my 94 q45 shakes ???

[jose310]

When i turn on my car the check engine light goes on and it starts shaking, and when stoped at a stop ..the car shaes also and sometimes in take off,??? i have done the tune up..all spark plugs have been changed and the air filter and oil filter, oil flushed,?? anybody can help??

[texasoil]

you will have to pull the error codes from the engine computer (ECU) without CONSULT, you have to physically unbolt the ecu and turn a screw back/forth to trigger the error code readout. It is in the factory service manual (which can be found on-line inNICO) without those error codes, we are all guessing in the dark.

[maxnix]

i have done the tune up..all spark plugs have been changed and the air filter and oil filter, oil flushed,??

Fuel filter, MAF connector, BG44K?

So much to know and so little maintenance history revealed.

Define "tuneup", please.
Modified by maxnix at 8:18 AM 11/9/2007

[jose310]

well, wat i did was changed the spark plugs, change oil, oil filter, air filter, had a radiator flush and a new alternator. i was putting unleaded gas for a good while.,. but now i have been putting prenium, you think the fuel lines might be dirty or clogged up??

[Rex]

was putting unleaded gas for a good while.,. but now i have been putting prenium, you think the fuel lines might be dirty or clogged up??

That's bad.How long did you run the improper fuel?How long have you (now) been running the correct fuel?

What type of plugs did you use?Are you sure all the coil packs were completely re-installed?

[jose310]

well i have 5 months witrh it and since then i have been putiing unleaded gas...but now for like 3 weeks just prenium..and about the coils i havent checked them...how do you check um?? to see if there good or not...

[Q45denver]

http://q45.org/roughidle.html

[Haitian_King]

My Q used to shake like it had Parkinson's. Turned out it was the #8 injector (really easy to replace). I bought some injectors from cccpman and replaced it. The other day, I had tot turn my radio off to make sure my car was still on. No vibration anymore. I couldn't believe it. Soooo smooth.

I would recommend going to a shop, paying the $100 for a full diagnostic and go from there. That's what I did.

The shop diagnosed the problem, and then wanted to charge me $313 for 1 injector. I paid $6.25 for a used known-good injector and paid $45 to have it installed. Car runs like a dream.

And Wes says that a used Q45 injector is way better than a brand new aftermarket injector unless it's from Deatsch.

[Haitian_King]

NIET! NEIN! NON! NO!

However you say it, the answer is still the same. Nothing but Premium in Q's. Newer cars can handle the cheap stuff. But you have a high end luxury import that was designed for people who could afford the good stuff. If Premium gas prices are too much for you right now, then the Q isn't for you. I'm lucky, premium is like $2.69 a gallon here. It'll cost you way more in the long run by not using Premium just to save cash.

Plus, premium burns slower and better.

[Jesda]

Man, Q45.org hasnt been updated in years. I really need to... Zzzzzz.....

[jose310]

gas prices are 3.29 for prenium over here at chevron, but i can afford it and have been putting it since ..and also that Lucas fuel injector cleaner. seems to work for 30k but then just wears of...about the diagnostic, a buddy of mine was trying to run the computer but he coudlnt get anything, i was thinking it was because my diagnostic screen dont work on my dash, so it dont trow any codes.

NIET! NEIN! NON! NO!

However you say it, the answer is still the same. Nothing but Premium in Q's. Newer cars can handle the cheap stuff. But you have a high end luxury import that was designed for people who could afford the good stuff. If Premium gas prices are too much for you right now, then the Q isn't for you. I'm lucky, premium is like $2.69 a gallon here. It'll cost you way more in the long run by not using Premium just to save cash.

Plus, premium burns slower and better.

i have been putting pre

NIET! NEIN! NON! NO!

However you say it, the answer is still the same. Nothing but Premium in Q's. Newer cars can handle the cheap stuff. But you have a high end luxury import that was designed for people who could afford the good stuff. If Premium gas prices are too much for you right now, then the Q isn't for you. I'm lucky, premium is like $2.69 a gallon here. It'll cost you way more in the long run by not using Premium just to save cash.

Plus, premium burns slower and better.

[96Qowner]

..and also that Lucas fuel injector cleaner. seems to work for 30k but then just wears off

Try BG 44K - much stronger/effective treatment. But ohm your injectors first - your symptoms are typical. And stay away from ethanol if you can - it eats Q45 injectors.

[ericthered]

I didn't have fuel injector problems until I came to California and poured this awful gas into my car. I would NEVER put a used injector from California back in any car.

And a dead fuel injector can cause the Q to shake like heck. I have replaced most of mine with OEMs, but did try two Pythons in my older '92 Q. Before installation I noticed one of them had serious seat smoothness imperfections and cleaned it up. I should have pulled the other one right then, but the installed one had leak down problems too. I had to clean up the seating surface on the other injector too. But all has been well with them since.

If others are considering this experiment to save over $100 per injector, be sure to put the rebuilds in locations that don't require pulling the plenum to remove... you may need to revisit them.

[Haitian_King]

I got a used injector from Colorado.

Works like a dream.

[Romeo5k]

I had this problem as well.... And i did change the coil.. I took it to dealership and they put it on machine, and they said #2 coil.. replaced and still shaked. Come to find out, it was the dang injector, too bad its too late, I found otu its injectore, 1 week after the motor quit on me.!

Question, how did u put regular in there..? When i out regular in my 93, the dang thing would not go over 40 miles an hour. I could floor it, and the rpm would go up and and come completely back down to 1500rpm. and stay at 40mph, even as its floored. But you drove..?? Lucky you. I suggested 2 cans of BG44k with the best premium gas in ur area. If problems come back, start looking at injectors.... The shaking is caused because one is either about to fail, or has already failed! So u are no longer riding on all. Ill see if i can find an archeived thread for u.

[Romeo5k]

here you are... zerothread?id=187957 zerothread?id=255395 zerothread?id=211212 zerothread?id=132458 thes 4 threads will help you to solve ur shaking problems.

[jose310]

alriight thanks, i realise my MAF conector was loose, and i tighetin it up and now its runnings much better just a lil vibration at idle, can it still be an injector?

[goody90q45]

alriight thanks, i realized my MAF connector was loose, and i tightented it up and now its running much better just a lil vibration at idle, can it still be an injector?

Congratulations on fixing you're MAF connector. Cleaning and crimping the contacts are a lot easier than replacing the plug.

You can bet that your bad idle is caused by at least one bad injector. Get a voltmeter and check all 8 fuel injectors and knock sensors at the harnesses located on the passenger side of the engine. It's in a cluster of connectors near the plenum. Follow the instructions in the pic and let us know the readings.

Nice looking Q by the way.

[AlabamaDan]

Man, Q45.org hasnt been updated in years. I really need to... Zzzzzz.....

You sure do Range Rover man!

[AlabamaDan]

Great Pic Mike. People around here are always talking about checking ohms and stuff and it's true that a picture is worth a thousand words.

[Haitian_King]

I'm going to buy a voltmeter and build a Q maintenance toolbox. Keeping assorted screwdrivers in the glovebox and ECU's in the trunk just isn't cutting it anymore. I'll also need a milk crate for my cleaning/winter supplies. Somehow, ATF spilled on my mat in the trunk. Is that thing machine washable?

[Haitian_King]

Whoa. You said your CEL comes on? Might definitely be an injector. More than one. I never got a light but I had a really rough idle and it was my #8 injector. Now, I have a baby-smooth idle. I had to turn my radio off to make sure my engine was still on at a red light.

I'm gonna toss a can of BG in my tank in about 500 miles and get an oil change. I need to get all of my fluid changes synchronized so I can change them all at once, rather than getting things done at odd times.