Strange engine activity?

Topic: Strange engine activity? (Read 3228 times) previous topic - next topic

Strange engine activity?

Reply #30 – October 27, 2009, 10:38:00 PM

Have you run codes again to see if it has any new ones???

The '93 Grand Marquis gave me a fit last spring with a on/off miss... Turned out to be a bad spark plug and they weren't even 6mo old... Can't say it hesitated(does that when the MAF meter gets dirty), but sometimes it ran so poorly, you'd almost think it was going to quit...

Strange engine activity?

Reply #31 – October 27, 2009, 10:47:46 PM

It shouldn't cause a problem if its disconnected, unless it was already gummed up when disconnected. Hopefully the vac is capped off on the engine side.

Strange engine activity?

Reply #32 – October 27, 2009, 11:58:03 PM

I tried running codes again the other day and I got 22 again. Even though I just replaced it. As for the vacuum lines, no the one leading EGR plate is not blocked off. The vacuum diagram is missing from my car, are there any other lines I might have missed that go to the EGR valve. Again not my doing my father was the one that did it even though I told him to hook it up. But he did mention when the EGR valve was hooked up that it ran worse? Possibly clogged you think?

Peace,
Dan W.

Strange engine activity?

Reply #33 – October 28, 2009, 12:24:32 AM

Quote from: Roehm;294800

As per recommendation I checked all the vacuum lines and they look fine. ?

\

look?

how about test them. unplug / cap one end and put suction on the other end one vac line at a time.

check fuel pres with the guage taped to the windshield.

check TPS with an buttstuffog meter

other than that,, replace the injector screens (most common hesitation cause imho)

Strange engine activity?

Reply #34 – October 28, 2009, 04:35:56 AM

I saw turbocoupe50 say that a bad vaccum line will not throw a code on the MAP sensor. I would start looking at wires. Especially where we know the car had the motor swapped out. The wires could have been pulled hard or pinched and damaged.

Unless the new map sensor is bad, I would bet on wiring. Try throwing the old one back in after you check out the wires. Your TPS sensor does now have to be adjusted. As long as it is between .76 and 1.1 volts at idle, it is fine. The computer automatically resets the value to match your highest. As long as it hits above 3.5V or so and does not have any dead spots with throttle change, it is fine.

This site here http://www.veryuseful.com/mustang/tech/engine/#Diagrams
Has diagrams that you can use for a guideline for your major vaccum lines. Your car may have more or less lines then the diagram. But most are the same.

If you think you may have a stuck injector, you can initiate a cylinder balance test while pulling codes by waiting until it starts giving you codes, you floor it all the way and then let off. It will give you codes if any cylinder fails the balance test. From my under standing, it turns the fuel injectors off and on after raising the idle to ensure the motor will not die. If you have a stuck/bad injector, it should rear its ugly head there.

Check the wires that go to and from the map sensor really good, and let us know if you find anything weird,broken, or damaged.

Strange engine activity?

Reply #35 – October 28, 2009, 10:10:47 AM

Is the MAP a continual fault(first test in KOEO), or is it in memory??? If it's in memory clear it and see if it returns(vac could be a issue here)... If its a continual fault, you may well have a wiring problem...

Strange engine activity?

Reply #36 – October 28, 2009, 12:14:28 PM

The code 22 actually showed up in KOEO and CM. I'll go double check the wiring the best I can here in a bit.

Peace,
Dan W.

Strange engine activity?

Reply #37 – October 28, 2009, 01:13:44 PM

Just got back inside. All the wires going to the MAP sensor look fine, as do all the other wires I could see under the hood. Tried hooking up the EGR valve and it runs pretty bad with the vacuum hooked up. But with it unhooked it runs a lot better. Unplugged the TPS and the motor revs so that seems like it works..but haven't checked if it is within parameters. Now I remember posting this before but I'll do it again. When I unplug the IAC, nothing happens. Not sure if its suppose to do that or not.

Peace,
Dan W.

Strange engine activity?

Reply #38 – October 28, 2009, 03:13:25 PM

If it runs py with the EGR attached, the EGR diaphram is probably ruptured.

I had the exact same problems your describing when I had really old gas in the tank. Try fresh gas and check the fuel pressure. Perhaps the FP is getting ready to go?

Strange engine activity?

Reply #39 – October 28, 2009, 04:06:06 PM

There was old gas in it but we got rid of it and put fresh in there. Its been running on fresh gas for quite a while now. I'll have to check the fuel pressure but I don't think the pump is the problem.

For some reason I feel I might have been describing my problem incorrectly. So I will retype it to make sure I didn't confuse anyone along the way.

On my way home just a little bit ago. I took off from a light keeping a level amount of pressure on the gas. Not too much as I am a slow driving of sorts and baby my vehicles. When it would randomly act like it either wasn't getting enough gas or air, spitting and spuddering and having no power. So I have to push harder on the gas until it stops and begins running properly. Then I can reduce the amount of pressure back to what I usually drive at. Again this doesn't happen all the time, just when it feels like. When we advanced the timing the most of the problem went away, but it would lightly act up from time to time. There is still the miss with or without the timing advanced its just less noticable when you advance it.

Hopefully that should straighten things out a bit. Sometimes I don't check over what I post and just wanted to clear up and confusion if it exists.

Peace,
Dan W.

Strange engine activity?

Reply #40 – October 29, 2009, 01:25:51 AM

i get it dan,, first and second time

just trying to get you to eliminate a lot of parts quckly.

add to my list,,,,,,,,,,,,,,,,,,,,,,,

at night, spray plug wires with spray bottle of water, coil area to.
look for sparks / archs jumping.

partial throttle typically points to a tps problem. one indicator would be if you "think" the problem happens when the gas pedal is in approx the same location. this consistency would point to as defined,,,"throttle position" or the sensing device

after that, i would pop the dizzy, spray down deep into the stator to clean that part off. there is a magnet in there that could be catching debris.

measure fuel pres
measure tps
plug far end of vac lines and suck on the other end and see if they hold suction
spray carb cleaner along vac lines and intake mounting areas including throttle body mounting and listen to engine rpm changes.

just for grins
rotate your crank to zero deg on the pointer.
now gently rotate the crank ccw and read what deg the pointer is pointing to on the harmonic balancer. this will tell you how much slop is in the timing chain. I might be backward on my directions but either way you will see what i mean.

Strange engine activity?

Reply #41 – October 29, 2009, 07:29:21 PM

Sorry, I guess I repeated someone else's post. Jcassitys timing chain slack test is a good one to try. I had an engine with a really stretched chain. When I tried to time it, the spark location would jump around unpredictably (with the spout disconnected). When I tore it down it had about an inch deflection on the timing chain. The engine had a part throttle miss like yours, it also would have an occasional idle miss and hard starting. It was a pretty tired engine and may have had other problems.

Strange engine activity?

Reply #42 – November 02, 2009, 01:13:04 PM

Thanks for the advice guys. I'll try some of that stuff out. I just moved to Tennessee and I'm getting settled in.

Peace,
Dan W.