home register FAQ memberlist calendar

Go Back   Turbobricks Forums > Mechanical > maintenance & nonperformance

Reply
 
Thread Tools Display Modes
Old 06-01-2012, 04:27 PM   #1
TestPoint
Board Member
 
TestPoint's Avatar
 
Join Date: Jul 2009
Location: Ellijay
Default '81 262c B28F CI fuel system issue

I am trying to get an '81 Bertone B28F running and everything keeps coming back to the fuel pump relay . . . or the ballast resistors.

Replaced the FP relay with an used one and get exactly the same issue.

The FP relay operates in START, pumps run, engine starts. Engine starts instantly but when you release the key to RUN it quits instantly. Relay releases in RUN. Measured resistance across the resistors and on my precision Harbor Freight VOM at 1.8 ohm. Should be 1.0 ohm. This causes the voltage at the coil to be 4.7v rather than what I expect should be 6.0v.

The problem does not appear to be the ignition switch itself as I continue to measure 12v on fuse #11, 12 and 13 which feeds the FP relay winding and the ignition system. Obviously, the ignition system functions in START so I would expect it to in RUN unless that 4.7v is below reliable operation of the coil . Here is the schematic for the ignition switch/fuel pump relay.




Here is the schematic displaying the ignition system in START and RUN position. The difference being that voltage is dropped across one 0.5 ohm resistor in START and over two 0.5 ohm resistors in RUN. Mine, however, measures a total of 1.8 ohms. I would just change them out but they are a little scarce out here in the woods.



I opened the original FP relay and found a postage stamp sized circuit board which, I assume, is driven by the lead from the coil negative post. That signal would be a pulsed ground from the Ignition Electronic Module I believe.

Comments and suggestions appreciated and I would like to know how the ignition dwell signal interacts with the RUN B+ on the relay winding unless someone knows what the solution is then I don't care.

[For anyone exploring this thread as an educational experience here is an excellent explanation of the Bosch CI fuel system thanks to vlvman.]

http://www.volvowiringdiagrams.com/v...0injection.pdf

Last edited by TestPoint; 05-14-2014 at 07:41 PM..
TestPoint is online now   Reply With Quote
Old 06-01-2012, 05:36 PM   #2
dl242gt
Happy playing the blues
 
dl242gt's Avatar
 
Join Date: Jun 2002
Location: S NJ, a suburb of Phila.
Default

Yes, your ballast resistor is bad. It is almost twice the resistance it should be. Of course I would want to double check it with a more accurate meter if you don't trust your harbor freight one. Many times the resistance gets a bit higher as these ballast resistors get hot. So it might be even more resistance when it gets hot from current flowing through it.

Use only Bosch resistors. Personally, I had a very bad experience trying to use an aftermarket resistor on my B21FT.
__________________
Dave,
1982 242 turbo. 340k miles. Good stuff and lots of rust.
1993 245 Classic, 420k miles, enem V15. IPD bars and chassis braces. Simons sport exhaust from Scandix. sbabbs ezk chip. Been a good road warrior. Genuine Volvo rebuilt leaky M47.
dl242gt is offline   Reply With Quote
Old 06-01-2012, 05:54 PM   #3
JohnLane
Board Member
 
Join Date: Nov 2002
Location: Northern Washington
Default

There you are!

A fellow in 'For Sale' has a Lambda brain for your car available for adoption for $15.00. Dunno if you need it.

OP just where in the hell are you?

As for the Ballast resistor........ Bypass it for testing. The ignition system cares not during testing if it gets full voltage. Problem goes away by bypassing it? We know where to look.
__________________
Overkill is consistently more fun.
JohnLane is offline   Reply With Quote
Old 06-01-2012, 06:52 PM   #4
TestPoint
Board Member
 
TestPoint's Avatar
 
Join Date: Jul 2009
Location: Ellijay
Default

Hi John, I'm in Ellijay . . . only one in the world. Actually, in Cherry Log, a suburb of Ellijay, apple capital of the north Georgia Mountains.

I tried jumping the resistor with a clip-on lead and that got the coil voltage up to 5.0v. A couple feet of 16ga wire has more resistance than the 0.5 ohm resistors. Then soldered in a couple Radio Shack 1.0 ohm 10w ceramic resistors in parallel and that got the voltage up to 5.33v.

Guess I will pull it all apart and just tie everything together and see what happens.

My gut keeps telling me that something is not working correctly with the FP relay winding control. The relay 'holds over' about a second after START is released to RUN. Wish I knew what the Ignition Module ground 'dwell' did to control the relay. B+ is sitting on the 15 pin (blue/red) winding lead in both START and RUN but the relay releases as if the internal relay circuit is not seeing the ignition ground 'dwell'. That 'dwell' must be present from the Ignition Module since the coil is firing and engine running in START and the IM is powered from fuse #11 in both positions.

Last edited by TestPoint; 02-13-2013 at 05:44 PM..
TestPoint is online now   Reply With Quote
Old 06-01-2012, 07:01 PM   #5
TestPoint
Board Member
 
TestPoint's Avatar
 
Join Date: Jul 2009
Location: Ellijay
Default

Searched the 'For Sale' forum without finding the Lambda Module you mentioned. Got a link?
TestPoint is online now   Reply With Quote
Old 06-01-2012, 07:34 PM   #6
TestPoint
Board Member
 
TestPoint's Avatar
 
Join Date: Jul 2009
Location: Ellijay
Default No Cigar

Completely eliminated the ballast resistor. Getting over 11v to the coil. Same situation. Starts in START, dies in RUN. FP relay releases in RUN.

John, you had mentioned that the engine is starting on the cold start injector.

Forgot to mention that the Frequency Valve is not buzzing in this post but until I can get the FP relay to stay operated in RUN chasing pressure seems like a waste of time.

http://forums.turbobricks.com/showthread.php?t=250257

http://forums.turbobricks.com/showthread.php?t=256460
TestPoint is online now   Reply With Quote
Old 06-01-2012, 08:03 PM   #7
nel621
Board Member
 
Join Date: Apr 2009
Default

http://forums.turbobricks.com/showthread.php?t=258723
nel621 is offline   Reply With Quote
Old 06-01-2012, 08:11 PM   #8
nel621
Board Member
 
Join Date: Apr 2009
Default

Here is the PVR computer JohnLane talked about.I don't think this is your problem.I had an 80 262c a while ago with a similar problem.The problem was 2 fold.The ballast resistor was faulty but also the brain box [grey box on fender in engine compartment]was also at fault.Although I tried many things to repair it I ultimately took it to a "friend' who worked for Volvo and then opened his shop.He knew enough about these cars to quickly pinpoint and repair it.Lucky for me he had a spare brain box in his shop[no cost to me].Good luck.
nel621 is offline   Reply With Quote
Old 06-01-2012, 08:26 PM   #9
TestPoint
Board Member
 
TestPoint's Avatar
 
Join Date: Jul 2009
Location: Ellijay
Default

I got my training in electronics in the tube era. Discreet component circuit boards are no problem . . . if only I had a schematic to work with.
TestPoint is online now   Reply With Quote
Old 06-01-2012, 08:58 PM   #10
nel621
Board Member
 
Join Date: Apr 2009
Default

You may be losing your signal in the ignition electronic module.But as you mentioned there are no schematics from Volvo to help you trace the faults.Even the "Green Books' lack this info.I could only suggest finding a known good module and swapping it in to see if it solves your problem.Using the link above you may want to contact "suped." to see if he has the ignition module from the Bertone he parted.IIRC the car was running and the part should be the same even though it was from a 79.
nel621 is offline   Reply With Quote
Old 06-01-2012, 11:53 PM   #11
JohnLane
Board Member
 
Join Date: Nov 2002
Location: Northern Washington
Default

Hey check that you have a 'Flashing' signal to the fuel pump relay at all times with the engine running.... This is the ignition signal and is supposed to be how the fuel pump relay is turned on.
JohnLane is offline   Reply With Quote
Old 06-02-2012, 06:12 AM   #12
TestPoint
Board Member
 
TestPoint's Avatar
 
Join Date: Jul 2009
Location: Ellijay
Default

OK guys, help me understand the FP relay operation please.

It gets B+ from the ignition switch in both START and RUN but does not operate without a signal from the ignition module? That signal would be a pulsing (flashing?)(dwell) ground?

I get FP relay operation in START but not in RUN.

Completely bypassed ballast resistor and that did not change anything.
TestPoint is online now   Reply With Quote
Old 06-02-2012, 07:34 AM   #13
TestPoint
Board Member
 
TestPoint's Avatar
 
Join Date: Jul 2009
Location: Ellijay
Default

Had a cup of coffee and been thinking. Maybe the relay operation is correct because the injectors are not injecting.
Quote:
John, you had mentioned that the engine is starting on the cold start injector.
Suspect that Advance Auto Parts is not going to have a fuel pressure gauge suitable for the CI system. I have a gauge and one of the large banjo connectors.

Is there a correct place to measure the pressure using the large connector?

Yeah, I know, I have the book and will go look it up in a few minutes.
TestPoint is online now   Reply With Quote
Old 06-02-2012, 11:08 AM   #14
dl242gt
Happy playing the blues
 
dl242gt's Avatar
 
Join Date: Jun 2002
Location: S NJ, a suburb of Phila.
Default

the signal is actually from the ignition coil. NOT the ignition box. There should be a wire connection for the coil negative terminal 1 and it runs to the fuel pump relay. It is simply the same rpm signal a tach would use to let the fuel pump relay know the engine is rotating and the fuel can then flow. It also tells the fuel system that the spark is working. On the 240 this is a white/red wire from the coil to the fuel pump relay. You can put a test light on it and it should flash as John mentioned. Without an rpm signal the fuel pump relay will shut off.
dl242gt is offline   Reply With Quote
Old 06-02-2012, 11:55 AM   #15
TestPoint
Board Member
 
TestPoint's Avatar
 
Join Date: Jul 2009
Location: Ellijay
Default

I guess that is what is happening. The FP relay operates with the starter rotation and continues until the engine quits turning a second after you release the key to the RUN position.

Think I will pull the easiest injector and see if it is spraying. If not begin testing fuel pressure. I know the new pumps will fill a container quickly but have not measured pressure.

I have tested continuity and voltage to the Lambda Control Module and everything works per the green book test sequence but the Frequency Valve does not vibrate.

Don't think I have posted on this thread that the in-tank pump, pressure pump and filter are new. Fuel distributor rebuilt by JayTan Ind.

My white/red wire is spliced/connected somewhere before the coil as there is only one wire there.
TestPoint is online now   Reply With Quote
Old 06-02-2012, 12:04 PM   #16
JohnLane
Board Member
 
Join Date: Nov 2002
Location: Northern Washington
Default

Place to check fuel pressure is at the top of the cold start injector.

Pull one of the front fuel injectors and plug the hole..... Turn the injector so that it points up.... You'll easily see the spray.

With fuel pump operation you can just push down on the ariflowsensor plate and injectors will deliver fuel.

You can 'jump' the fuel pump relay to bypass it to make for fuel pump operation and frequency valve operation to get things set up.

White/Red wire may spliced into an aftermarket alarm that is making life hell 15 years later.
JohnLane is offline   Reply With Quote
Old 06-02-2012, 12:17 PM   #17
Lord_Athlon
Chuckie Blows
 
Lord_Athlon's Avatar
 
Join Date: May 2003
Location: Hillary's Emails
Default

Swap the ignition switch
__________________
Quote:
Originally Posted by RvolvoR View Post
simple...just throw the redblock in the trash and install, well, almost anything modern

Quote:
Originally Posted by Harlard View Post
Yet Asher here went with...
Lord_Athlon is offline   Reply With Quote
Old 06-02-2012, 08:56 PM   #18
TestPoint
Board Member
 
TestPoint's Avatar
 
Join Date: Jul 2009
Location: Ellijay
Default

Thanks for the thought but the ignition switch is delivering 12v to the relay in both START and RUN.

Got a big box in today with all the things I needed to finish the front brake rebuild. The car now has newly turned rotors, new calipers, new pads, new flex hoses and new lug nut studs . . . and a new master cylinder. New lug nuts arrive Monday . . . see below.

While the wheels are correct Volvo optional wheels they have created a problem. The 26 year old tires, with about 90% of tread remaining, were 205-65 15 and I ordered and installed the same sized tires. I also found 1/4" spacers behind the wheels that I had intended to do away with but now I know why they were there . . . the tires on these 7" wheels caused the tires to rub the struts. I also found that the lug nuts, with the spacers installed, only had about 3/16" of thread engaged on the studs. That wasn't going to do.

Tried to find longer lug nut studs to solve the issue but ran into the problem that the Volvo has an unique Knurl (yes, a new word to me also) of 0.640" that only comes in one length, 2 5/8", anywhere in this dimension.

I think I have found correct lug nuts that are 0.3" longer than the ones on the car. They are due in Monday and we will see.

The point of all this discussion is that I am through for the day and will get back to the START/fuel issue tomorrow.
TestPoint is online now   Reply With Quote
Old 06-04-2012, 10:41 AM   #19
JohnLane
Board Member
 
Join Date: Nov 2002
Location: Northern Washington
Default

OP be damned sure that you are getting 1/2" or so of threads holding that wheel on!

I've experienced the excitement of a wheel taking leave while driving I wouldn't wish that on you or anyone else!

I've broken wheelstuds too. Not to worry.... Your stock six isn't doing that... But it can should you wish for it
JohnLane is offline   Reply With Quote
Old 06-04-2012, 01:57 PM   #20
TestPoint
Board Member
 
TestPoint's Avatar
 
Join Date: Jul 2009
Location: Ellijay
Default

I sure wasn't going to use the lug nuts with that little contact with the stud! But apparently the car was used for some time like that. Just picked up the longer bolts but am now concerned that they are too long. We'll see this afternoon.
TestPoint is online now   Reply With Quote
Old 06-04-2012, 07:07 PM   #21
TestPoint
Board Member
 
TestPoint's Avatar
 
Join Date: Jul 2009
Location: Ellijay
Default Please forgive the incorrect information

The front lug nuts were, indeed, only on the studs about 3/16" but the new lug bolts were about 3/16" too long.

The incorrect information is that it was not the struts that the tires were rubbing on but the JACK STANDS. Removed the spacers . . . and the jack stands . . . and the 2 5/8" lug bolts now fit. That doesn't quite give be a half inch of thread but close enough for folk music.

Also had a flash of adequacy concerning the lug bolts . . . they were never going to work with the spare tire. Bought a set of simple 1/2"x20 lug nuts and threw them into the TOOL KIT. Yes, I have the full original Volvo took kit.

If only the engine ran!

New (used) Lambda Sond module and some bits to make a fuel pressure test device should be here by mid week.
TestPoint is online now   Reply With Quote
Old 06-05-2012, 07:52 PM   #22
TestPoint
Board Member
 
TestPoint's Avatar
 
Join Date: Jul 2009
Location: Ellijay
Default Sorry about the switch to wheels

I did get to remove the spacers. The rubbing turned out to be the jack stands. I had moved them as close to the tires as possible and sure enough, without the spacers they rubbed the tires. Dummy!

Back to the CI fuel system.

Removed the front left injector. Couple of comments;

My seal were not all that hard probably because this 31 year old car only had 25k miles. I could dent it with a finger nail. I have a new set because everyone said they would be hard and non functional but decided not to replace them at this point.

After jumping the FP relay and moving the air flow plate I get a decent fuel spray!!!!

Probably could use a couple gallons of SeaFoam injector cleaner over several tanks of gas.

After jumping the FP relay and with pumps running tested the 'SYSTEM RELAY'. I am not getting B+ on the blue lead (86) from the FP relay on both the original and used FP relay. Guess I will go clean that contact on one.

Really proud that I get injector function verified.

In case you haven't noticed I have a life beyond restoring this car so please forgive the days that go by without updates.

Last edited by TestPoint; 06-05-2012 at 09:22 PM..
TestPoint is online now   Reply With Quote
Old 06-05-2012, 08:37 PM   #23
JohnLane
Board Member
 
Join Date: Nov 2002
Location: Northern Washington
Default

Quote:
Originally Posted by TestPoint View Post
In case you haven't noticed I have a life beyond restoring this car so please forgive the days that go by without updates.
You fool no-one We all know that you only arrive here once you are at your wit's end and are ready to once again light the car on fire......

This may take days which explains the gaps between updates.

Blue wire no gots power? I thought that the blue one came straight from the ignition switch....... I could be wrong. Hmmm.....
JohnLane is offline   Reply With Quote
Old 06-05-2012, 08:39 PM   #24
TestPoint
Board Member
 
TestPoint's Avatar
 
Join Date: Jul 2009
Location: Ellijay
Default

Removed the cover from the original fuel pump relay and sure enough, had erratic reading on one of the contacts. Cleaned with 600 grit w/d paper and now get positive connections. Too late, too many olives to put back in the car.

Tomorrow, tomorrow . . . .
TestPoint is online now   Reply With Quote
Old 06-05-2012, 09:11 PM   #25
TestPoint
Board Member
 
TestPoint's Avatar
 
Join Date: Jul 2009
Location: Ellijay
Default

My wits end on this car is only mm away. I have been working on motorcycles and cars for 55 years and this one is killing me.

Went back to the schematic and found that the Green Book schematic for the B28F did not have wire color codes on it. Backing up to the B21F schematic, which is very similar that page has color codes. That is what I am relying on.

Here is what I think life looks like:


Last edited by TestPoint; 06-13-2012 at 04:26 AM..
TestPoint is online now   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


All times are GMT -4. The time now is 09:57 PM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2019, vBulletin Solutions Inc.