duplicate post---need lotsa help PUHLEEEZ!!!!

[ssnnooppyy]

Dropped some cash at the mech, and then he says "uh, I don't know". Fuel pump, okay. Plugs, wires, rotor, cap, all okay. Starter, okay. Alternator, okay. Hey, turns out my radiator is even okay.... Didn't even ask for that to be checked... So the problem persists. Vacuum??? Not sure. No codes. Car stumbles off the line, and idles odd. It hesitates all through the rpms, and bogs down under wot. EGR??? BPT??? I did the "easy diagnosis" of the egr, by pushing on the bottom of it, and nothing changed. It didn't move, and the idle stayed the same. I cleaned the living crap outta the intake and throttle body. All injectors are new. HOW CAN I CHECK THE VACUUM?!?!?!? Can I somehow use compressed air? Maybe blow it into a vacuum hose and listen for leaks? Aw geez.... I gotta get her running right... nothing is right in the world when she runs poorly. Hey, and one more oddity, the brakes are kinda weak. (new pads all around,a nd new brembo cross drileld and slotted rotors. Bled brake system, no air) I have heard that the brakes will go if the vacuum is weak.... just repeating what I've heard. I pulled the vacuum hose off the master cylinder after the car was off, and it made a sucking sound (no jokes!). help. car dying.... owner to follow......

[DAEDALUS]

Does the idle change when you step on the brakes in neutral?

[ssnnooppyy]

huh.... i don't know. I shall check that in the a.m.! Funny. Never thought to do that. Good idea though! BTW--- what will that prove or disprove???

[1991240xs]

fuel filter?..that was my problem with those symptoms

[ssnnooppyy]

Nope. I put that on first thing. It is a 300zx type. No lack of fuel to the injectors. And the injectors flow A-OK. The list of new stuff includes new injectors and o-rings, belts, a few hoses, cap, rotor, plugs, wires, filters, and a huge dose of sea foam. (huge=one bottle :-P ) I don't think there is water in the fuel, it had a dose of heet put in after I purchased it. I have been through everything except the one thing that is causing the problem, ya know? The old saying... it's always in the last place you look... DUH! Why would you keep looking????

[Toahk]

ask them to check the MAFS

[ssnnooppyy]

Is there a way I can check it out myself? I am done with throwing money for "diagnostic time" into the old 240. The mechanic I took her to is a trusted one, many friends and family have taken their rides, but to just throw money out the window in "hope".. can't do it. I don't own an FSM... I figure the instructions may be in there. Is there a way to do it myself????

[slw240sx]

could a broken wire harness ona emisions systems part result in a non working part ,thus causing a vacum problem, thus leading to the car only running on 3cylinders??? and i think only #3 is having problemns firing ..

[DAEDALUS]

A changing idle when you hit the brakes indicates a vacuum leak in the brake booster. In the engine, you can spray carb cleaner around the intake and see if that changes the idle too...it'll mean you have a leak there. The MAF you can check 2 ways...resistance when the car's off, or voltage when the car's running. I do not know what numbers you should get, but I would hope they're in the FSM. Probably 1-5V when running, depending on throttle position. Or you can compare it to someone else's car. I have a problem with you paying a mechanic to check the things you want checked. That's just manual labor, and does not warrant a large sum. Mechanics supposedly charge a lot because of their expertise. Shouldn't you just say, "The car's not right" and have him figure it out? That's his job!

[ssnnooppyy]

Ah. I checked the old brake-pedal-in-neutral, and no change. I did notice this little thing today... It was cool this morning, so I figured, why not try a few things. I floored her. She ran like the old days!!!! Then, as the engine got warmer, she ran like the current days . So I let her sit once I got to work, and tried it again. It was warmer outside, but she ran alot better at startup than after warming up. I know it's not the intake air temp sensor... it's replaced with a resistor. I agree with spening money at the mechanics. I figured he could look at some things I may have missed, but turns out mechanics are a little like doctors... "here, try this!"... I am now inclined to think that my brake issue is seperate, and that the running issue is somehow temp related. I know of the coolant temp sensor, but what else is there that would be temp related or temp controlled? I really appreciate all the input and all the help. I double checked all the plugs and wires and cap etc. and it's all right as rain. I feel as though I am getting closer.....

[WorkinDriver]

Jon is there spark on the #3 cyl ? you can check with a cheep timing light, if there is...Is there fuel ? check the presure, you can get a cheep pressure checker from Harbor Fright .... I got an entire tune up kit for 34 bucks. Vac/ Fuel pres checker, remote starter switch, timing light, and a bunch more accessories.

[WorkinDriver]

Snoop ...Sounds like your on the right trail to me too... I had a similar problem, it turned out to be a faulty temp sensor... The brake prob I also had but it was temp related turned out to be the 1 " Booster Line was cracked on the bottom of the hose, so I couldnt see it, But the hose was soft when it was hot so it only did it when warm, Weird HuH !!!

[stanzz]

Well, when you push the disk up on the bottom of the EGR, your car should not run good, in fact mine stalls....try a new EGR valve, cost? I don't know...

[ssnnooppyy]

Nope. No change in the idle when the egr is pushed on. It doesn't move, not evena little bit, so is that shot??? Is that the answer to my nightmares??? I will check my brake vacuum hose monce more.... hopefully I missed a spot!!!!