Phenolic Intake Manifold Spacer

[andyofcolumbusmerkur]

I hear these cars will run in a sort of limp mode with the VAM disconnected. Will they if the BAP or any other input is disconnected? Nothing happens at all when the knock sensor is disconnected. What about the temp sensor in the VAM? If the computer doesn't get this input will it go off a temp sensor in the intake? Didn't you modify that area some? Maybe something is intermittent and causing hiccups.

[thesameguy]

Nothing about the fuel injection system is modified or hacked in any way, aside of course from the normal LA3-swap things... that is, there is no fuel grade switch, there is no VSS. Everything normally done is done, in stock locations and nothing more. Well, the coolant temp sensor was relocated from the lower intake manifold to the heater core circuit, but that's where Mustangs and Rangers put it so it should be fine - coolant temps are similar in both places (verified).

I believe that nothing can stop LA3 short of a crank signal so I can probably disconnect anything I want. The gotcha here is that the car went from operating perfectly to not operating perfectly one night, sitting still. I don't think it's likely multiple things failed all at once, so right now I am looking for the One Thing that is causing this issue. It wasn't bottom end, or head gasket, or ignition, or intake so now I'm onto the fuel system. Of course, one of the crap parts about living in 2019 is that when you buy stuff - especially electronics, especially reman'd stuff - you just can't trust it. And, really, that's where I am - I fundamentally don't trust the "new" VAM I bought.

[thesameguy]

So...

Put the old VAM back in after cleaning the temp probe with MAF sensor cleaner. The rest of the insides looked good. Connected everything back up, reset idle & TPS, and car instantly runs better. Idle is smooth, exhaust smells good. I didn't drive it so I don't know about sputtering or loss of power, but at least it's not shaking and burning down the cat.

A small but maybe relevant discovery is that the Bosch part number on this VAM ends in 027 which is the VAM for a BMW. The Bosch number for a Ford ends in 030. Cardone says both cars get the same VAM, but another remanufacturer ("Micro Tech Auto") says they are not. Several sites claim interchangeability, but a post for forever ago on this forum says they are not.

Who to believe? IDK. But, maybe the part number difference explains the behavior difference? I'm going to see how the car does tomorrow, then see if O'Reilly can get me an 030 VAM.


Edit: Also, I just noticed but the door on the reman unit is WRECKED. Super floppy on the first cm of travel - it does not snap shut like it should. ROFL.

[thesameguy]

Previous VAM, new BAP, same results. Car generally runs well, but there are some definite flat spots in power delivery. Last night I triple-checked the TPS for response and got perfectly smooth performance between .935v (idle) and 4.69v (wot). It's gotta be the VAM. If I had slightly more energy I would hook up the oscilloscope to it and see what it's doing but ugh... what a pain. I'm gonna try another reman, or maybe see what else I've got in the garage, or maybe just for grins take one off the parts car. I got options.

But I'm going to push my luck and try and smog it as-is. The flat spots are around 3k with small throttle openings... I don't think they will be an issue for smog. If it's gonna fail, it's probably because I wrecked the cat driving around with that crap reman,. Oops.

[John Brennan]

Previous VAM, new BAP, same results. Car generally runs well, but there are some definite flat spots in power delivery. Last night I triple-checked the TPS for response and got perfectly smooth performance between .935v (idle) and 4.69v (wot). It's gotta be the VAM. If I had slightly more energy I would hook up the oscilloscope to it and see what it's doing but ugh... what a pain. I'm gonna try another reman, or maybe see what else I've got in the garage, or maybe just for grins take one off the parts car. I got options.

But I'm going to push my luck and try and smog it as-is. The flat spots are around 3k with small throttle openings... I don't think they will be an issue for smog. If it's gonna fail, it's probably because I wrecked the cat driving around with that crap reman,. Oops.

If they did wreck your cat with that POS, hold them accountable.

What would really be fun is going Megasquirt, getting rid of the VAM, and just having an open dummy in its place.

[thesameguy]

It'd be hard to prove if that thing did wreck the cat, and I'm sure it's on its way out anyway, but I would DEFINITELY raise some hell, especially now that I can leverage the part number and the goofy door. It's a bit irrefutable.

I have been looking at PIMP for a long time, but resisting it since it's not even remotely smog legal. Even with everything I've done to the car, it's still by the book... well, not the turbo, but it's defensible. Still, I'm not truly worried about passing a visual with MS/PIMP, but I'm a little concerned with my ability to dial it in well enough to pass smog.

BUT, I've grown more comfortable with tuning over the past couple years and more frustrated with EEC. I got here with my Saab SPG a couple years ago - MAFs and distributors are impossible to find - and now it's running Saab Trionic 5 from a '99 (MAP, coil on plug, SEFI) and sports a BAR label exempting it. If this particular moment in time (bad VAM, need smog) becomes any more annoying I may be a new PIMP user by the end of the month.

[thesameguy]

Well, the car passed smog! A wee bit tight, but it's been tight for eight years so I'm not stressing on that.



With this configuration there is a tangible dead spot at 3000rpm with a little throttle. If you've dropped the hammer that moment goes by very quickly, but in normal driving it's annoying. Also, if you get caught in that dead spot during a throttle transition it can be scary. As long as you're going from 2000rpm to 4000rpm it's fine, but you basically cannot be at 3000rpm and 10% throttle or you're stuck. Since it *seems* to be airflow dependent, I'm blaming the VAM.

I'll see what O'Reilly's says, but I am seriously considering leaving it as-is and saving for a couple months for a PIMP. I've got two years from today to get it dialed in!

(I *still* don't need another car project right now, but carpe diem!)

[John Brennan]

Well, the car passed smog! A wee bit tight, but it's been tight for eight years so I'm not stressing on that.

https://1drv.ms/u/s!AqwvoBt9ZBp2go8qp3EUN03cyhEdwg

With this configuration there is a tangible dead spot at 3000rpm with a little throttle. If you've dropped the hammer that moment goes by very quickly, but in normal driving it's annoying. Also, if you get caught in that dead spot during a throttle transition it can be scary. As long as you're going from 2000rpm to 4000rpm it's fine, but you basically cannot be at 3000rpm and 10% throttle or you're stuck. Since it *seems* to be airflow dependent, I'm blaming the VAM.

I'll see what O'Reilly's says, but I am seriously considering leaving it as-is and saving for a couple months for a PIMP. I've got two years from today to get it dialed in!

(I *still* don't need another car project right now, but carpe diem!)

If O'Reilly's will replace it, let them do that, so you have a spare part you paid for for sale or trade, and/or if you decide/need to go back to stock for, um, any reason.

[thesameguy]

I am sure they will replace it. My hope at this point was that they'd refund it... since I no longer need it to pass smog, it's $100 in the PIMP kitty. But, I doubt they will. Usually these places have pretty strict policies about returns of electronics. Boo. But, I did this to me.

… and, at some level, I guess I wouldn't be mad about the XR being at 100% before changing anything further. Nothing sucks worse than solving two problems at the same time.

[thesameguy]

Bah.

Old VAM showed symptoms of FUEL CUT FULL STOP this morning on the way into work.

I'm jumping the shark, gonna replace the fuel pump. The car has a Walbro swap, the pump is maybe ten years old but only has 20k or 30k on it. Mild loss of power and FULL loss of power? Fuel pump seems reasonable.

Maybe I will try replacing the FP relay first, just in case.

Weeeeeeeeeeeee.

[andyofcolumbusmerkur]

Did you end up swapping out the computer to see if anything changes? I see your voltmeter but do you have one as a gauge on the dash? Maybe voltage is getting low while diving and making the computer act up.

[thesameguy]

I have not swapped the ECM yet, but I just don't have real reason to suspect it. I will try it this weekend (along with a spare used VAM I have) just to be sure... before spending more money. I do have a voltmeter and charging stays good at all times - and there is no dimming of lights or anything like that. Just a weird hesitation from 3k to 4k with part throttle. Such a weird, specific problem. I wish I had a fuel pressure gauge I could use while driving. The only one I have is a mechanical diagnostic one, and running gasoline into the car seems like a bad idea. I suppose I could tape it to the windshield or something.

I wonder if someone makes an inline fitting for an electrical gauge? I could steal the one out of my SPG for a little while pretty easily.

[thesameguy]

I wonder if someone makes an inline fitting for an electrical gauge? I could steal the one out of my SPG for a little while pretty easily.

Ugh. They do.

https://www.rallysportdirect.com/part/f ... r-5-16-8mm

$50!!

It's barely more expensive to just replace the pump and see what happens. $50 for the adapter, $20 for a second sensor... yep, cheaper just to replace the pump pre-emptively. Boo.

[andyofcolumbusmerkur]

If you lived closer I'd let you try a whole fuel rail and regulator from good running car. And any thing else you think of to eliminate.

[thesameguy]

The injectors (Tomco) and the regulator (Ford) are both just a couple years old, so I am pretty confident in them.

I am trying to figure out a cost effective way to get a fuel pressure gauge on there, but the damn Ford quick connect fittings make for a really annoying roadblock.

It's gonna start raining again so work will probably be on hold for a bit. Maybe by the time things clear up I will have found a fitting or adapter that works!