I have just bought my mk3 and drove it for about a month then went to the beach and after a while of driving it, it started to like missfire. It wouldnt rev past 5 grand and it jumped alot. I thought the spark plugs or wires so i replaced the plugs and the wires look brand new. I've tried to get someone to hook it up to a comp. but he said it wasnt in his. Also the check engine light never comes on when it starts to missfire. I don't know what it is, I think either the toyota place messed with my ecu (i unpluged my o2 sensor and the check engine light didnt come on) or the coil packs. Can anyone help?
Weird jump.
- Thread starter mk3_chris
- Start date
If you have coil packs, its turbo, and you're in the wrong section. Have you checked fuel pressure? When the o2 sensor went out on mine, it didn't trip the c.e.l. I have one of the best diagnostic machines available today, and it doesn't connect to our cars, just tells you what to jump in the diagnostic box. Here's how you check for codes: http://cygnusx1.net/Supra/TechTips/engine_error_codes.aspx
Have you checked for vacuum leaks? Maybe a bad igniter? There's to many possibilities without checking the codes.
Have you checked for vacuum leaks? Maybe a bad igniter? There's to many possibilities without checking the codes.
my 86.5 used to do a similar thing, only sometimes... for me it turned out to be the #3 injector plug had come loose, did not look loose, but it was.
pull each one of them and make sure the contacts are clean, and no clips are broken, mine sounded fine at idle then when under load it would just dump fuel into the exhaust on #3 creating a misfire, its worth a look.
pull each one of them and make sure the contacts are clean, and no clips are broken, mine sounded fine at idle then when under load it would just dump fuel into the exhaust on #3 creating a misfire, its worth a look.
Don't think either of those would cause a misfire. You don't need to take it to a shop to check for codes, you can do it your self: http://cygnusx1.net/Supra/TechTips/engine_error_codes.aspx As CRE mentioned, oil in the plug galley is very common, and would cause a random misfire. Could also be a loose connection at the distributor, injectors(like pres6 said), coil, bad wire, any number of things. Check for the codes yourself, and get back with details.
These guys know what they are talking about. I believe you can still have codes thrown with the light not on. You have to short the terminals like it says in the manual to get the codes. They won't reset until you disconnect the battery. There is several things that could cause your problem as they stated from plugs to distrubor cap and oil in the galley to injectors. If it was me I'd check as many things out that I could before I took it to a garage and paid them moocho bucks to do the samething.
You said you changed the spark plugs, what kind of plugs and did you gap them? Was there oil on the end of the plug wires? When you took off the TB, was there dirt or oil inside? Did you check the distrubritor cap and rotor? Did you have somebody check the timeing? There is several things that can cause your problem without throwing a code. Most are maintance type things that if you keep up with your NA will be very dependable. If you just bought the car you should go thru everything to see how well it's been kept up with. If something doesn't look right then post a question to see if it's normal or not. Like I've said there are several things that can cause your problem and you will have to narrow it down by checking out step by step the related parts.
You should still always check the gap. If they were Champions, pull em out and throw them away. NGK is what you need to get. I've had new Champions right from the box be bad. How long has the fuel filter been in there. Somebpdy on here had a injector wire loose, didn't look loose. That's another thing that could be dirty. Try some Chevron Injector cleaner in the tank.mk3_chris said:
Could be, could be fuel filter, I think I mentioned that already. You'll have to get a FP gauge to check and see if your FP is with in tolerances. Could be the FPR, or the FP resistor or relay. There is ohm meter checks in the TSSM for those. Have you checked your TPS?mk3_chris said: