Volvo P1800ES...kinda

In reply to Eurotrash_Ranch :

Don't think anyone is going to sleep past the exhaust note

But yeah...big local  Volvo meet in July. Going to park it with the hood closed and stand back to see if anyone notices.

Pete

NOHOME said:

In reply to Ian F :

The door panels will be off at least a few times. I have an issue with a weak spring in the DS that makes the outside button flaky. The vinyl itslef is in good shape, but I have considered making new doorcard backers.

Pete

I'm not sure it's a spring so much as the adjustment between the handle button and the latch mechanism.  Both mine and my ex's car have needed fiddling to keep working right. Especially the passenger side, for some reason. 

With the hood down, the car will definitely fly under the radar a bit. From a distance, the main indicator something is "off" is the 4 lug wheels.

OK, waving the white flag here, need thoughts on weird engine problem:

 The engine starts and idles ok.  You would not think anything is wrong. .The issue is that when I open the throttle, the engine is sluggish to respond. Then, if I try to hold the throttle at a steady high rpm point, say 3500 rpm, the vacuum falls to below five inches of Hg and the rpms drop at the same time.

Noticed the same issue when I started the engine with a carburetor, but put it down to carb tunning and I had no intention of running the carb beyond initial startup so did not pursue at the time.

Ford 302 with Flowtech aluminum heads. 
Fitech EFI
Ford E-Cam

The Fitech EFI seems to be doing it's job in that it fires up the engine, controls idle and A/F mix as expected.

Of note is that the vacuum is low  but rock steady at 10 inches of Hg. Should be above ( below?) 16 in my estimation. This is at an idle of 800 rpm and between 12 to 18 degrees of timing. Timing has a small effect on the vacuum but nothing significant over that range. Total advance is 34 degrees with 12 initial.
Cranking cylinder pressure is 135 psi. Rather low in my estimation for this cam and the expected compression ratio of 9.5/1

Based on vacuum readings and the way the vacuum drops at higher rpm, I thought I had a plugged exhaust. Disconnecting the exhaust at the header pipe made no difference. So cross that off the list, 

Next stop is to pull the timing gear cover and see if the timing is off by a tooth, mostly cause I cant think of any other thing to check. The guy who put it together has done maybe a hundred 302s and he doubts we made a mistake, but you never know. Only one way to check.

I discounted an intake leak in that I sprayed an entire can of brake-clean around the manifold to head and EFI to manifold joints with no discernible effect. Plus I don't think vacuum would drop with rpm if it were intake vacuum leak related.

Open to any idea that anyone might have. Start pulling the engine out tomorrow. If nothing jumps out as the culprit, the engine out of the Challenge car might end up in the Molvo. 

Pete

If you were off by a full tooth on the cam timing, there's a good chance you'd have had piston to valve issues -- did you check clearance?  As mentioned before -- mine with stock fox body CR (9.0:1), Y303 aluminum heads, GT40 intake and shorty headers -- never got higher than 11" vacuum.  Seems unreasonable to me to expect 16" without a MUCH higher static CR.

Cam timing being off should shift the power band around -- but shouldn't keep it from revving freely.  I'd focus on FITech and ignition.

What's the background on the short block?

In reply to MichaelYount :

Built the short block with new parts. Basically a stock 302.  Pistons are 0.020" over.

The RPM drop  was also apparent with the carb that I originaly put on to fire the engine.

Weird about the e-cam not pulling vacuum because I have stuck the vacuum gauge on two other e-cam engines and they are over 16inches  with pretty much stock short blocks. 10 degrees base timing  and 800 rpm.  Also the drop to 5  inches of vacuum or less when reved and held steady  needs explaining, that would not be Fitech.

Actually went out and bought a brand new points ignition system yesterday in hopes that a stone basic technology would help, only to find out the fitech wont work at all with a points system.

You are on the right track in that the entire engine might have to be pulled apart to establish valve clearances and actual compression ratio. Cause when all else fails...

As I recall, with a stock block 91 fox body motor, I had about .110" clearance on the intake side; and .210" on the exhaust.  Exhaust is more critical since the piston chases the valve closed -- float hangs 'em open and a smack can occur if clearance isn't sufficient.  

Pete, I'm operating off memory -- but from 2002 - 2015 or so, when I was active on the Mustang forums (5.0L in mine then) there were COUNTLESS posts from folks disappointed with idle quality and low vacuum, low rpm torque after they installed their E cam.  Not doubting your experience -- just saying it's not a once size fits all.  Still remember this one guy who had something like this in his sig -- "Best mod?  Removing the E cam and putting the stocker back in."  As mentioned before, it really wakes up with more static compression, but it's not very happy under 2500 rpm with the 9.0:1 fox body motors.  Most folks were young = they loved the rough idle and just kept the revs up.  I lasted a few weeks - sold it and got a custom.  One of the best moves I made with the motor/car.

But I'm where I was before -- I can't see a mechanical problem with the engine preventing it from revving.  I think it has to be fuel or spark related, at least based on what you've seen/shared thus far.

If no difference between carb and fitech, I'd be looking hard into every spark component. 

Been awhile since I was in the 5.0 world but if I remember right timing should be around 12 btdc and the e-cam needs to be degreed because if you go dot to dot they can be retarded a few degrees. Though if you have a stock 5.0 cam I'd be putting that back in there, especially for just a nice driver. 

Only other things I can think of are a fuel blockage or low fuel not getting picked up. Firing order with the e-cam is 5.0ho not the usual sbf order.  Or the harmonic balancer spun and its not reading true. 

That's everything I can think of easy wise. 

1-3-7-2-6-5-4-8

With 1-4 passenger side frt to back;  5-8 driver frt to back

Gotta think firing order is ok - if 1-7-3 order is used - they barely wanna run.

How old is the fuel, and has it possibly phase shifted due to ethanol/water?

I'm way late to the party but... yes!!!  That is a damn sexy car. 

NOHOME said:

Going to need to roll the rear fender lips.  I thought it was going to be OK, but the car settled over one inch on the drive and started to rub on both rear tires.  Bit of camber would help, but it gonna be Hella.

Is that with a full tank of gas? Don't be surprised if it settles even more. Everybody is going to have a different opinion on what you should do about it - fender rolling, camber, suspension height, different rims, etc. - but you know this car and not them and you know what is best. 

edit: ok I've updated myself with the last few pages of the thread, lets see, the fact that it idles ok is a great sign. I'm reminded of the time that I thought my carb was sending manifold vacuum to the ignition vacuum advance, but reality was it was a weird California-compliant carb and the vacuum ports were totally different than all other elderbrock carbs. Probably not what's going on here, but just an example of a stupid little thing that can trip you up. Like the timing marks on the engine being in-accurate or something. 

What's fuel pressure like? I always have the worst luck with fuel pumps (on GM cars, especially). IDK. Side note: Mazda and Ford had a partnership (still do for all I know) and my brother had a small mazda pickup that was basically a ford ranger and the thing was a piece of berkeley. You know what, forget I mentioned that. 

After sleeping on this, I believe the key to fixing is going to be finding the cause of low vacuum and I doubt it is entirely on the cam specs.  Low steady vacuum that drops with rpm is THE classic diagnosis of a cam that has skipped a tooth. Going to start there. 

The fuel pressure is 40 psi at idle and 76% duty cycle controlled by the Fitech. Since the Fitech uses vacuum to increase the fuel pressure, having vacuum drop to 5 inches of Hg when reved is not helping the cause.  Going to set the duty cycle to 100% so as to remove that vicious cycle from the equation,

135 psi cranking cylinder pressure is not sitting well with me. Voice in my head says it should be over 150. Can't see a street cam having the overlap to drop cranking pressure that low.

What role are the Flowtech heads playing in this? Alloy headed engines should have compression bumped in order to have any benefits from the alloy thermodynamic  bit, and I suspect that is not the case here. 

That all said, the Fitech is able to handle cams with very low vacuum down into the 5 inches of Hg range and those cams will then go on to produce vacuum as the revs go up. So, even if the E-cam is not the ideal low rpm vacuum producer, I need to find out why the engine is losing vacuum with rpm. The engine is literally backing up with pressure as it gets reved, like there is a cork in the exhaust, even with open shorty headers. 

One other odity that I have not mentioned is that the exhaust on one bank of the engine is running 100F hotter than the other bank. I was putting that down to a constipated exhaust with maybe a failed cat, but as it turned out the exhaust is not clogged ( well it may be, but disconnecting makes no difference to the observed issues) Have not repeated the thermal check with the open headers just cause it is a bit too noisy for the neighbors.

Except for the aggravating bit, this is kind of an interesting puzzle. Bound to have learned something new by the time it is all over.

Pete

EDIT  Fuel is fresh 91 octane.

NOHOME said:

Except for the aggravating bit, this is kind of an interesting puzzle. Bound to have learned something new by the time it is all over.

I feel like that is the perfect (necessary) attitude to have for this hobby.

NOHOME said: 

The fuel pressure is 40 psi at idle and 76% duty cycle controlled by the Fitech. Since the Fitech uses vacuum to increase the fuel pressure, having vacuum drop to 5 inches of Hg when reved is not helping the cause.  Going to set the duty cycle to 100% so as to remove that vicious cycle from the equation,

----

One other odity that I have not mentioned is that the exhaust on one bank of the engine is running 100F hotter than the other bank. I was putting that down to a constipated exhaust with maybe a failed cat, but as it turned out the exhaust is not clogged ( well it may be, but disconnecting makes no difference to the observed issues) Have not repeated the thermal check with the open headers just cause it is a bit too noisy for the neighbors.

So 40psi is what the Fitech asks for? I don't understand how upping the duty cycle on the injectors is going to fix anything if lack of fuel is the issue.. How does the fitech control the FP? Is it just a typical vacumn referenced setup?

Any chance there's something weird with the intake manifold? Got a spare you could try? Just thinking that if the issue was the same w/ fitech or the carb..

I've been following along for some time but have remained on the sidelines because your abilities to resolve any and all issues are second to none so what value would I be able to add?  When you threw the white flag, I did some poking around with the people I know and the following seemed to make sense to them.

If it was a jumped tooth on the cam, it would run very rough at idle if at all so that seems unlikely.

The fact the vacuum goes down as RPM's go up would indicate a collapsing vacuum line as the culprit.

Also, PVC might be a long shot item on the what to look for next list.

My 2 cents for today.

Two vacuum sources on the engine: one mechanical and one Fitech display. The two agree.

The Fitech looks at  what I believe is rpm and uses pulse modulation of the voltage to the fuel pump to control the fuel pressure. This means that at idle the pump receives less power from the fitech and thus provides lower pressure when it is not needed. IF vacuum is one of the inputs to the fuel pump pressure control, then it is going to be working against me and might in fact be what is shutting down the engine when I try to increase and hold higher rpm.

As to running one tooth off? The fitech is pretty amazing in what it seeems to be able to do to keep the engine running. When I tried the points ignition, it did it's best to keep it running but all it could muster was 5" of vacuum and 350 rpm for maybe 30 seconds.  If anything, this ability to keep a less than ideal engine set-up running almost "good" is a curse in disguise; people will spend hour or weeks trying to sort the Fitech tune when it fact it is a real engine issue.

Power brakes and pcv are not an issue or source of the low vacuum.  No EGR valve on the engine.

 Engine gremlins aside, the car is amazing and it drives!! I just want to repeat that fact because it deserves to be said again.

NOHOME said:

135 psi cranking cylinder pressure is not sitting well with me. Voice in my head says it should be over 150. Can't see a street cam having the overlap to drop cranking pressure that low.

But is that before or after a break-in period? I'm reminded of the time I rebuilt my small motorcycle engine with new pistons and everything and after the break-in period, compression was reading 120psi when it should have been 140+. Wide open throttle, no choke, verified with a 2nd gauge. The fine folks at hondatwins.net told me that 120 was not good enough and that I had a problem. Well, I didn't listen to them and I commuted on the bike every day for years (down to a weekly cruise thees days) and it has plenty of power, idles great, and has never given me any problems. Still registers 120psi. I guess what I'm saying is: if this car is for Mrs. NOHOME to cruise around on weekends then you don't need to sweat the potentially, slightly low compression. Especially if all cylinders are reading that same compression. 

Fair enough.  That's all I got.

As I suspected, you have all the bases covered.

Watching with interest.

NOHOME said:One other odity that I have not mentioned is that the exhaust on one bank of the engine is running 100F hotter than the other bank. I was putting that down to a constipated exhaust with maybe a failed cat, but as it turned out the exhaust is not clogged ( well it may be, but disconnecting makes no difference to the observed issues) Have not repeated the thermal check with the open headers just cause it is a bit too noisy for the neighbors.

Any chance of fuel delivery problems on cylinders in the "cooler" bank - if it's not getting fuel then it won't run as hot.

Charley

Did you degree the cam on install to check valve events or just a dot-to-dot?  Having wrestled that timing set on/off more times than I can count - can’t imagine a jumped chain.  

I struggled as well with overly rich mixtures at idle because of the havoc low vacuum was wreaking with fuel pressures.

In reply to CharleyK :

At this point everything is open to being questioned. If there is one thing that I know about new parts, it is that they have never worked at all, so never assume they are going to work.

By the way, with the lights out, it gets pitch dark in my shop and boy do the SS headers ever get a red glow!

Pete

glowing headers = high EGT = either a whole bunch of boost, or really late ignition timing pushing the flame out the exhaust ports, or maybe other reasons

In reply to AngryCorvair :

That's more likely - especially since the engine won't rev - almost like the exhaust valves aren't closing right - back to the cam timing being off.

Well...if nothing else, the engine conundrum is getting me closer to the 100 page thread point! 

If if that is not a milestone what is s?

Pete

In reply to NOHOME :

Is valve lash right?  I've done it wrong before and had the exhaust valves to tight and not fully closing.