a standard timing light pick up both pulses thereby doubling the rpm reading?