2nd Gen (86) - Help!!!

[Eagle7]

I'm typing this instead of rolling into Blackhawk for my driver's school. If you can help me maybe I can make it to the second day. It's been a real ordeal trying to get the car prepared.

I bought the (previously logged and raced) car with the engine out of it. I don't think this engine was ever in the car before I got it.

Symptoms: Won't start unless I hold open the door in the air flow meter. It needs starting fluid when it's cold. Once it starts it runs quite rough, and won't come close to idling, even when it's hot.

I made a two-light arrangement to adjust the TPS and to check the ECU codes. TPS adjusts OK. No ECU codes.

What's installed:
Air flow meter & funnel
Air bypass solenoid valve
Boost sensor
Intake air temp sensor
Water thermo sensor

What's not installed:
Dash pot
Bypass air control valve
EGR valve & EGR solenoid valve
Air pump & all related stuff
Pressure regulator control solenoid valve (regulator vacuum hose connected to intake manifold)

The L1 & L1 plugs fire on the leading timing mark. T1 fires on the trailing mark. T2 fires nowhere near any mark (must be about 180 degrees off the marks).

I've ohmed out:
TPS (and tried a spare)
Air flow meter (and tried a spare)
Intake air temp sensor
Variable resistor

I've run with BR9EQ14 plugs all around and BRU9EQ (trailing)/BRU7EQ(leading) with no change.

I've got fresh 87 octane pump gas with about 100:1 Redline two-stroke oil premixed. Brand new fuel cell, new fuel pump, new fuel lines all the way to the front.

Injector(s) condition is unknown (they all ohm out to ~13 ohms).

I don't have a clue what to try next.

Can you get me to the school tomorrow?

Thanks,
Marty

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Marty Doane
ITS RX7
CenDiv WMR

[BrianB]

Marty,
Remove the leading plugs, Turn the engine over with the starter, listen for even,regular compression pulses from the spark plug holes.Missed pulses would suggest a bad apex seal,lack of compression.If this is good, Check the bypass air control set up(if it hasn't been eliminated),look for an opening (vacumn leak)to the intake that's between the AFM an the intake runners.With good compression and no vacumn leaks, the engine vacumn should open the AFM door,which also turns the fuel pump on. If your plugs are wet,possibly bad injectors, try connecting a vacumn hose from the fuel pressure reg.on the fuel rail to a vacumn fitting on the engine side of the throttle plates to lower the fuel pressure at idle. There is a plastic hose connector on the intake tube for the bypass air control, if this is open (unpluged) this could be your problem.
Just a few guesses,good luck,
B

[BrianB]

One other simple thing, Try it first! Just disconnect the battery, then reconnect to reset the ECU. This worked for a friend that couldn't get a new motor to run.
B

[xr4racer]

Check your grounds for the injectors, for that matter do you have high impedance or low impedance injectors? Do they match the wiring harness you have? I would look at all grounds (one is under the aluminum upper intake tubes), I would also check for a big vacuum leak ( around injectors, in the intake tube as described above and between the sections of the manifold.) What year was the engine and what year is the wiring harness?

[Eagle7]

We found that the intake manifold was not seated properly, and think that we've solved that, but it was too late (neighbors) to be running the engine for testing. A quick test showed improvement but not solved. Back to it now.


<font face=\"Verdana, Arial\" size=\"2\">Check your grounds for the injectors, </font>
I don't understand. Looks to me like the injector doesn't use a ground, just the two dedicated wires in the harness.


<font face=\"Verdana, Arial\" size=\"2\">for that matter do you have high impedance or low impedance injectors? </font>
I'm running 13 ohm injectors, which have a key on the connector that's offset from the center. I assume they're high impedence, since I've also got a couple 2 ohm injectors with the key centered in the connector. The '88 doner car I've got has the 13 ohm injectors, as does a spare engine I've got.


<font face=\"Verdana, Arial\" size=\"2\">Do they match the wiring harness you have? </font>
The injector wiring on the harness was already cobbled up when I got the car.


<font face=\"Verdana, Arial\" size=\"2\">I would look at all grounds (one is under the aluminum upper intake tubes), </font>
That looks good.


<font face=\"Verdana, Arial\" size=\"2\">I would also check for a big vacuum leak ( around injectors, in the intake tube as described above and between the sections of the manifold.) </font>
Bingo.


<font face=\"Verdana, Arial\" size=\"2\">What year was the engine </font>
How can I tell?


<font face=\"Verdana, Arial\" size=\"2\">and what year is the wiring harness?</font>
'86

You guys are great. Back at it.
Marty

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Marty Doane
ITS RX7
CenDiv WMR

[This message has been edited by Eagle7 (edited April 25, 2003).]

[Eagle7]

Crisis has now passed. We missed the second school too. Bummer, because now I'm afraid I can't get two schools in before late fall.

We fixed a large intake leak - interference prevented it from seating correctly. However, although it now runs much better, it's still not right.

The #2 header pipe turns cherry red (got to be lean), so I think I'm either looking for poor fuel injection on the #2 primary or a leak in a #2 runner. We checked the vacuum of each runner using the small ports on the front of the intake. The front three go up to 20 PSI on the decel after a rev, but the rear-most one only hits 11 PSI (my gauge might be out of calibration). We've torn it apart looking for a leak in that last runner, and ran out of time to make the school.

Once we had it apart, I questioned whether that was a valid measurement, because those outer ports connect into the injector assembly through a very small pinhole that may prevent getting a good reading.

We also inspected the primary injectors and decided to swap them with injectors from the spare engine, because one had a bulge in it and the other was cracked.

Now that this school is passed, the next hard deadline is probably the June school at Gingerman, so the pressure is off. Anyone know of any other SCCA-approved schools within a reasonable distance of Michigan before the end of the summer, so I can get school #2 in and actually get racing this year?

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Marty Doane
ITS RX7
CenDiv WMR

[xr4racer]

There is a school at Nelson Ledges in July, the weekend after the national. You do not have the silver resistor box for the injectors hooked up do you? It is located up by the boost sensor and is held on with a couple of bolts. If your car is an 86, it would have originally had this box wired in (basically resistors for the injectors that were low impedance). If you have the later 13 ohm injectors and the resistor box wired in you are running 23 ohms.

[Eagle7]

Originally posted by xr4racer:
There is a school at Nelson Ledges in July, the weekend after the national.
Thanks for that info. I thought NL had cancelled all the schools until Oct. An email confirmed they're planning a school July 19-20, but they say it is not yet firm.


<font face=\"Verdana, Arial\" size=\"2\">You do not have the silver resistor box for the injectors hooked up do you? It is located up by the boost sensor and is held on with a couple of bolts. If your car is an 86, it would have originally had this box wired in (basically resistors for the injectors that were low impedance). If you have the later 13 ohm injectors and the resistor box wired in you are running 23 ohms.</font>[/b]
Thanks for the education. I was really wondering about the difference in impedence. Yes, the resistor box was still in place (since been removed, and the 5 wires in that connector all jumpered together).

I've searched and searched for a leak in the #4 runner and have replaced the primary injectors and seals (along with the aforementioned wiring change). The rear header pipe still turns red, even running at about 1000 RPM. I don't yet have updated vacuum measurements. I'm assuming the glowing header is not normal. Can someone confirm?

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Marty Doane
ITS RX7
CenDiv WMR

[xr4racer]

Did you replace the seal that the injector sits down on? The only other thing I can think of would be the oil injector or an open port on the manifold assembly ( there are several that need plugged when things are not used). I would check by spraying carb cleaner or something around the manifold and looking for a change in rpm. Also check around the shafts on the throttle body for leaks.

[eprodrx7]

Marty,
Look under the primary injectors. There is a small brown atomizer and port seal (two pieces). The seal has two orings on it and the atomizer sits under it. Then the injector with seal (black about 3/16" thick hard rubber). Also do not forget the spacer that goes between the center motor housing and the fuel rail mount. It's black plastic about 1.5"x5/8" two holes and about 1/8 thick. The injectors shoud turn easly after assembly and NOT be clamped in place.
Good luck
John

[jrx13]

Are you still running an Air Control Valve or did you remove it and block it off? Just wondering. Have you got the car to idle yet? My thoughts with a glowing header on only one side usually means a compression problem. If it is hard to idle, I would suspect a problem with #2 chamber.

[BrianB]

Marty,
You might check the brake booster vacumn line for a leak. It connects to the lower manifold near the back runner.
B

[Eagle7]

OK, the good news is that it idles pretty well now. Fixed the intake leak, adjusted the timing and the idle/mixture. Can't get down to 750 RPM, but it's pretty decent at 850.

The bad news is the compression test. 90 PSI peak and regular on #2, but irregular and 60 PSI peak on #1. How much trouble is that? Do I fix it now or run it awhile? I'm guessing there's a likelihood of creating more damage if I run it, turning a minor rebuild into a major one?

If I need to deal with it now, can I do a compression test on the spare engine before I install it? Seems like I could mate a tranny to it, stick on a starter motor and test, although I can't get it warm first.

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Marty Doane
ITS RX7
CenDiv WMR

[Eagle7]

I got it out of the garage today. Junk. I've got a stock RX-7 that's got at least twice the power. I also got my exhaust gas temp gauge working today. #1 has no heat in it. I definitely have to go to another engine.

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Marty Doane
ITS RX7
CenDiv WMR