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Alright guys im at a point where im frustrated and ready to give up.

The other month the mirage started leaking oil from the front side of engine....pulled timing cover and discovered that the oil pump seal was blown out (which was only 1 year old. ) I replaced all seals on the front side as well as the timing belt. Now here's the pisser, cranked the car up after completing said work, and i'll be damned if it wasn't skipping very slightly. Not a dead skip just a very slight skip, to me its like the car is loading up and runnin way too rich, (but is not running rich just an EXAMPLE.) Car produces no black smoke what so ever, and plugs check great.

I checked ALL timing marks over and over, everything is correctly in time. This was not my first t-belt job by any means.

Pulled the plugs (which looked fine!) and did a compression check, 120-125 all across the board and it has 189k miles!

Then checked vacuum lines and found no leak or unplugged hoses.

Then I replaced the pcv valve which I found was bad, still skips.

Next to be replaced were the injectors, I thought maybe one was sticking. Changed out with a known good set and still skips.

Next on my list was the MAF. I replaced it with a known good 1g and still skips. But here's where it gets interesting, with the MAF plugged in the car runs as stated. However, when you unplug it it idles fine.

Last on the list was the egr valve. Pulled it cause maybe it was stuck open, and of course not. And it broke a bolt off in the intake manifold which is too short to get a stud extractor on

It is an 89 turbo mirage, 1.6l, small 16g, 1g MAF, 1g fuel rail, UNCRUSHED 1g FPR, 450cc injectors, 1g bov, 3" exhaust, walbro 255 pump, k&n filter, and a hallman mbc set to 12psi. Ecu caps were recently replaced also. (This exact setup has been used for 2 years without the first issue. Only thing that changed was the t-belt and oil seals, then skip developed. THEN, I just changed said parts for EXACT spare, known good parts. Nothing else was changed. Had no driveability or fuel issues with car prior to this.)

Any help is appreciated. My dad recently had a stroke and I have no help anymore when it comes to this. The only thing I know left to do is pull the motor and put my 2.0 in it but its not completed.

Thanks in advance,
Scott

I would replace the plugs and wires since they're fairly inexpensive. Funny how it doesn't skip with the maf unplugged which I believe puts the engine in limp mode. Do you have another coil or ptu to swap out?

_________________
93 Mitsubishi Expo LRV 1.8/manual
95 Eagle Summit DL Coupe 1.5/manual
01 Mitsubishi Mirage ES Sedan 1.8/manual

I would do what 89mirageman said and also check the o2 sensor....I would recheck your timing marks to i had bought a car it had a mis or skip at idle ended up being the intake cam was off a tooth fixed that and the mis went away...

_________________
Str8fuct......
11.6 @ 122mph bone stock 4g61t with a 16g brah...

Do you have an afp to go with that 255 pump?

_________________
Had a:
1991 Eagle Summit ES Hatchback - 4g15 12v 5spd
1991 Dodge Colt -4g15 12v 4spd
Have a:
1978 Oldsmobile Cutlass - 468BBO TH350
Round 3:
1990 Dodge Colt-4G63T 5spd

I run a stock fpr with my 255 wally idles just fine....

_________________
Str8fuct......
11.6 @ 122mph bone stock 4g61t with a 16g brah...

And I had to turn down my afpr by 10psi when I swapped in a 255hp.

_________________
Had a:
1991 Eagle Summit ES Hatchback - 4g15 12v 5spd
1991 Dodge Colt -4g15 12v 4spd
Have a:
1978 Oldsmobile Cutlass - 468BBO TH350
Round 3:
1990 Dodge Colt-4G63T 5spd

Instead of randomly replacing sensors read the codes first. Sound like you are running rich, i.e. 450's + 255 with a stock ecu.

_________________
05 wrx wagon
99 Benz ML 320
91 eagle summit swapped - 6/4 bolt combo
94 Audi s4 - sold
88 Eagle Vista Turbo LX sedan, RIP

It has been running on a 1g MAF, 1g fuel rail, 450s, and an UNCRUSHED 1g FPR with the 255 walbro for over 2 years now, with no issues.

Possibly because you are running a 255HP. It's ran with the 255 just fine with a stock 1g UNCRUSHED FPR for over 2 years now.
As does mine hemi.
It hasn't thrown the first code to be checked. It just idles roughly, IMO like its loading up, but it's not smoking black rich smoke.

Also, it has been running with a 1g MAF, 1g fuel rail, 450s, UNCRUSHED 1g FPR, 255 Walbro, and a stock 1.6L EPROM ECU for over 2 years, without the first driveability issue at all.

Oh, this isn't my first t-belt job either, as stated. Marks were checked and double checked before it ever got reassembled.

It's possible your old timing belt was stretched out and your valves were closing late letting some of the rich mixture out before they closed giving you a good idle and now with your valves closing when they're supposed to, the ultra rich condition is showing itself.

_________________
Had a:
1991 Eagle Summit ES Hatchback - 4g15 12v 5spd
1991 Dodge Colt -4g15 12v 4spd
Have a:
1978 Oldsmobile Cutlass - 468BBO TH350
Round 3:
1990 Dodge Colt-4G63T 5spd

The timing belt and all seals were changed approximately one year ago. As stated the oil pump seal blew out (which was only one year old.) That is why I wound up changing the seals and the belt again...because the belt was oil soaked and now ruined

Previously stated, the car ISN'T puffing black smoke and the plugs look great. I was using that to try to let people know what the car sounds like when it is running.

If it didn't skip when it had a brand new timing belt on it one year ago i doubt it is running rich man.

Isn't a 255, 1g MAF, and 450s a common set of mods on these cars?

So is my Evo running too rich with a stock Ecu, stock fpr, 880s and a 255hp? No, it isn't. I understand an Evo isn't a mirage btw, just another example.

And I'm letting you know that I had the exact same issues with sputtering and bad idle and the cause was too high of fuel pressure. It's been my experience that people that swap in a 255 and use the stock fpr usually have some kind of other problem that's letting the rich condition slip by them and when they fix that, all of a sudden they have a crappy idle and the car doesn't run right and they have no idea what could be causing it because "it ran fine before".

_________________
Had a:
1991 Eagle Summit ES Hatchback - 4g15 12v 5spd
1991 Dodge Colt -4g15 12v 4spd
Have a:
1978 Oldsmobile Cutlass - 468BBO TH350
Round 3:
1990 Dodge Colt-4G63T 5spd

Also, you stated yours was a 255hp, mine is just a 255. The HP does put out a little more pressure correct?

I have been told by my tuner, I can run a 255HP single pump setup, and run E85. But if I were to use my 255, it would have to be rewired. (of course with E85 I'll have to have an AFPR, bigger injectors, and DSM link.)

Maybe since you used the 255HP your pressure was higher? Thanks for the insight.

The only difference is that at higher pressures (around 65+), the flow in the 255hp doesn't drop off the same as the 255, the flow is the same as the regular 255 until then. Check your fuel pressure, it may be higher than you think.

_________________
Had a:
1991 Eagle Summit ES Hatchback - 4g15 12v 5spd
1991 Dodge Colt -4g15 12v 4spd
Have a:
1978 Oldsmobile Cutlass - 468BBO TH350
Round 3:
1990 Dodge Colt-4G63T 5spd

The Wallz 255 flows more than the OEM pump... PERIOD. Please check your current pressure and advise of your findings.....

_________________
Geoff
2013 Genesis 5.0 RSPEC
88 Mazda Turbo II- LSX7
89 2.0 Turbo Colt
13 Ducati 1199 Panigale