The saga continues.

[nmhenry]

Finally got the daughter's 88 running. New timing chain, magnet, MAF, CTS, EGR valve, eliminated cat, new O2 sensor, ICM, coil, plugs, wires, Cam position sensor, crank sensor, PCV valve and grommets, and fuel filter, replaced every rubber vacuum line.
 No codes but it has low vacuum at idle. about 20 when I increase the throttle.
ED01 = 0.40
ED099= 2544  Prom ID
ED098= 14
ED023= 20 degrees
ED022= 24
ED021= 4.3
ED020=155
ED019= 142
ED18= 1-8
ED17= 281
ED16= 0
ED11= 748
ED10= 13.9
ED08 = 20 degrees
ED07 = .05-086
ED04 = 93
ED06= 4.5-4.9
Accelerates good, no misfire at RPM, good throttle response, runs excellent until you get to closed loop and then idle. Idle does fluctuate from about 625 to 725.
 Is it possible that I have an intake leak even though I have no coolant in the exhaust or in the oil? There are no external leaks from the intake either.
 I get that it thinks it is running lean and is trying to compensate.
 


 

[rogold99]

Have you checked the vacuum to the HVAC Control Module, behind the glove box? Maybe the module is leaking vacuum internally. Or maybe the Vacuum reservoir tank is leaking. Or maybe the black vacuum manifold on top of the engine is cracked or the gasket under it is bad. Reatta Owners Journal . 

[2seater]

ED 19 & 20 are both adding more fuel, but it is difficult to judge at idle speed. It is not unusual for that to happen, especially an extended idle. Throttle up a bit, say 1500 rpm for a bit and see what those two readings do. The rest of the readings look pretty normal. What do you consider low vacuum at idle? Mine is about 18" at 800ft above sea level for idle in park but this engine seems to be slightly lower at 16-17". Increased altitude will probably reduce indicated vacuum, but I cannot verify that. Idle air control needs cleaning perhaps if the idle is unstable. You can watch the ED22 idle control to see what is doing.

[nmhenry]

8 hours ago, 2seater said:

ED 19 & 20 are both adding more fuel, but it is difficult to judge at idle speed. It is not unusual for that to happen, especially an extended idle. Throttle up a bit, say 1500 rpm for a bit and see what those two readings do. The rest of the readings look pretty normal. What do you consider low vacuum at idle? Mine is about 18" at 800ft above sea level for idle in park but this engine seems to be slightly lower at 16-17". Increased altitude will probably reduce indicated vacuum, but I cannot verify that. Idle air control needs cleaning perhaps if the idle is unstable. You can watch the ED22 idle control to see what is doing.

I had replaced the IAC a couple of months ago. and cleaned the port for the IAC. May pull the throttle body and clean it.

 

[Ronnie]

11 hours ago, nmhenry said:

Accelerates good, no misfire at RPM, good throttle response, runs excellent until you get to closed loop and then idle. ...

Are you saying that it runs as it should until it goes into closed loop and then it starts running poorly or is the idle the only problem in closed loop? Please clarify.

[nmhenry]

19 minutes ago, Ronnie said:

Are you saying that it runs as it should until it goes into closed loop and then it starts running poorly or is the idle the only problem in closed loop? Please clarify.

 That's pretty much the gist of it. It is running rich at idle. You can smell the gas at the exhaust and it has very poor idle. When started warm after sitting for a while it misfires like an older engine with the choke stuck closed and will do so until I get on it and cleat its throat.
 I noticed a fuel smell in the intake when I was changing the MAF. Possible leaking injectors? Fuel pressure will drop to zero after sitting for about an hour but that may be normal?

 

[2seater]

Maybe I have forgotten but did you check for fuel in the vacuum line to the fuel pressure regulator?

[2seater]

The fuel pressure will usually have some residual pressure for longer than an hour, but there is no set value as long as it doesn't drop to zero immediately. There are three ways for it to bleed off, other than an external leak, leaky injector as stated, through the pressure regulator and back through the pump in the tank. 

[Ronnie]

Just a shot in the dark... I would disconnect the O2 sensor, which will prevent it from going into closed loop, and drive it until fully warmed up and see if the problem persists. That might tell you if the problem is with the fuel injection system injecting too much fuel in closed loop because of a bad sensor or ECM, OR there is something else going on.

[nmhenry]

20 minutes ago, Ronnie said:

Just a shot in the dark... I would disconnect the O2 sensor, which will prevent it from going into closed loop, and drive it until fully warmed up and see if the problem persists. That might tell you if the problem is with the fuel injection system injecting too much fuel in closed loop because of a bad sensor or ECM, OR there is something else going on.

Already tried that. No difference.

Going to convert to Delco ignition tomorrow night or this weekend to see if that helps.
 I vacuum tested the fuel pressure regulator and it held vacuum though that doesn't mean that the regulator is good.

 Wish there was an easy way to test for a leaky injector.

 

[rogold99]

I think I did this test before; I pulled the fuel rail loose from the manifold with the injectors still attached, bagged the injectors with ziplock bags, then turn the key to on to build pressure in the line. A leaky injector should start filling the bag. You would have to change the O-rings on the injectors before reinstalling, but they are cheap.

[Ronnie]

1 hour ago, nmhenry said:

Wish there was an easy way to test for a leaky injector.

If you think when the engine is shut off that pressure in the system is pushing fuel through a leaking injector and flooding the engine you could try relieving the pressure in the system with the schrader valve as soon as you shut the engine off. Then see if you have the same issues on startup as you described earlier.

[rogold99]

    I have also done this; I plugged off the output of the fuel pressure regulator with an oil pan bolt that I found at the auto parts store that had the same threads. then connected the fuel pressure gauge to the fuel rail, then turn on the key for a few seconds. If it holds pressure, then the fuel pump and fuel injectors are good.

    This may not be a good test of the fuel pressure regulator though, because you may be blocking off the port it is leaking out of with the bolt.

[2seater]

24 minutes ago, rogold99 said:

    I have also done this; I plugged off the output of the fuel pressure regulator with an oil pan bolt that I found at the auto parts store that had the same threads. then connected the fuel pressure gauge to the fuel rail, then turn on the key for a few seconds. If it holds pressure, then the fuel pump and fuel injectors are good.

    This may not be a good test of the fuel pressure regulator though, because you may be blocking off the port it is leaking out of with the bolt.

Similar to the fuel injector test above, the return line can be left open with a catch can or bag. Might be easier with 12v to the green prime connector for finer control, but the regulator should not return any fuel at a pressure lower than the base pressure of ~3bar or 43.5psi. If it leaks through it wouldn't flood the engine but it would bleed pressure when off. Just bring it up to 35-40psi and no fuel should pass the regulator to return.

[nmhenry]

10 hours ago, Ronnie said:

If you think when the engine is shut off that pressure in the system is pushing fuel through a leaking injector and flooding the engine you could try relieving the pressure in the system with the schrader valve as soon as you shut the engine off. Then see if you have the same issues on startup as you described earlier.

Thanks. I will try that. I don't know why I didn't think of it.

 

[padgett]

For me I just check for gasoline in the fuel regulator vacuum line.

[nmhenry]

5 hours ago, padgett said:

For me I just check for gasoline in the fuel regulator vacuum line.

Did that. No gas in the line and the regulator holds vacuum

[nmhenry]

Update:
 Ugraded to Delco ignition and coils. Runs much better. I will see in a little while how it starts warm but so far so good.
 Idle still feels a little rough but that may be due to old motor mounts. They need replaced.
 

[nmhenry]

 I now have the intake off of it. The vacuum manifold on top was loose. EGR gasket was burnt between two ports and the center and two intake ports on the heads look like they have been sucking oil past the intake gasket. I am changing every gasket and O-ring on top of the engine now.
 Has anyone ever threaded the heater pipe port to pipe thread, put a hose nipple in there and done away with the pipe?

 

[2seater]

1 hour ago, nmhenry said:

 Has anyone ever threaded the heater pipe port to pipe thread, put a hose nipple in there and done away with the pipe?

 

I do that to every one I take apart. From memory, the small one for the upper pipe is 1/4" npt and the large one that bolts to the vertical face as a flange is a loose 3/8" npt. I coat with JB weld when I install the plug. Alternately, if the studs are good, just make a blank plate and block it off. My car is summer only but I do drive it in below freezing weather if the roads are dry before putting it away and it has never caused a problem. One small item is I use socket head brass plugs because they look neater IMHO

[nmhenry]

3 hours ago, 2seater said:

I do that to every one I take apart. From memory, the small one for the upper pipe is 1/4" npt and the large one that bolts to the vertical face as a flange is a loose 3/8" npt. I coat with JB weld when I install the plug. Alternately, if the studs are good, just make a blank plate and block it off. My car is summer only but I do drive it in below freezing weather if the roads are dry before putting it away and it has never caused a problem. One small item is I use socket head brass plugs because they look neater IMHO

The hole in the end of the intake looks like it would have to be threaded at least 1/2" NPT. Looks to be enough material to thread deeply enough. I'll probably take to a local machine shop that I have a good working relationship with and get them to do it.

 

[Larry Schramm]

If you want to check the ignition system, here is how it is done.  It is actually in a service procedure of the day.

 

Vehicles of that era had issues with the coil packs going bad. 

 

Easy way to check the integrity of the coils is to purchase 3 of these spark testers.  

 

 

Remove one of the spark plug wires for each of the coils, put the spark plug wire on the tester top, clip the tester onto the coil tower and then start the car.

 

If the car will idle for about 10 minutes without starting to miss or stumble, the coils and ignition system is fine.  If it starts to miss/stumble, look at which tester is not sparking.  That is the bad coil. 

 

There were two types of coils used in that era.  The single coil pack made by Magnavox will require the complete coil pack to be replaced.  The other style is three individual coils made by Delco are replaceable individually. You only need to replace the bad coil. 

 

Also when looking at the coil area, be sure to check the ground that is under the coil pack.  Make sure you remove, clean, and retighten the surfaces on both ends of the wire.  It will save you other issues.

[padgett]

The later Delco is also more powerful & is plug and play.. See here.

 

ps I have several of these. Are easier to see and less expensive.

Edited November 9, 2022 by padgett (see edit history)

[nmhenry]

On 11/9/2022 at 10:50 AM, padgett said:

The later Delco is also more powerful & is plug and play.. See here.

 

ps I have several of these. Are easier to see and less expensive.

 I have installed the Delco system on this car.

 

[nmhenry]

On 11/9/2022 at 7:36 AM, Larry Schramm said:

If you want to check the ignition system, here is how it is done.  It is actually in a service procedure of the day.

 

Vehicles of that era had issues with the coil packs going bad. 

 

Easy way to check the integrity of the coils is to purchase 3 of these spark testers.  

 

 

Remove one of the spark plug wires for each of the coils, put the spark plug wire on the tester top, clip the tester onto the coil tower and then start the car.

 

If the car will idle for about 10 minutes without starting to miss or stumble, the coils and ignition system is fine.  If it starts to miss/stumble, look at which tester is not sparking.  That is the bad coil. 

 

There were two types of coils used in that era.  The single coil pack made by Magnavox will require the complete coil pack to be replaced.  The other style is three individual coils made by Delco are replaceable individually. You only need to replace the bad coil. 

 

Also when looking at the coil area, be sure to check the ground that is under the coil pack.  Make sure you remove, clean, and retighten the surfaces on both ends of the wire.  It will save you other issues.

 I know it is not ignition issue.  I have already tested that and even installed a Delco unit.
 I am leaning towards fuel now. I have changed fuel pump and filter and now I have a set of injectors ordered and a new regulator.

 

[nmhenry]

Well, Through the process of elimination I have eliminated the ignition, engine management, and exhaust systems as the cause of my issue. I have also eliminated vacuum leaks as my issue. The car now holds 17-18 inches of vacuum.
 I am now concentrating on fuel system. I had previously replaced fuel filter and have replaced the pump and sock. I now have a set of injectors and fuel pressure regulator ordered.
 Wish me luck.

 

[2seater]

OE style injector or something else?

[padgett]

Bad fuel pressure regulator often has gas in the vacuum line.

I have a fuel pressure gauge on a long hose that can make visible from the driver's seat with the hood down. 38-40 psi at idle. Today would probably build something with an oil pressure gauge sensor hooked to a Bluetooth transmitter so I could log. Only problem is my CTS is DI.

ps IR gun on each manifold can tell if one cyl is missing or random. Modern toys are great.

[nmhenry]

3 hours ago, 2seater said:

OE style injector or something else?

 I'm going with CS performance upgrade injectors.
https://www.cspinjectors.com/shop-all/upgrade-fuel-injectors/upgrade-fuel-injector-for-280150901/

 

[nmhenry]

2 hours ago, padgett said:

Bad fuel pressure regulator often has gas in the vacuum line.

I have a fuel pressure gauge on a long hose that can make visible from the driver's seat with the hood down. 38-40 psi at idle. Today would probably build something with an oil pressure gauge sensor hooked to a Bluetooth transmitter so I could log. Only problem is my CTS is DI.

ps IR gun on each manifold can tell if one cyl is missing or random. Modern toys are great.

No fuel in vacuum line.

[2seater]

20 minutes ago, nmhenry said:

 I'm going with CS performance upgrade injectors.
https://www.cspinjectors.com/shop-all/upgrade-fuel-injectors/upgrade-fuel-injector-for-280150901/

 

Good choice. My limited experience with the Type 3 is a slightly better idle. The original 901's are a good injector with the multi directional spray pattern but the lighter internal construction of the Type3 snaps open and closed more quickly.

[nmhenry]

4 hours ago, 2seater said:

Good choice. My limited experience with the Type 3 is a slightly better idle. The original 901's are a good injector with the multi directional spray pattern but the lighter internal construction of the Type3 snaps open and closed more quickly.

 That is what the site said. I figured for $10 more per set I couldn't go wrong.
 Hopefully this fixes the problem. I have literally changed everything else.

 

[handmedownreatta]

have you thought of just taking it to the buick dealer and say fix it?might be expensive.

 

[nmhenry]

On 12/4/2022 at 9:08 AM, handmedownreatta said:

have you thought of just taking it to the buick dealer and say fix it?might be expensive.

 

 Our Buick dealer won't touch anything over ten years old.

[nmhenry]

On 12/1/2022 at 5:48 PM, nmhenry said:

 That is what the site said. I figured for $10 more per set I couldn't go wrong.
 Hopefully this fixes the problem. I have literally changed everything else.

 

 New injectors seemed to have helped some but the problem persists.
 I have unplugged the fuel pressure regulator and plugged the vacuum port and it seems to idle better hot.
 I tapped on it after I shut the engine down and the pressure actually increased according to my gauge. It did drop tp 20 psi in about 30 minutes but it did prime and start right up.
 I am wondering if the decrease in pressure is allowing the fuel to boil in the line or in the rail and is basically vapor locking the system until enough cool fuel flows to cool everything down? Seems unlikely though.

 

[2seater]

Not unusual for the fuel pressure to increase after shutdown of a warm engine. If everything seals up well, the injectors, fuel pump and the regulator, the trapped fuel in the rail will naturally expand from the heat. The running fuel pressure is less than the mechanical spring relief of ~43.5psi. The manifold vacuum reduction in fuel pressure stops at shutdown but the mechanical limit remains. I have never seen one increase to the point of the relief pressure but a rise of several psi is pretty common. I doubt there is a vapor lock situation since the fuel remains under considerable pressure until it cools, although I have no proof that it can't happen. The circulating nature of the system would tend to eliminate any vapor if present almost immediately. A deadheaded fuel pump is capable of ~100psi.

[nmhenry]

21 hours ago, 2seater said:

Not unusual for the fuel pressure to increase after shutdown of a warm engine. If everything seals up well, the injectors, fuel pump and the regulator, the trapped fuel in the rail will naturally expand from the heat. The running fuel pressure is less than the mechanical spring relief of ~43.5psi. The manifold vacuum reduction in fuel pressure stops at shutdown but the mechanical limit remains. I have never seen one increase to the point of the relief pressure but a rise of several psi is pretty common. I doubt there is a vapor lock situation since the fuel remains under considerable pressure until it cools, although I have no proof that it can't happen. The circulating nature of the system would tend to eliminate any vapor if present almost immediately. A deadheaded fuel pump is capable of ~100psi.

 Would there be any negative effects of running with the regulator disconnected?

[2seater]

2 hours ago, nmhenry said:

 Would there be any negative effects of running with the regulator disconnected?

If by disconnected, you mean with the vacuum removed, there will be no harm done. It may run slightly rich for a bit, especially open loop, but eventually the O2 sensor will adjust the injector pulse width to compensate. It has the effect of making the injector slightly larger when running with vacuum in the intake manifold, which is all the time except at wide open throttle. The purpose of the vacuum caused fuel pressure reduction is to keep the pressure differential at the injector tip relatively constant. Two inches Hg of manifold vacuum is roughly equivalent to one psi fuel pressure reduction. Within limits, the higher pressure differential atomizes the fuel better.

[EmTee]

On 12/6/2022 at 9:26 PM, nmhenry said:

I have unplugged the fuel pressure regulator and plugged the vacuum port and it seems to idle better hot.

 

9 hours ago, 2seater said:

It has the effect of making the injector slightly larger when running with vacuum in the intake manifold, which is all the time except at wide open throttle.

These two comments make me suspect a vacuum leak.  Has the intake manifold ever been removed?  Disconnect and plug vacuum lines one at a time to note any change in idle quality.  Check the vacuum accessories with a hand vacuum pump to test for leaks.

 

On 12/1/2022 at 8:37 AM, nmhenry said:

I have also eliminated vacuum leaks as my issue. The car now holds 17-18 inches of vacuum.

The idle vacuum reading above does not rule-out a vacuum leak sufficient to affect idle quality.

[nmhenry]

59 minutes ago, EmTee said:

 

These two comments make me suspect a vacuum leak.  Has the intake manifold ever been removed?  Disconnect and plug vacuum lines one at a time to note any change in idle quality.  Check the vacuum accessories with a hand vacuum pump to test for leaks.

 

The idle vacuum reading above does not rule-out a vacuum leak sufficient to affect idle quality.

 I have changed the intake gasket, throttle body mounting gaskets, EGR gaskets and valve, IAC and o-ring, built a new vacuum tree and made a gasket for it, changed every rubber vacuum line I could find, tested all the vacuum circuits with a hand held vacuum pump and they hold vacuum, changed the PCV grommets and valve, and sprayed more cans of carb cleaner around everywhere to attempt to find vacuum leaks. Maybe there is something I missed but I don't think so.