FI Engine problem - Please help

[iaksa]

My engine (1UZFE sc400 '93 with Richwood M90 kit - 7 psi, over 200K miles) problem starts 4 months ago, I will try to explain as much as I can, hopefully some one can help. First of all what was good, starting engine - ok, idling high 1100 rpm ??, shift to "D" 750 rpm. So, when problem started I notice that at 7psi engine go to red on A/F meter (LED A/F - lean in left 4 cylinders, right 4 - OK) but not too much and only when throttle is open very fast. This is probably related to sucking oil in TB - installed "catch can" to fix - my another thread.
Bigger problem is shaking engine when car is in "D" and not moving, when start moving it is combination of repeated pulling and hesitating and left 4 cylinders in red at A/F or nothing. Looks like problem in left side related to fuel or ignition.
So I changed last week: new OEM ignition wires, new plugs (recommended on this site, /w recommended gap), new distributor caps, new distributor rotors, ultrasonic clean injectors (Supra 315 cc/min), new fuel filter. Start a car , adjust fuel pressure at 40 psi, but still shaking engine, different (bad) sound from left exhaust pipe. The right 4 cylinders look ok at A/F, but left 4 cylinders not even lean - not all cylinders firing ????. Stepping on gas left side of A/F almoust always lean, right side ok.
After all this changes the original problem still exist, it is even worse - more shaking, and car like this is not for driving. Also there is not check engine light on, no codes.
This problem is probably not related to FI.

Just thinking what next to change or check:
-> injectors wires
-> ignition coils
-> fuel pump
-> some sensors ???

I will really appreciate any help.

 

[cribbj]

What did your old plugs look like when you took them out? What do the new plugs look like?

If you're misfiring, you'll get lean indications on your AFR meter because you're not getting full combustion, and hence there's a lot of air in the exhaust. Double check your ignition wiring, and make sure you didn't make a mistake when you installed those new plug wires, and perhaps crossed two cylinders in the firing order.

It's odd that you're not throwing any codes with it running as badly as you say. Also check your timing belt carefully; you may have jumped a tooth on one bank or the other.

Try to confirm the injectors are firing OK - you can do this with the traditional mechanic's stethoscope, which is nothing but a long screwdriver. Hold one end on an injector, and put the other end to your ear, then move to the next injector, etc. See if the sounds of the injectors firing varies from side to side, or even from injector to injector.

If you haven't done one in awhile, I'd run a compression test and see how balanced all the cylinders are.

 

[iaksa]

Oooo, they look very bad, specially on left side, specially two of them (left) third from the front of engine - very bad, and second from the front was not even tight enough - bad. Looks very bad installation, that is why I am trying to do by myself and learn. I had OEM sparks with .040-.044 gap (I paid them to put new one, colder, with right gap - they did not).

-> I used this time BKR7E - NGK Part no. 6097 with .032 gap (.031-.035 recommended).
-> I will check ignition wiring again, when I changed it I check them few times and all wires fit perfectly (OEM) - not sure if is possible to cross it ?
->> Check your timing belt for jumped a tooth ?? What is a easy way to do this, what should I look for, how can I now if is jumped or not ??
-> I will check injectors, like you explained
-> I did not run a compression test so I will think about that too.

Thank you again for your help.
Iaksa

 

[XR8tt]

Try clossing plug gap alittle more ?? Run meg over leads ??

 

[kc95sc400]

If you have two plugs directly next to each other that are badly fouled, you may want to do the compression test that cribbj reccomended.

Easy to do. And...if your head gasket is blown, you'll be wasting alot of money putting parts on it that won't fix the problem.

KC

 

[XR8tt]

The two fowled plugs could have crossed leads ???
To check timing belt ? Just turn engine over till its on compression stroke on #1...Check timing marks on cam gears and balance....
From memory the marks on cams gears are approx 10 and 2 o'clock ...
Not horizontal like most engines...
This should help..Pictures worth 1000 words...
http://www.lextreme.com/valve_clearance.html

 

[iaksa]

Thanks XR8tt

I did some investigation, so far I found this:
I check all old spark plugs, just one (not two) was very bad, cyl # 5. When car is running I unplug injector connector #5 - almost no difference, so does not even work. Check all spark wires with manual, everything is correct connected. Check ignition coils (resistance range) both OK. Then, check compression, and the problem is in cylinder #5, so it is not problem with fuel supply, injector, injector wire, spark plug/wire. I measure compression, and made mistake, did not warm engine enough to normal working temperature, it was almost cold. I did that last night, so I checked five cylinders - dry test, two on right, two on the left, plus suspicious cylinder #5. All four were in the range from 205 psi to 212 psi. #5 cylinder had JUST 45 psi !!!. I did not have a time to do wet compression test - will do today or tomorrow. I do not now how much difference in numbers will be with warmed engine, but difference will probably stay same.

Can somebody tell me what most likely problem is (very low 45 psi) ?
Is it valves seal, head gasket, or pistons ring and cylinder bore or somethings else ?

I will probably have more information in the next few dates.

Any help will be welcome.

Iaksa

 

[JustenGT8]

You have cracked a piston ring land for sure...probably had some light detonation you could not hear (when you had the oiling issue i would say). Time for a rebuild or engine swap unfortunately.

 

[NZ_V8farmer]

i know the pain you feel, ive had to go through alot of issues with my converted hilux, thanks to gloverman who has saved the day. just glad i havent got compression issues. hope goes well and maybe time for high performance rebuild??????

 

[XR8tt]

If plug is oiled up? YES ring lands on piston.. I'd say it'll have some blowby too ?? Fit a hotter plug in that cylinder for time being, just to keep it going...While you consider what you want to do??

 

[iaksa]

I think you (JustenGT8, NZ_V8farmer, XR8tt) are all right, broken ring. When I do compression test I can hear clicking noise coming from that cylinder. Yes, oiled plug, a lot of oil in M90 intake even I installed "catch can" and drive just 2-3 miles. It is time for high performance rebuild.
I will not drive daily this car, just wondering how many miles can go without more damage to the rest of the engine ?

Again, Thank you for all your help
Iaksa

 

[cribbj]

No offense to the 1-2 reputable engine builders who are on here, but builders here in the US will jerk you around for a year or more before you get your motor, and you'll probably not be happy with the end result.

Save yourself the heartbreak & hassle, and just buy a short block (or long block) from David. He's offering them at (l)extremely good prices IMO, and no, he's not paying me to say this!