View Full Version : Is my cam stock? LOTS of crazy ??? & bad car symptoms. And how it was rebuilt (long)

08-09-2007, 01:54 AM
When I bought my 2nd SC, there was a good amount already done to it (air bags in the rear, a rusted out flowmaster exhaust, lowered 1-1/2" (some baby blue springs I dunno what they are?) 3.55 gears, rtv on the tranny, engine bored .030 over, 10% (I think) OD pulley, I think underdrive pulleys (they look stock but were all bigger then my 89 SC - even the main engine one) and a "super chip", which I took right out). The car is a 1991 and has ~70k (original) on it. There was an engine knock, so my dad, grandfather, and I rebuilt the engine. We took WAY too long (over 2 years) to do this, but my grandfather was VERY thorough in the process (practically plasti-guaged everything). Upon taking the engine out and everything apart, I found a piece (side skirt) of a piston in the oil pan (YAY!). :rolleyes: But, you could see the hone marks still in the cylinder walls.

I then found out the problem was with the bearings on the crankshaft. There were lower bearings put on the bottom AND top. The lower bearings had no hole in them to allow the oil to flow through the rods. I took the crank, and rods to a machine shop to make sure they were not stretched or cracked, etc. The guy before me (not sure why) also had the IAC totally blocked with a cardboard "gasket" (but the IAC was plugged in). I noticed on the camshaft there were NO marks whatsoever. Do the stock ford cams at least have a "Ford" stamp on them?

After I got the engine together, I put mustang v6 headers on it, no cats or resonator, and just took off the back mufflers, trying to do some type of exhaust (any suggestions?). Even the way it is, I still get a rattle in the exhaust. Can this be from the heat shield? Would it be a bad idea to take the whole thing off?

Anyways, the car threw "running lean" codes on the left and right bank after doing the dynamic run test. I replaced the fuel filter and checked the fuel pressure at the rails and that was fine. Replaced O2 sensors (Bosch) as well. I also replaced the IAC with a new one from Ford. I have 2 stock MAFS (they are clean and makes no difference if I change them). New autolite double platinums, new Ford spark plug wires.

I know the SC belt is very old and cracked. I want to replace that (I'm sure thats not the cause of the problems though), but I am not sure if autozone sells them, and what the size is (even if I could get a slightly smaller belt due to the smaller OD pulley - the less slippage the better). Any part or belt #'s here would be helpful...

How can you tell if the fuel injectors are properly seated? Also, how do you test the intercooler to see if it leaks? I always hear people say "you might have a VAC leak", but I can't find one, and that is the only thing I didn't test.

The car seems the have poor acceleration, along with stuttering at low rpm's (even at half gas). IF there is an aftermarket cam in the car, does that require a tune? I have like 4 tps sensors, but can that be creating these problems? I had a friend tweak it so it read the correct voltage so the computer can read it.

Lastly, IF THIS WAS YOUR CAR, WHAT WOULD YOU DO?!?!? :confused: (and don't say scrap it! lol) :eek: All I know is my 89 basically stock SC ran perfectly with no problems, and that had over 200k on it! ARRGH I could just scream!

Anyone in the YORK, PA area who would have time to take a look at it, I am a 26 year old veteran (82nd Airborne) with 2 kids (1+ year and 1+ month boys - ugh!). I may not be by any means wealthy, but I can give you some $ for your time... Maybe nothing like $60/hr, but would gladly try to make it worth your time... my e-mail is [email protected] if you have any other questions. Thanks to all of you who have read all of this! I know I posted a few threads before, but I gave ALL the imformation I have and can think of.
Mark Gleeson

08-09-2007, 09:20 AM
I'd say vacuum leaks as well maybe even from an injector that didnt seat did you coat the o rings with oil before puttin them in? if not you could have torn one which would create a massive vaccum leak ...BTW if you wait til the evening more people are usually on here you can get a faster response check vacuum at idle cheap autopart store gauge will work

Tim Groth
08-09-2007, 10:20 AM
Anytime I've had any sort of problems with sluggish acceleration its had to do with a bad plug or a plug wire that's not seated properly. Sounds WAYYYY too easy of a fix but I would check there first.

Also what is your vac at idel? Should be around 18-20...if its showing anything less than that its very safe to say you have a leak, at which point I usually just reseal all the connects for the piece of mind.

Also a Vac leak would probably throw the lean codes for it has to compensate fuel for lost boost.

Good luck on your hunt.


08-09-2007, 01:21 PM
Well if it is a vac leak I am not sure where it is! lol. I can't remember what that vac is at idle, I will have to check. I did just replace all the spark plugs like 3k ago with double platinum autolites, and I did really check all the wires (someone told me that before). You say use a cheap autopart gauge to check vacuum at idle - what is the best way to do this/where should I tap in? and no I didn't coat my o-rings with oil! lol DAMMIT! I guess the best way to find out is to tear everything apart down to the injectors... I guess it will be worth it though if that's whats wrong! If my memory serves me right, I do remember smelling gas under the hood when I popped it before (its been a while I drove/worked on it)

08-09-2007, 01:58 PM
is the name of the game with a SC. My power loss and stuttering were caused by the bad DIS module. On the IC tubes what kind of gaskets are you using? Leaks are usually on the large nut or lower tube. Congrats on the rebuild! I'm prepping for one myself. I may need your advice.

08-09-2007, 03:43 PM
Regarding the exhaust rattle: If you still have catalytic converters, the heat shields on those may be rattling. It's an easy fix, however. Just buy the largest hose clamp you can find (or daisy-chain two together) and wrap it around the cat. Tighten it down and it should eliminate the rattle. Of course, it could come from another source or even the material within the cats, but I don't know. Try getting under the car and bonking the exhaust lightly with a mallet and see if you can replicate the noise.

As for the lean-ness, that may possibly be caused by the computer re-learning how to run with the IAC functional. I don't know why the previous owner blocked off the IAC, but I would guess that he was having trouble getting it to run right after the cam install.

Also, the ECT (coolant) sensor for the EEC has a lot of control over the fuel/air mixture. You could replace that, or at least test its resistance at temperature. Unfortunately, I don't have a temperature vs. resistance chart in front of me. Sometimes the Haynes manuals give info like that. It's almost certainly in the Ford shop manual.

08-09-2007, 05:46 PM
eli66048: My dad made a device that spread the copper RTV in a perfect "gasket" and we did that on all the tubes, and I think it worked great! I also have teflon gaskets I am going to install when I swap out the SC (I have my 89 SC on it, but I need to put my 91 back on with the 10% OD pulley on, and will check the injectors while I am at it). when you talk about the large nut, do you mean the nut/bolt on the left of the top (where it says 3.8)?

S_Mazza: I don't have any cats - it is just mustang v6 headers and straight pipes down to a Y then the "S" pipe, and right now, no mufflers (there is nothing after the end of the "s" pipe, which I did about a week ago - this does not affect my problem I am having I dont think). I have had the car for 4 or so years, and the computer has done the re-learn process ALOT of times, so I don't think that is an issue, because after it being reset totally (sometimes from the battery going dead), after it re-learns, it still gets the codes (others probably too). I actually have 2 ECT sensors (it screws in the intake manifold, right?). My grandpa checked the resistance even for the old one and they are supposedly both ok...

08-10-2007, 11:39 AM
Hmm, well, I don't know exactly what your problem might be then. I would say that, if your cam is aftermarket, it could probably create a lean code. Here is one more electronics question: Is the MAF housing on your car stock? Or did the previous owner maybe cut out the center post? That might screw up the MAF readings.

08-10-2007, 06:35 PM
MAF is stock, I actually have 3 MAF's (a stock one from my 89, a C&L that was on it when I got it, and a MAF that I got with my cold air intake wich is stock from another SC). And I am not sure about the cam wether it is stock or not... do ford cams have some marking or # on them? because there is no # or marking at all on the cam that is in the car...

08-10-2007, 08:09 PM
One BIG problem I see..... if you got a cam and a few other upgrades there, a chip and tune needs to be done to compensate for those changes.

What colour where the injectors?

08-11-2007, 12:42 PM
injectors are red. I actually have 2 sets of injectors (ones from my 89 as well). And are C&L MAFS really junk? I heard alot of people say they are, so I took mine off. And I am not sure where to get a tune done aroud here... That's a big problem for me - I don't know if the cam is stock or not... :eek:

08-11-2007, 02:05 PM
I think people are saying the C&L's are junk because they don't understand whats happening. The ONLY thing a C&L will compensate for is a different injector size if you have the right sample tube. These folks are sitting there adding huge injectors, massive over drive's on the blower, big cam, and various other items and expecting the C&L to adjust for that to.... end result crappy running motor.

Plain and simple... the C&L can ONLY adjust for a larger injector NOTHING ELSE!!!!

The C&L will be okay if you go up to a set of 42lb injectors, but as Dave Dalke referred to in a post in the members section, after that your taking chances because you can only "fool" the computer so much without actually using a chip to keep everything in line. The fooling that happens affects the entire range from just above idle to WOT.

10-21-2007, 04:11 PM
ok here are a few updates (and pictures):

First of all, I replaced my TB - the IAC is new from Ford, and I put on a TPS (closest to having a the characters of a new one - I have 5). The tb I put on is stock, but I don't think the stop screw or the screw with the allen square (I don't know what it is for but it goes in where the IAC is) haven't been messed with. With the car on and at idle the tps reads .95v (that is fine, right?).

Two other things...
I was told the coolant temp sensor can create the car to run lean/rich (especially if there is a bubble in the cooling system and it is not reading the liquid, but air). I THINK there is 2 temp sensors - I am attaching 2 pics - they are of the sensors (the one with the GREEN circle around it I replaced and know is fine - the YELLOW one I am unsure of)



10-21-2007, 04:40 PM
The yellow circled sensor feeds the temp gauge, and nothing else. The green one is for the EEC to measure ECT's.

The TPS voltage your getting is good for idle.

10-21-2007, 05:13 PM
ok is this "correct" for boost pressure at idle? Also since I put the new TB on, it is now going up to like 1700 rpm for a few minutes before it comes down to the normal idle. I just reset the computer, so it may be trying to relearn... But it is missing at the low end so bad it barley accellerates...


10-21-2007, 05:40 PM
Around 20 inches at idle is good

10-21-2007, 05:42 PM
so with a boost leak would you have more or less?

Also, if your SC belt is tore up, would that make your car miss at the low end?

10-21-2007, 06:48 PM
If you had a vacuum leak, then yes your vacuum gauge would be less. On the other hand if you had a boost leak, you'd only see that when boost is happening. There is a good article in the member's faq section that explains how to pressurize your system and test for leaks.

I don't think a bad belt would cause a miss. You'd just get less boost.

Just to add, did you check fuel pressure at the rail? If you didn't hook up the fuel pressure regulator to the right vacuum source, you could be running the car lean. Technically speaking, you need about 38psi at the rail I believe when you turn the key on engine off and on idle. In our cars, that rail pressure should go up when you go into boost pound for pound, so if you hit 5 psi, then you should be seeing about 43psi at the rail.

10-21-2007, 07:33 PM
I did check fuel pressure at the rail, everything was fine - also ran the dynamic run test, the computer said it was running lean on both banks (which is why I checked the pressure at the rail). if you mean this for the testing for leaks I know what you mean:


Meh - I am thinking it is either a cam/crank sensor, or worse yet, the actual ECU or computer... I know when I got the car it had a "superchip" in it (wich I immediatly removed). I also tried to put in my 89 SC computer, and that didn't seem to make it run at all... BAH!


10-22-2007, 11:15 AM
Was it over-revving at startup before the TB install, or only after? If it was only after, it is possible that the air bypass is set incorrectly.

10-23-2007, 11:02 PM
only after it seems after I just put this other (stock) one on. What do you mean the air bypass? the little screw that fits an allen wrench by the IAC? I messed with that to get it back to normal, and seems to idle fine, but still the extreme missing and stuttering at the low end

10-24-2007, 08:51 AM
Have you checked the firing order and the plugs?..Im figuring they are new but they could have been damaged going in. A boost leak wont cause that issue.

Also..I had my superchip with no issues as well as a C&L...What MAF is in there now?

10-24-2007, 11:40 AM
Ok, on the aftermarket throttle bodies, there are generally 2 methods of adjusting idle RPM. What you want to do is to adjust the throttle stop screw (the one that physically stops the throttle blade) so that a little air is getting past and your TPS reads about 0.95 volts. (If that proves impossible, you can sometimes adjust the position of the TPS sensor, but let's leave that out until later.) Once you have the throttle stop screw and TPS set correctly, you need to UNPLUG the IAC with the car off. Then try to start it. The car should be able to hold an idle of about 600 rpm (if you do in fact have an aftermarket cam, this may need to be higher - maybe 750 or 800 rpm). This idle, with the IAC not helping, is called the minimum or base idle. It's ok to help the car find the idle at first by giving it a little gas, but once it stabilizes, it should be able to hold it on its own without stumbling much. Now, if the car can't hold an idle with the IAC unplugged, then you adjust the little allen-head screw on the throttle body. That is called the air bypass screw and it acts as a valve to let a certain amount of air bypass the throttle blade. By the way, shut the car off before each adjustment and restart it to see the effect. If you adjust the screws with the car running, the computer may fight against you and you won't get a precise adjustment.

Ok, now if you do all those steps in order and you still have issues, then you should look somewhere else.

10-25-2007, 03:59 PM
if you guys did everything by the book i think the firing order is wrong in the shop manual.

Scott Long
10-25-2007, 04:26 PM
When you rebuilt the engine and put it back together, are you 100% sure you aligned the cam sensor shaft correctly? The sensor piece on top only reads from the shaft, so if the shaft isn't aligned right the timing will be way off.

Also check the plugs and wires. the top row of the coil pack is 1-2-3 and the bottom row is 4-6-5.

10-26-2007, 10:44 AM
I was thinking that if the cam sensor would be off, that it wouldn't start most of the time? My car starts every time I turn the key... The plugs/wires are both new, and they are going in the right order. I have been questioning the cam sensor, but people say its only for starting the car. I remember my grandpa adjusted it with a voltmeter somehow - is it possible it could be 180 degrees off though? When you buy a new one, do they come with the stupid plastic piece to install it? I heard of different ways to install them (matchbook, voltmeter, etc.) But I figure if I install one, I should just do it right...

11-06-2007, 07:59 PM
bump... any ideas guys? Anyone here in the York, PA area? If so, I wouldn't mind giving someone some money for their time to come out and take a quick look at things! This is my only car, and I get my license back in the next few months, and I hope I will be able to have a driveable car lol

11-07-2007, 03:33 AM
When you rebuilt the engine and put it back together, are you 100% sure you aligned the cam sensor shaft correctly? The sensor piece on top only reads from the shaft, so if the shaft isn't aligned right the timing will be way off.

Also check the plugs and wires. the top row of the coil pack is 1-2-3 and the bottom row is 4-6-5.

Maybe this is my problem???? can the cam ~~~ sensor shaft make the car actualy be Out of time??? i thought it didnt do that much?? everytime my car is warmed up it acts like its out of time when you start it.. cranks very hard... has no low-end t ourque anymore...... Sorry to hijack.