Sluggish to build RPMS; Part throttle bucking/loss of power...

[ozanracing]

Well here it is again, A spinoff problem of the WOT misfire I was having.
I replaced the maf with a calibrated PMAS, installed a kirban FPR (the holly was letting fuel into the vac. lines) and Fuel pressure gauge W/autometer braided line on the cowel so I can see actual realtime fuel pressure. Changed the plugs, #7 appeared pitted,(the wire was touching the oil dipstick) most were oily/black carbon. Changed the oil, and installed an accumulator in the PCV line. It now catches an ounce or so of oil residue per every few WOT blasts through the gears. Set the fuel pressure to 40psi timing to 17*. I'm going to lean it out, because I know the 30lb injectors are overkill, and are only really needed when spraying.
Replaced the wires with taylor thundervolt (50ohms/ft).
Listened to the injectors, all were firing properly....
And preiviously just replaced the TFI, tested TPS, replaced vac. lines (all), PCV, and cleaned all connectors and grounds etc etc etc...

So now the power is back but the thing surges at idle, and sometimes gets so low it shuts off. If I hold the rpms steady at 1300rpm, then give a real quick tap to 2/3 on the pedal, you can hear the throttle body whooosh open and the air rush in but it takes a moment for the rpms to come up. It hicups then builds gradualy, slow and sluggish (rich). It used to be razor sharp. While driving in 2nd; 2500rpm I hold the gas steady and it bucks and seems to cut out slightly...Very annoying to drive in traffic especially with the hunting idle. (sometimes up to 1700rpm up and down back past the 1000rpm ideal idle to 500-600rpms...

Seems low on power everywhere, but past 3500 things seem to get better, smoother more linear. (02 sensors gone bad??). I need to get my WB02 and tweecer...!!! Driving my crazy not being able to see what's going on!

Thanks for any ideas!!

 

[91 HATCH]

I THINK YOU HAVE A VAC LEAK OR A MIS ADJUSTED TPS

 

[ozanracing]

Vac is good all new hoses/caps. Just adjusted the TPS properly....I think I'm going to drop fuel pressure and get a new IAC motor ($50) the flange that the bolts it to the throttle body is cracked. (possible leak defeating Iac operation??)

*UPDATE*

Noticed moisture/condensation building up on the underside of the oil filler cap.
the coolant also seems low again (maybe a quart or so) but I JUST filled it up the other day. Could this be a leaking HG? I actualy used crappy mr. gasket cheepo ones. I painted them and installed them. I dont' notice any smoke, except Sometimes, very slight whitish smoke, like in the morning on a car with an catilitic converter may smoke white, you know?

The battery is dead (left the fans on) so by tomorrow I should be able to start it and drop a few psi fuel pressure and test things further.

I'd like to do a cyl. ballance test, although I tested spark visually with a timing light connected to each cyl and the light acted the same on all cyls. then I listeded to the injectors with a mechanics stethascope and they all fired the same.
And I will prob. get a compression test-guage so I can see if the cyls are sealing...

I also forgot to mention I just replaced the fuel filtrer and the pump isw a 6 month old 190lph unit....

 

[ozanracing]

Here is what the accumulator installed inbetween the PCV and intake vaccume line has picked up in about an hour's worth or running the motor and a few WOT runs...It appears to have a slight green hue to it, wich would indicate coolant.
It is also of a watery consistancy, and you can see splotches of OIL in it, like if you were to puor a few drops of oil into a cup of water....
So the plot thickens....!

 

[ozanracing]

ttt

 

[ozanracing]

I trimmed the fuel to 37psi, and cleaned the salt & pepper connectors, and it feels good again. FAST. Pulling steady 14"vac. Hardly and surge. Put the clutch in and rev it and it still seems a tad slow/hesitant..Under load 3rd gear 4000rpms or so it falters a little...But the thing is when I let off the gas and put in the clutch the rpms hang right at 2500 for a few seconds..then comes back down to 1000...that's the same symptom it started doing in the first place before I replaced the maf, fpr, tfi, plugs, wires and the list goes on and on...ANY MORE IDEAS>>? THANKS!

 

[ozanracing]

***UPDATE***

it mysteriously stopped depositing oil/water/whatever in the accumulator. Here is a pic, where you can see it's mostly water residue, and only a small ammount of oil.
HOW DOES WATER GET INTO THE PCV/VAC LINE??
You can see in the pic how it's "milky" colored...

There is moisture under the filler cap also. I drove it hard today, and felt roughly 90% of it's normal peat power...I pulled the upper intake off and took some pics. Here is a pic of a "normal" port....Residue in the lower, then clean in the head.

Cylinder number 8, however, Is the only one to look like this:

Why is there all that sludge in there? (especially in the combustion chamber) Fuel injector sticking open and fuel washing back up into the port?? Why/How is this happening??

I pulled the plug in number 8 and here it is:

By comparison here is the #5.

I'm thinking about pulling the heads and doing HG's, but only if it's nessescery. Think THIS is what is causing all my headaches??
Pulling the dipstick the oil looks fine on the tip.
Maybe I'll just change it again to see if it's contamonated.

Is this making me lose hp/stutter/hesitate/BS etc...???
THANKS GUYS!! NEED ANY MORE DETAILS/PICS JUST ASK! HELP!!

 

[BigHairyMonkey]

try changing the o2's if you havent already. They have ALOT of pull on how your car acts part throttle especially if you say your stuttering WITHOUT a pop outa the intake (its running rich not lean). Your o2's prob went kaput and its dumping fuel like crazy. Also check your ECT, IAT sensors. I too sadly am trying to hunt down a loopy problem like yours. Except mine runs lean every once in awhile. it seems to go away when i warm up so i think its either the ECT or IAT, replaced the 02s already. Also got a new IAC and cleaned the TB, etc. Good luck

 

[jrichker]

Do the simple stuff first - like dumping the codes.

Dump the codes and see what the computer says is wrong…Codes may be present in the computer even if the Check Engine light isn’t on.

Here's the link to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great.

See http://www.troublecodes.net/Ford/

IF your car is an 86-88 stang, you'll have to use the test lamp or voltmeter method. There is no functional check engine light on the 86-88's except possibly the Cali Mass Air cars.

Codes have different answers if the engine is running from the answers that it has when the engine isn't running. It helps a lot to know if you had the engine running when you ran the test.

Trouble codes are either 2 digit or 3 digit, there are no cars that use both 2 digit codes and 3 digit codes.

For those who are intimidated by all the wires & connections, see http://www.actron.com/product_detail.php?pid=16153 for what a typical hand scanner looks like. Normal retail price is about $30 or so at AutoZone or Wal-Mart.

Or for a nicer scanner see http://www.midwayautosupply.com/pc-7208-90-equus-digital-ford-code-reader-3145.aspx – It has a 3 digit LCD display so that you don’t have to count flashes or beeps.. Cost is $30.

 

[ozanracing]

I'm going to try do a compression and leakdown tests this weekend, if I can get around to it. Have a good memorial day!
Will post results when finished...

 

[ryan218]

Do the simple stuff first - like dumping the codes.

Dump the codes and see what the computer says is wrong…Codes may be present in the computer even if the Check Engine light isn’t on.

Here's the link to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great.

See http://www.troublecodes.net/Ford/

IF your car is an 86-88 stang, you'll have to use the test lamp or voltmeter method. There is no functional check engine light on the 86-88's except possibly the Cali Mass Air cars.

Codes have different answers if the engine is running from the answers that it has when the engine isn't running. It helps a lot to know if you had the engine running when you ran the test.

Trouble codes are either 2 digit or 3 digit, there are no cars that use both 2 digit codes and 3 digit codes.

For those who are intimidated by all the wires & connections, see http://www.actron.com/product_detail.php?pid=16153 for what a typical hand scanner looks like. Normal retail price is about $30 or so at AutoZone or Wal-Mart.

Or for a nicer scanner see http://www.midwayautosupply.com/pc-7208-90-equus-digital-ford-code-reader-3145.aspx – It has a 3 digit LCD display so that you don’t have to count flashes or beeps.. Cost is $30.

i dont see how you will get codes from a voltage meter? or is that just to make sure power is getting to the connection? im gonna try it again sunday...

 

[795.0pacecar]

Jesus tap dancing Christ ryan. You don't use a digital volt meter, you either use an analog volt meter or a test light to get codes, then you count sweeps or blinks to get the code.

Or you can get a code reader from autozone for 25 bucks.

 

[iwashmycar]

i had some hesitation problems not too long ago...O2's fixed it right up!

 

[ryan218]

Jesus tap dancing Christ ryan. You don't use a digital volt meter, you either use an analog volt meter or a test light to get codes, then you count sweeps or blinks to get the code.

Or you can get a code reader from autozone for 25 bucks.

damn man where have you been... i tried a code reader...it wont even light up...ask justin..works in his 93 my dads 86 but not mine

 

[LtDavis]

I also had a hesitation/bucking problem and new O2 sensors fixed everything.

 

[795.0pacecar]

damn man where have you been... i tried a code reader...it wont even light up...ask justin..works in his 93 my dads 86 but not mine

I haven't had time to get on lately, I have a new job that keeps me busy, and my little sister passed away on the 14th so theres been a lot goin on around here lately. So I'm not usually in the mood to give advice.

 

[ozanracing]

So If the compression test checks out fine (by the way what psi am I looking for? 150? 10%variance between cyls?) What else could be going on? That would mean the head gaskets arn't leaking, so is it that 1 injector? I can try putting my stock ones back on.....I just dont get it why that intake port/combustion chamber looks so oily/fuel deposits/grimy!

 

[ozanracing]

Thanks for the insight. There is no egr however. I fabbed a block-off plate for it,
but did not delete it's function in the ECM. So the injector is good then>?
This is a gasket problem then. I'll fess up. I painted the head gaskets with some silver paint. I bet that's what is causing this. But detonation?? the plugs are 1 step colder than stock. (autolite 3924's). I'm going to try the comp test, and prob. order new head gaskets and intake gaskets. The fel-pro 1262R intake gaskets I use come without felpro's "print-o-seal" so it's just a flat gasket, no seals around the ports. Should I be sealing the edges/entire ports with RTV? Or just install them dry? I might get bored and just rip the heads off and take a look today/tomorrow....Will snap pics for you guys.....THANKS EVERYONE!!

 

[ozanracing]

ON the left is the plug out of the #8 cyl. on the right is the #7 plug. They all look like the #7 plug. This set of plugs has like, 40 miles on them...I hope the comp/leakdown test can point me in the right direction...

***UPDATE***
I started to do a compression test. I did NOT warm the motor up first, since the upper intake is off. There is something else going on, I don't think it's a head gasket. I cranked the motor over and the #8 cyl blew 180PSI the other 4 I tried #4,5,6 and 7, all blew 170-180PSI.

I took more pics. Look at this first one closly. See where the intake port meats the cylinder head intake port, at the gasket? See how it looks brand new?? Well they ALL look like this EXCEPT #8.

Now look at the #8 cyl. See how in the actual head there's all that build up?? WHAT IS CAUSING THIS?? My theory was a messed up injector, and that may explain why it would hand at 2500rpm's for a few seconds when the throttle is released before it settles back into idle.

The #8 plug has those deposits on it, and looks like high-speed glasing/ Detonation?? WHY?? I'm going to try swapping over injectors to my known-to-work-good stock ones. OTHER IDEAS???

 

[ozanracing]

ttt