87 325is low on power

[PoorBoysRacing]

So a bit ago my e30 was missing bad, only running remotely right in high rev ranges ect. Found a big vacuum leak, fixed that, changed plugs,
old plugs were white (running lean replaced with copper) and my fuel filter which was full of crap (may have even been OEM) that fixed the bucking and the missing.

But now although the car runs smooth as can be its drasticly low on power, my e36 318 pulls harder now :puppy:


I checked the fuel pressure, all within spec.

It has great vacuum now.

car fires up quick and idles great.

Im kind of stumped.

My next though was maybe dirty injectors? (pull them out and clean them)

Goal is to have the car set my the 25th (next rally cross)

any suggestions?

[jlevie]

Is the engine down on power throughout the rpm band? Or does it recover above 5k? In the first case dirty injectors, a bad TPS, or a mistimed cam are possibilities. In the later case a bad AFM is a possibility.

Check (at the DME connector) for operation of the WOT switch in the TPS. If it isn't good the DME won't know that the throttle is wide open and thus won't use full throttle maps. This will affect the engine operating range, but will have a greater affect above 5k. Also make sure that the cam timing is correct. A tooth off will noticeably affect power. I'd also check to make sure that the ECT sensor is in spec.

The easiest diagnostic for the AFM, if the engine is down on power only below 5k, is to swap in a known good unit. As for the injectors, having them professionally cleaned and flow tested is the best approach. I like RC Engineering for this.

If you can't find any faults that restore normal operation, I'd suggest putting the car on a dyno and seeing what the A/F curve looks like. If that data looks odd, swapping in a different DME and making another pull might have a big affect. What to do if that doesn't help depends on what the curve looks like.

[PoorBoysRacing]

The car has no power through any RPM range, when it was missing and bucking it would clear up above 4k or so. But since that Problem was resolved(ish) it has a lack of power throughout any RPM.

is there any adjusment besides a jumped tooth for timing on the M20? I know with my classic cars it was adjusted by turning the distrubuter, was wondering if something could have losened up during rally x and allowed the timing to become out of wack.

thanks for the advice, its greatly appretiated.

Ive been scratching my head for awhile now.

[jlevie]

There are no adjustments on this car other than cam timing. The engine management system assumes that data from the sensors is valid and controls the engine based on that data. So any problems have to be within the DME or with the data its is receiving.

[PoorBoysRacing]

good to know, thank you.

[PoorBoysRacing]

ordered a new set of injector o rings so i can give them a clean, also ordered a new o2 sensor since the previous owner told me the car used to throw an o2 code occasionally,

anyone have a link to a DIY TPS test?

ive been searching but havent been able to find out how to do it.

thanks for all the help guys, there is a winter driving school and a night rally cross next saturday that I want to attend so challenge accepted.

[PoorBoysRacing]

My GF gave me a 50 dollar ebay gift card for Vday and guess what i just paid for a new TPS...50 bucks shipped ha ha, so hopefully betwwen the cleaned injectors, new o2 and new TPS she will run properly again :crosses fingers:

[frolf]

I would love to hear an update on how your car has fared after the things you mentioned in the above two posts.

Dan