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Discussion Starter · #1 ·
So I have an issue that I've been trying to diagnose for a few weeks now, and I'm about out of ideas.

Over the winter, I got my 67 P1800 running with the help of 142guy and Ron Kwas: https://forums.swedespeed.com/showthread.php?584357
During that whole process, I removed all the gas from the car and put in 2 gallons of fresh gas (I think it was 87 Octane). The car ran well the few times I took it out for short drives around the neighborhood.
Then about a month ago, I was troubleshooting some issues with my fuel gauge and went to put more gas in to see if the needle moved. I added 5-6 gallons of Premium (I think it was 93 Octane).

About 3-4 weeks later, I went to take the car to a welding shop, and got about a mile from my house and the car wouldn't accelerate any more. If I let it idle, it idled ok, it never died. If I revved the engine in neutral, it would rev ok (but not great), but once in gear, the car would sputter and barely move. I could let it cool for 15 minutes, drive it 1/4 mile before it began to sputter again. I repeated this 4 times to get it home.

I dove in to sw-em and my SU carb book to learn about how to adjust the carbs. I also made it to Carlisle where I talked to about 3-4 Volvo owners with SU carbs and got some ideas. I re-routed my fuel line to ensure it wasn't getting too hot. No amount of making the mix leaner or richer seemed to help. The choke appears to be adjusted right where it should be, and its fully off when the knob is in.

As the car was idling, if I lifted the dashpot with a finger on the front carb, nothing happened at all. If I lifted it on the rear carb, the engine would slow and eventually die. I think the expected behavior is that lifting either dashpot during idle should slow the car. But this is telling me that the car is likely running on just one carb. Does that sound right?

When the engine is running, the gas in my clear fuel filter is clear. Once I shut off the engine, the fuel begins to turn orange. By the evening, it will be slightly orange, and by the next day, a bright orange. My first thought was rust in the gas tank. But then it would be orange when it entered the filter, and it is not. The filter was also recently cleaned.

So I took the carbs apart two days after the last time I ran it and found something odd. The fuel in one of the float bowls is orange (and a bit mucky) and the other is clear.


So I gave the float bowls a good cleaning, took out the jets and blasted air through them, re-assembled and drove it with the same result, but now I can't even make it 1/4 mile before the car sputters. Again, after sitting a day, the fuel filter looks like this:



Again, I was able to let it idle and tried my experiment with lifting the dashpots by finger to see what happens, and I got the same result, but on opposite carbs. Lifting the front carb slowed (and eventually stalled) the engine, the rear carb had no measurable effect.

When googling for "orange fuel problems", I found a lot of boaters have this issue with ethanol fuel attracting and bonding with water. I'm now suspecting that I either got bad gas, or the gas went bad for sitting for a month. I added some Sta-Bil 360 in the tank last night, and will see if that changes anything today when I get home from work. I'm also thinking about adding a water separator filter, as many of the boaters with nearly identical symptoms have had good luck with them. Here's the one I've ordered: https://www.amazon.com/gp/product/B072X8CSHL

Has anyone else experienced similar issues with E85 or other ethanol variants in their B18s?
 

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So I have an issue that I've been trying to diagnose for a few weeks now, and I'm about out of ideas.

Over the winter, I got my 67 P1800 running with the help of 142guy and Ron Kwas: https://forums.swedespeed.com/showthread.php?584357
During that whole process, I removed all the gas from the car and put in 2 gallons of fresh gas (I think it was 87 Octane). The car ran well the few times I took it out for short drives around the neighborhood.
Then about a month ago, I was troubleshooting some issues with my fuel gauge and went to put more gas in to see if the needle moved. I added 5-6 gallons of Premium (I think it was 93 Octane).

About 3-4 weeks later, I went to take the car to a welding shop, and got about a mile from my house and the car wouldn't accelerate any more. If I let it idle, it idled ok, it never died. If I revved the engine in neutral, it would rev ok (but not great), but once in gear, the car would sputter and barely move. I could let it cool for 15 minutes, drive it 1/4 mile before it began to sputter again. I repeated this 4 times to get it home.

I dove in to sw-em and my SU carb book to learn about how to adjust the carbs. I also made it to Carlisle where I talked to about 3-4 Volvo owners with SU carbs and got some ideas. I re-routed my fuel line to ensure it wasn't getting too hot. No amount of making the mix leaner or richer seemed to help. The choke appears to be adjusted right where it should be, and its fully off when the knob is in.

As the car was idling, if I lifted the dashpot with a finger on the front carb, nothing happened at all. If I lifted it on the rear carb, the engine would slow and eventually die. I think the expected behavior is that lifting either dashpot during idle should slow the car. But this is telling me that the car is likely running on just one carb. Does that sound right?

When the engine is running, the gas in my clear fuel filter is clear. Once I shut off the engine, the fuel begins to turn orange. By the evening, it will be slightly orange, and by the next day, a bright orange. My first thought was rust in the gas tank. But then it would be orange when it entered the filter, and it is not. The filter was also recently cleaned.

So I took the carbs apart two days after the last time I ran it and found something odd. The fuel in one of the float bowls is orange (and a bit mucky) and the other is clear.


So I gave the float bowls a good cleaning, took out the jets and blasted air through them, re-assembled and drove it with the same result, but now I can't even make it 1/4 mile before the car sputters. Again, after sitting a day, the fuel filter looks like this:



Again, I was able to let it idle and tried my experiment with lifting the dashpots by finger to see what happens, and I got the same result, but on opposite carbs. Lifting the front carb slowed (and eventually stalled) the engine, the rear carb had no measurable effect.

When googling for "orange fuel problems", I found a lot of boaters have this issue with ethanol fuel attracting and bonding with water. I'm now suspecting that I either got bad gas, or the gas went bad for sitting for a month. I added some Sta-Bil 360 in the tank last night, and will see if that changes anything today when I get home from work. I'm also thinking about adding a water separator filter, as many of the boaters with nearly identical symptoms have had good luck with them. Here's the one I've ordered: https://www.amazon.com/gp/product/B072X8CSHL

Has anyone else experienced similar issues with E85 or other ethanol variants in their B18s?
I have a 65' Porsche 356. (doesn't have to be a B18 engine)
I have "never" had any problems with ethanol fuel.
I store my car in November and bring it back out in May for the summer.
I never use Sta-Bil and never had a fuel related problem in starting.
Did you ever have your fuel tank cleaned and coated? Never had orange fuel so I don't know what that is all about. (maybe coating coming off if it was coated)?????
Forget the water separator unless you have a ton of water in your tank. (you would then drain and refill anyway)
I always keep my tank full to avoid condensation.
I would be willing to bet you have a fuel pump and or carb problem.
People always blame ethanol fuel when they can't find the real problem.
Good luck!
 

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RJ8;

"...about a mile from my house and the car wouldn't accelerate any more. If I let it idle, it idled ok..."...an engine that idles but does not run under load sure sounds sounds like a fuel feed issue...idle takes very little fuel, but a loaded working engine needs a lot more, so check for partially blocked line, or clogged filter, or clogged Jet Supply Lines...

"... lifted the dashpot with a finger on the front carb, nothing happened at all. If I lifted it on the rear carb, the engine would slow and eventually die" ...lifting the Dashpot without moving throttle essentially just changes the idle mixture (leaner)...lifting it higher than with lifting pin kills the venturi and leans it out totally, so I would expect it to die...

Fact that front and rear carb are doing different things, as well as fuel in them looking totally different tells us something, so it is up to you to find the difference! ...check supply tube between two carbs for restriction...

Good Hunting!
 

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I really know zip about SU carbs other than they are kind of like the Keihin CV carbs that were on the Honda 750 F that I used to have. That said, I vote with Ron that your problem certainly sounds like fuel starvation. You might have a fuel pump problem. If you have a fuel pressure gauge or access to one, checking fuel pressure might give you an indication as to what is going on - Volvo greenbook specifies 1.55 - 3.55 psi for the 140. If you did the new pump thing, did you get the appropriate spacer that fits between the pump and the block? There was a thread in the 140 forum where a member was having pump issues and one of the problems (amongst many) was a spacer issue.

Ethanol blended gas exposed to moisture can form an emulsion which separates from the hydrocarbon part of the mixture. Typically, you need a bought of nasty cold weather for the water and ethanol to come out of suspension in the fuel. The emulsion looks milky / gooey / other unflattering adjectives. An engine will not run on the emulsion if it gets sucked up so that does not sound like your start and then die once moving problem. If you got it started and sucked up some emulsion I think you would be dead - no restarting. Conventional gasoline exposed to oxygen will form varnishes and turn a darker amber color. The consensus shelf life on sealed gasoline or exposed gasoline without stabilizer is typically 6 months or less at which point deterioration starts to become measurable. Deteriorated gasoline results in poor operation, not your start and then die once moving problem. There is no E85 where I live so I have no experience with how it deteriorates and what color it turns.

Check the tank venting. If the air inlet to the fuel tank is blocked or significantly obstructed mechanical fuel pumps really 'suck' at working with a negative suction head. Easy test is remove the gas cap and see if the problem goes away.
 

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RJ8;

Good info from 142G...to that I'd like to just add that an apparent Fuel Pump problem might be caused by a restriction (by contamination collected in a line or filter)...and having thought about it a bit more...the two carb bowls are (or should be) essentially connected by the short hose...if fuel in them looks that different, this is a big clue...as 142G says, old fuel which has absorbed moisture will look orange and cloudy...this suggests to me, that fuel is not getting drawn from that bowl and consumed, rather sitting there deteriorating...if this is the bowl on carb which is not doing anything ("...if I lifted the dashpot with a finger on the front carb, nothing happened at all. ") I'd check if throttle linkage on that carb is slipping, or not tightened or connected at all, causing that carb, including any fuel in it, to be just along for the ride, but functionally out of the picture...

Good Hunting!
 

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Discussion Starter · #7 ·
Awesome advice - thanks.

So this past weekend when I took the carbs apart, I blew compressed air through all hoses and jets in both directions. I too thought something was clogging, but nothing seemed restricted.

I do have the fuel pump spacer. I re-used the one that was on the car.

I'd given the throttle linkage a good check when I took the carbs apart. I'll re-check it to be sure.

Based on what you've both said I'm going to try these things this weekend (in this order).
1. Check to see if the bowls have similar colored gas now. I suspect they might. If not, it's going to make me re-think the items below.
3. Running the car with the gas cap open. This actually makes a lot of sense to me that it could be the issue.
3. Try the old fuel pump. I'd replaced the one on the car simply because I wanted to refresh all the components in the fuel/spark systems. But to my knowledge, the old pump worked just fine.
4. Install the new filter. I'd wanted to put a filter between the tank and the pump anyway, and the fact it's a water-separator filter is just added protection.

Thanks!!
 

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Do a little checking on the spacer issue because I had the impression that the original spacers and new spacer & new pump were not a mix and match. I could be mistaken. The easy check would be to connect a temporary hose to the pump output, direct into a catch can and have somebody crank the motor for a few seconds. If fuel delivery looks good then the pump may not be the issue. However, lack of flow could also be a suction side fuel system blockage.
 

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Discussion Starter · #9 ·
Do a little checking on the spacer issue because I had the impression that the original spacers and new spacer & new pump were not a mix and match.
I will. The odd thing is that it ran well before the previous fill up. I drove a couple miles around the neighborhood without issue (including some nice acceleration). That fact usually leads me to rule out a few things, including likely the spacer as it would have presented earlier.
 

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Discussion Starter · #10 ·
Ok, so here's what happened this weekend.

First thing I tried was driving with the gas cap flap off. Based on the symptoms, I really thought this was it. I'd recently POR15'd the underside and thought maybe I'd clogged the vent. But no. Got 1/4 mile and symptoms developed, I turned around and headed back.

Opened the float bowls, rear one was orange, front one clear. Then realized last week I blew air through the hoses, but not through the caps on the fuel bowls. Tried that, but they were clean, and symptoms persisted.

Let the engine idle, tried lifting the dashpots, again, rear one stalls the engine. Based on what's in the SU book, that means its too lean, so I richen the mix, and keep going richer and richer. Thing is, I needed to do about 3-4 full turns before I got the desired result (lift the dashpot, get a blip in acceleration). When I rebuilt the carbs before (and reset them last week), I'd followed the procedure of raising the jets to be flush with their mount, then 2 complete turns (12 sides) backed off. This is what I'd used as a starting point. The idea that one jet could need to be set so different (18-24 sides!) just didn't seen plausible to me. But lo and behold, I drove about 3/4 mile. The car wasn't running perfect, but it was running.

So now I'm trying to figure out why it ran ok before, and not now.

Another interesting thing I discovered:
Here is the fuel pump I bought: https://www.ebay.com/itm/171973711390
As you can see, there are screws where it can be opened. I wrote to the seller to ask if it could be taken apart without damaging it, and put back together without specialty tools. He asked what the issue was and I told him I have acceleration issues that may or may not be due to E85. He said that another customer informed him that E85 will eat these pumps. But then in the next mail, he said that he's sold 200 of them without issue. But he did offer to send me a replacement at no charge. I declined. I said if the issue was the fuel pump being eaten by E85, the next one would last as long. There is no pure gas sold within 1.5 hours of me.

So on my 3/4 mile drive, the only reason I stopped was because the GEN light was on. I googled the issue and it took me to SW-EM (as it always does :). I liked the description that the current set up is tricky for advanced mechanics, and baffling for the DIYer. So, I'd bought a GM style alternator months ago (the one recommended by Ron on his page) but never installed it, and figured now was the time to get it in there. Turns out, someone had replaced the OE Bosch unit with a Motorola one at some point, and the Motorola one needed a bracket, so there is a bracket on there already (a different style than what Ron sells). I need to go bolt shopping tomorrow as I'm missing one critical bolt, but I am 99% sure this bracket will work. If not, Ron, I'll be placing an order for your bracket.

I have no idea how long that GEN light had been on. I don't recall seeing it on before, but that doesn't mean it wasn't. I was wondering if the generator was fried, if that could produce similar symptoms (car idles ok off the battery, but doesn't have enough power to support acceleration). But then I thought that can't be it. Otherwise the symptoms would not improve when I let the car sit for a while (and they do improve).
 

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Discussion Starter · #11 ·
Looks like I got some of my terms wrong. I'm running the standard available gas from Exxon, which I guess is E10 or E15. I thought the E## designation was to signify how much gas is in there, with the "e" being the remainder. But I see that E85 is actually 85% ethanol, which I certainly didn't put in. :)
 

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RJ8;

Lifting the carb Dashpot is not a test I would perform while there are still big differences in the apparent operation of the two carbs, and I still can't get around the difference in appearance of fuel in the two bowls " rear one was orange, front one clear."...I still have the thought that fuel is not being drawn from the rear carb...with Air Filters removed and by blipping Throttle, you should, aided by a light, be able to see fuel is being drawn from Venturi of rear Carb, and atomized. I'd clean orange fuel from rear Fuelbowl, taking note of what has been collected in the Bowlsump, then backblow air or carb cleaner with a snoozle, from Venturi through Venturi Supply Tube, to verify this path is clear...if that Carb's Throttle is opening (check Linkage!), that Carb should be contributing mixture, and I wouldn't expect its fuel to look different...or is orangeness caused by sediment in Bowlsump...?

If Fuel Pump is in doubt, if it is still moving fuel at all, it may be sending particulate or gummy contamination downstream as non-return valves or membrane deteriorate, and that may very well be causing blockage, and complicated issues with whacky symptoms, and you certainly have those...once both non-return valves fail, Pump will no longer be able to move fuel...

AMP Indicator ON is clearly a completely separate issue covered in the SW-EM Tech Article...I suggest sorting the carb/fuel issues before moving on to this (one crisis at a time please!)...you don't need a functioning Chg Sys to sort the Carbs...you could sort those strictly running off Battery power...!

...and before even thinking of replacing Alt, you MUST FIRST ascertain if reason is Charge Sys OR Fuse 1 (or associated connections open) failure...see tech article. If your current setup has a Bosch Alt, it will NOT fit a Delco without changes...see: http://www.sw-em.com/altkit_additional.htm

Good Hunting!
 

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Once again I line up behind Ron on the fuel issues. The fact that you have different color 'liquids' in the float bowls still seems like a fuel delivery problem.

With respect to the fact that enriching fuel mix seems to improve the operation of the carb / engine. Again, I am no SU wiz; but, overall fuel mixture is set by the fuel level in the float bowl. If the operating fuel level is above the factory specified level the carb will run rich and if the fuel level is below spec the carb will run lean. If you are having a fuel delivery problem to the carb that is resulting in low float bowl levels the carb will run lean. Cranking up the fuel mix on the carbs may only be compensating for the fact that the fuel levels in the float bowls may not be correct.
 

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Discussion Starter · #14 ·
Hey Ron -

While I agree that the issue is the carbs, the alternator upgrade has been on my to-do list for a while and that box on the shelf has been taunting me for months. By the time I'd read your reply, the old one was already out. That said, my Motorola mount wont work for the Delco, and I'll need one of your mounts to get the new one in. I'd sent you an email yesterday to the address on your site. Did you get it?
 

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My 1966 P1800 runs kind of similarly. For some reason after running a lot it starts stumbling. Like on my 3rd drive of 4-5 miles on any day, it will start - never before.

What happens:
under 4,000 rpm - runs perfect
over 4,000 rpm, it stumbles. Like water in the gas or running out of gas or similar.

Make sure you post what your fix is. I will do the same.

I did take the gas cap off - no change. It is not water in the tank. Gas pump is about a year old. Runs and starts perfectly otherwise.

I thought maybe it was too lean, I have tried choking it on several occasions, no change. I was thinking of getting an in-line gas pressure regulator.
 

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Update: Rick has installed the SW-EM Alt kit and the Delco Alt he installed is working well. Feedback from Rick for anyone interested...it's the most recent feedback here: https://www.sw-em.com/feedback_and_testamonials.htm

Breaker; Misfire above 4000RPM (if this is a continuous condition) can be due to fuel requirement which is high at that RPM (Fuel demand is also Load dependent obviously, so I'd run it up a continuous hill to see if stumble occurs at a lower RPM, confirming a fuel supply issue)...otherwise, there might be an ignition issue...state configuration and condition of ignition...you might want to start a new thread for this...

Cheers
 

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Thanks Ron!

I will try that. I have what looks like an original coil that is sunk into the firewall (takes a licking but keeps on ticking). The cap, wires, and plugs are less than 2 years old. High-quality replacements for OEM is all that I have used.

Thinking about it, I really do see the point about checking on a hill/ on load at under 4k rpm. That would let me rule out the ignition system not being able to keep up at those rpms under those conditions.

I do think it varies - but I will recheck.
 

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Discussion Starter · #18 ·
Hey Breaker - I haven't had time to get back in to my carbs issue. A few missed emails between Ron and myself delayed the alternator work, so..... of course I decided to start on something else, and did some needed welding.... which required the interior to come out.... and then as long as the interior was out I ran some wires for the stereo..... which of course meant installing some of those components. So as it usually goes, I get wayyyy sidetracked on tangential work. But as of Sunday, that work is all complete and I'm back to diagnosing the carbs. I'm going to double check a few of the things on Ron's page and posts, but if it's still temperamental I may just take it to a vintage Saab/Volvo specialist I just learned about. I'm eager to drive the car, and my lack of time to put in to it means summer may be over by the time I get this sorted. We'll see.
 

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Discussion Starter · #19 ·
Ok, so here’s where I am:

Double checked everything from SW-EM, and all screws and cables look to be in the right place and all parts move as they should. Car still starts and idles just fine. Decided to take it out for a drive to replicate symptoms. Whereas before I could drive 2 blocks (2-ish minutes) I took a 7-8-ish minute drive before any sputtering started. I was wondering if the outdoor temps had anything to do with it. Then, I had another theory. What if something in the gas line was going from the tank to the carbs. The longer the car sat, the more it settled and the longer it would take to reach the carbs? So I decided to test that theory by driving it the very next day to see if my drive times returned to 2-minutes. I went for a 15 minute drive and no sputtering at all (only stopped because I had an appointment). So, that rules out my theory, but the car is running better.  However, I still have an issue where (with the air cleaners off) if I lift the front dashpot, the idle fluctuates slightly, but the car still runs. If I lift the rear dashpot, the car stalls immediately. So I’m not sure which carb is giving the expected reaction, but one of them is still not working right.

I’ve decided to take it to a mechanic next week. Even if I did solve the issue, I think there is value in having an experienced mechanic tune it properly. So let’s just get it on the road.
 

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Discussion Starter · #20 ·
So, I got 'er runnin!

I called two mechanics near me that work on these cars, both of which didn't have the time to look at it.

So, here's what I did. The carb giving me issues was the second one in line. I checked all the passages and all seemed to be in order, but I still wondered if fuel wasn't making it past the first carb.

So I did this hackery:


It didn't make it run perfect, but it did run better. I'd say it was just enough of an improvement where it was in range of being able to be tuned to run. I played with the mixture nuts and idle screws until it finally ran (the mixture nut on the rear carb is still several turns below the front one). It now runs smooth (needs choke on start up, but runs fine when warm), but it smokes and smells. I'm certain it's running rich. I have a wideband O2 sensor and gauge I bought but haven't installed yet. I think now is the time. I need to get it leaned out but still running right. Then I need to try to put the fuel hose back to it's original configuration and see if I can get it to run with it that way. If not, I guess I try new float bowl lids???

Anyway, super excited about having it running. I got it state inspected this morning and drove it in to work.
 
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