Christian's build in MA; US Exocet #148

[buildercg]

Blew out the fuel lines, added new gas, and turned the key. It started on the second crank and runs!

It's a bit rough so now I get to learn how to use a timing light.

[buildercg]

I worked on the idle issue and timing. I spent about 20 minutes trying to find the timing marks on the pulley. I could only find one (the engine is a '91). I marked it with whiteout and started the car. Idle was up around 1200-1400, with some roughness. It will drop and see-saw after running steady for a minute or two.

I used the set screw to bring it down to around 800-850 and let the car warm up. I then set the computer in diagnostic mode and hooked up the timing gun. Timing was at about 16, so I adjusted to 10 and made a small adjustment to idle as it was low. Locked down the CAS and double checked timing was still at 10. 

After setting the timing, the engine is still see-sawing at idle off and on. It will be steady for a minute or two, then see-saw (unsteady idle between 500 and 1000 rpm) and then recover and then repeat the cycle. I found that by giving it a little gas I can make this stop for a while but if I let it idle for a couple of minutes it will start to do this again. 

So I put the idle concern aside, put the bodywork back on the car, hooked up lights and went for a very short (<1 mile) test drive. The car drove great except when I was coasting up to stop sign and the idle issue occurred. Otherwise, it pulled nicely (didn't go fast or loud; it's my neighborhood and it's after 11pm; don't want angry neighbors) and I didn't otherwise notice anything unusual.

The gas tank is about 50% full and the idle issue was happening when the car wasn't moving. Doesn't seem like a fuel supply and I've previously checked spark. Any idea why the see-saw in the idle is occurring? Could I have a cylinder only firing some of the time?
I'm going to pull the plugs tomorrow to check them. 


New pump is great btw, I can hear the gas flowing when I have my pump switch on before starting the car.

[gwnwar]

Great to hear it is running.. I would set timing to 14deg it will give you a little more low end pull power..
When you set the timing and idle speed after warm up did you have the Ten and Grd in Dia box jumped.
Should be jumped..
Go for an idle speed when warm 800 +/-50 rpms..
Idle speed control valve on bottom of throttle body might be bad.. Do to have the hoses to it install on all the way..
Any small vac leaks..

[buildercg]

Jul 21, 2017 6:31:38 GMT gwnwar said:

Great to hear it is running.. I would set timing to 14deg it will give you a little more low end pull power..
When you set the timing and idle speed after warm up did you have the Ten and Grd in Dia box jumped.
Should be jumped..
Go for an idle speed when warm 800 +/-50 rpms..
Idle speed control valve on bottom of throttle body might be bad.. Do to have the hoses to it install on all the way..
Any small vac leaks..

Yes, i had ten and ground jumped. Will adjust timing to 14 next time I have the nose off. I will check for vac leaks this weekend.

[einy]

Use premium fuel if you go to 14 !!!

[buildercg]

Thanks einy.

I wasn't able to find any vac leaks last night. I drove it a few miles and everything was good, except the idle issue at traffic lights. No codes on the computer.

I'm taking the car for state inspection today. I already know I'll fail emissions because of how the car is registered but if I pass on safety then I know I'm in good shape overall.

[buildercg]

I spent a few more hours trying to find a leak. With the engine running I can hear something hissing but cannot find any leak. I might be hearing the fuel through the rail, as the new pump really moves the fuel and using my fuel pump switch with the engine off I can hear fuel moving through the rail from the driver seat and the sound is very similar to what I hear when the engine is running.

I double checked the computer for codes and nothing is coming up, I think. With the engine off, I jump the TEN and ground on the diagnostic port, and turn key to ON without starting the engine. The engine light stays on for about 3 seconds then goes off and stays off. I assume this means no codes.

[gwnwar]

Right no codes.. When are you going to get the alignment done.. It should make it drive different.. Make sure all vac ports on throttle body and manifold are used or capped check the bottom too. There is a rubber cap on the rear of the intake manifold,
down real low pointing toward the fire wall..Port was for auto trans cars.. If you have a cone filter it could be that.. What are you using for an intake tube from AFM to TB. OEM ones after awhile tend to crack if handles to much..

[buildercg]

alignment probably not going to get done for a few weeks...place I use requires appointments and I won't be able to do it next week; gonna be travelling the week after. I'll check for the lower cap; didn't know there was one down there.

The intake tube is an inexpensive aftermarket flex pipe as my donor had a Jackson Racing airbox which doesn't fit the Exocet. I have a K&N high-flow filter now. I'll eventually upgrade to silicon tube. I've checked the flex pipe extensively for leaks figuring that was the problem but haven't found any. I was running with it on the original engine without having this issue.

[buildercg]

Cannot get inspection today. Didn't make it out this morning and the place I go is closed for the weekend. Gotta take it early on Monday.

[buildercg]

Rubber cap on back of intake manifold is present and in good shape.

[gwnwar]

You could try spraying some starter fluid on hoses and around the intake system and manifold to head and ISC valve and its air hoses.
The big one like 1" and small to Air Valve on top of intake manifold..
Are you still having problems with the idle speed??

[buildercg]

Jul 23, 2017 0:08:23 GMT gwnwar said:

You could try spraying some starter fluid on hoses and around the intake system and manifold to head and ISC valve and its air hoses.
The big one like 1" and small to Air Valve on top of intake manifold..
Are you still having problems with the idle speed??

Yes, idle speed is still an issue.

I've done the starter fluid trick repeatedly with no success in terms of finding a leak.

Didn't get much time in the car yesterday but I did swap my plugs. The original plugs came out looking a little sooty. Did not smell of gas and no oil in them. I put the iridium plugs I had in my old engine in (they only had a few thousand miles on them) and the car started right up, though the idle issue is still present.

An uncle recommended filling the brake vacuum line with Seafoam and then starting the car, as any vac leaks would smoke. I did this and could not find any smoke, except out of the tail pipe.

[gwnwar]

Putting Seafoam in vac brake hose will not find leak as it is already in the manifold and won't come out, air being sucked in at a leak.. It will find leaks in exhaust system..
Have you checked the ISC on throttle body. with engine idling pull the elec plug off the unit.. Idle should go up. If you put connector on/off a couple of times you should hear a click (normal)..
Have good 1" hose to the ISC on unit to crossover tube
and no cracks..
Say again, does the idle raise by its self or not drop to the 800rpm you set when coming off throttle.. My mind not working this AM..

[buildercg]

Thanks for "how to check" ICS. I did not know those steps. Will try tonight.

I have looked hard at all hoses and haven't found any, though most I have not pulled off.

The idle raises and lowers itself within a range of about +/- 500 over/under "normal" idle, which I currently have at around 1000 because otherwise the engine stalls when it hits the "lower". The change in idle RPM seems random and will see-saw for 10-20 seconds unless I give the car gas, then everything is normal for a while until it happens again.